OFFICERS FOR 1896-7.

President : PROFESSOR E. W. Craypo.e, B. Sc., F.G.S...... Akron, O.

Vice-Presidents » C. C. MELLOR. . . tae 4s 2s -« PIttSbuneeeaee

A. M. BLeize, A. M_., M. D. owes ee «COMES es

Secretary Mg! C. Krauss, M. D., F. R. M. St: 2. . » Buffaloes

Treasurer’: MAGNUS PFLAUM ... «+ +... ++ «. = « Pittsburg, Pa.

ELECTIVE MEMBERS OF THE EXECUTIVE COMMITTEE.

A. A.. YounG Me Ws hoe eS ee 5s ee, oe ok ieee Leto

oo S.PSGace ees. Fie Jee he pe eee ee) ae eee a hie ee

. P. Manton, M. D., E. R. M. S. reemermrernerie eer ee Dysisvoyles ice a

PAST PRESIDENTS.

Ex-officio members of the Executive Board.

1. R.H. Warp, M. D., F. R. M. S., of Troy, N

an ‘Indianapolis, Ind., 1878.

R. WARD, M.D: B. Ry MES] of Broy,, N: ¥.,

at Buffalo, N. Y , 1879.

3. H.L. Swrru, LL. D., FR: M. S.-of Geneva, N. Y,,

at Detroit, Mich , 1880.

4. J.D. Hyatt, F.R. M.S., (absent), of New York City,

at Columbus, O., 1881.

5. Geo. E. BiackHaM, M. a F. RoM.-S., of Dunkick, Ns

at Elmira, N. -Y.5 18825

6, ALBERT McCatta, Pu. D., F. R. M. S., of California,

at Chicago, Ill., 1883.

7. .J. D..Cox, LL. D., F. R. M. S., of Cincinnati, Ohio,

at Rochester, N. Y., 1884.

2) Heb. Sire bee D., PAR: MoS of Genevas Nees

at Cleveland, Ohio, 1885.

g. T.J. Burritt, Pu. D., F. R. M. S., of Champaign, IIl.,

at Chautauqua, N. Y., 1886.

10. Wm. A. Rocers, A. M., F.R.M.S., of Waterville, Me.,

at Pittsburg, Pa., 1887.

11. D.S. Ketticott, Pu. D., F. R. M. S., of Columbus, Ohio,

at Columbus, Ohio, 1888.

12. Wm.J Lewis, M.D., F. R. M.S., of Hartford, Conn.,

at Buffalo, N. Y., 1889.

Sof Buttaloy Nowe.

at Demos Mich., 1890.

14. FRANK L. James, Po. D., M.D., F.R. M.S., of St. Louis, Mo,

at Washington, D. C., 1891.

15. MarsHacy D. Ewe tt, M.D., F. R. M.S., of Chicago, Ill,

at Rochester, N. Y., 1892.

16. Jacos D. Cox, LL. D., F. R. M.S., of Cincinnati, Ohio,

at Madison, Wis., 1893.

17, Lester Curtis, M. D., F. R. M.S., of Chicago, Ill,

at Brooklyn, N. Y., 1894.

13; GEO. EB. Pe.e,-MsD.; PAR. M.

18. Simon Henry GaGE, B. S., of Ithaca, N. Y.,

at Ithaca, N. Y., 1895.

19. A. CuirForp Mercer, M.D., F. R. M. S., of Syracuse, N. Y.,

at Pittsburg, Pa., 1896.

The Society does not hold itself responsible for the opinions expressed by members in

its published Proc eedings unless indorsed by a special vote.

PROCEEDINGS

The American Microscopical Society.

MINUTES OF THE NINETEENTH ANNUAL MEETING

HELD AT

PITTSBURG, PA., AUGUST 18, 19, 20, 1896.

TUESDAY, August 18, 1896.

The members assembled in the Carnegie Library Building

at 10 A. M. and were called to order by Mr. C. C. Mellor, of

Pittsburg, Chairman of the Local Committee.

Members of the American Microscopical Society, Ladies and

Gentlemen :

To my lot has fallen the pleasant and honorable privilege

of beginning the exercises preliminary to the nineteenth

annual meeting of the Society, and on this occasion, I will

introduce to you two gentlemen, one of whom will make the

address of welcome and the other the response, as it were

touching the button, and these two gentlemen will do the rest.

For the address the committee has been able to secure the

citizen who is the best able to make it, one whose attainments

are known the world over in his particular line and who is

also at the head of the highest educational institution of this

city. I have the honor to introduce to you Rev. W. J. Hol-

land, Chancellor of the Western University of Pennsylvania.

Mr. Prestdent, Members of the American Microscopical

Society, Ladies and Gentlemen :

It is a very great pleasure to me on behalf of the local

scientific societies and the citizens of this town to extend to

4 PROCEEDINGS OF THE

you on this occasion a most cordial welcome. Hospitality, as

you all know, is an ancient grace and virtue, and I have heard

it said by Pittsburgers that they excel in this virtue, and I, in

fact, have heard others that have been in Pittsburg venture

to intimate that the claim is just. There have been some

historic interruptions to the hospitalities shown by Pitts-

burgers, notably when General Braddock kept the Indians on

the other side of the Monongahela River during the French

and Indian War. But away back in the days when Queen

Aliquippa entertained George Washington, running down to

the present time, there has been courtesy shown to the

strangers, save and except when Captain William Trent, about

1772, acted rudely to the Indians who were rude to the Eng-

lishman, General Braddock. But these are all facts known

to history, and the people of the present day may be relied

upon to accord to you in their homes and in all the relations

you may meet them a hospitality that will be personal. I

welcome you as representatives of the learned of the nine-

teenth century. It is said of the most famous of the ancient

Hebrew kings, accounted the wisest of his day, that ‘‘he_

spake of trees from the cedar which is in Lebanon to the

hyssop which springeth from the wall; he spake also of beasts,

creeping things (reptiles) and fishes.” From this you will

observe that King Solomon’s knowledge was confined in

botany to the phanerogams and that his knowledge of his-

tology extended no further than to the lower vertebrates.

He knew nothing of spores and bacteria ; all the wonders of

mycetology and cryptogamic life were hidden fromhim. He

knew nothing of the protozoa and the myriad forms of micro-

scopic life with which you are familiar, representing the

wonderful advancement of modern science achieved through

the microscope. I welcome you as those who are wiser than

Solomon, and who know more than the ancients, and trust

from intercourse with you to add to the stores of knowledge.

I welcome you as friends of humanity. People sometimes

wonder why men should spend their time investigating mere

minute organisms, spending months and hundreds of dollars,

AMERICAN MICROSCOPICAL SOCIETY. 5

From the peculiarly economic standpoint, the investigator

himself reaps very little return in fame or wealth, but the

pathway is broadened and made plain to discoveries which

enrich the world. You are representatives of those who with

the microscope have carried our knowledge downward into the

deep, while the astronomer gazing upward has made his way.

Nature is most to be admired in things that are least known.

I welcome you in this ancient city, the city of industries,

in which you will find anything that you wish to see, from a

beautiful spectroscope, perfect in all its adjustments, to the

grosser parts of such a mechanism as the man-of-war ; where

we make anything from a tack to a locomotive or an oceat

steamer. I welcome you toa city in which we have some-

thing more than industries. Standing on the companion-

way of a steamer a few days ago, I overheard a young lady

say, ‘‘ Where are those people from?” Her escort replied,

‘From Pittsburg.” She said, ‘‘Where they have nothing

but smoke and money.” We have a great deal of smoke at

times and there is a little money to be picked up in odd

nooks and corners, I am told by some. But we have other

“things. This beautiful building, the gift of one of our citi-

zens, the home of art and science; also the extensive park

and conservatory. We have schools, colleges, hospitals and

churches and learned societies and all those things that go to

make the city a desirable place of residence in spite of its

smoke. We have something better—a disposition to grow

in knowledge and to make advancement in all lines open to

us.

In the name of my fellow-citizens and the Iron City

Microscopical Society I extend to you all a most hearty

welcome.

Mr. C. C. Mellor—I now take pleasure in introducing to

you the President of the American Microscopical Society,

Dr. A. Clifford Mercer.

Dr. A. C. Mercer—President Holland, to you and the soci-

eties you represent and the citizens you represent, the society

6 PROCEEDINGS OF THE

tenders its thanks for your words of welcome. The hospi-

tality of Pittsburg is notan unknown quantity to this society.

This society met here nine years ago and that meeting has

gone on record as one of the best the society has ever had

and we have no doubt this meeting will be at least a parallel.

We know to some extent—probably only to a small extent,

comparatively—something of the work done in Pittsburg to

bring about this welcome, and for all those labors we are

thankful. I have very little more to say. Personally, I

belong to a calling which practises rather than preaches and

it will be in accordance with that practice if we begin our

work at once; therefore, I will declare the nineteenth annual

meeting of this society open.

The names of a number of new members were then read,

as recommended by the executive committee, and by resolu-

tion the secretary cast the ballot of the society for them and

they were declared elected. They will be found in the list

of members at the end of the volume.

Miss Edith J. Claypole, of Akron, Ohio, then read a

paper on Notes on Comparative Histology. :

Discussion :

Professor S. H. Gage—I suppose everyone who has used

the microscope has studied this subject. It seems to me very

suggestive that a subject that has been gone over so often

has had a little new life put into it. Miss Claypole has con-

sidered it from the physiological instead of from the mechani-

cal standpoint. There are at the present day two great

schools of physiologists, those that believe physiology is

refined mechanics, and those that believe it is something

more than ordinary mechanics. Evidently she considers that

physiology is something more than ordinary mechanics.

This paper has another beautiful feature about it that

shows to the older ones as well as to the younger that there

is not any subject exhausted yet. Every increase in knowl-

edge makes an old subject a new one, and this subject has

been made alive and interesting. It gives us more physio-

AMERICAN MICROSCOPICAL SOCIETY. Fi

logical insight, and so I feel sure that all of us will work with

new zeal, and we hope next year Miss Claypole will bring

with her some new tissues. I am sure she will be ahead of

any of us.

Mrs. S. P. Gage—lIt has been very pleasing to notice in

this study that the evolution of tissues is coming to be con-

sidered of equal interest with the evolution of the grosser

structures.

Professor E. W. Claypole—We have the evolution of these

tissues and these animals toconsider. Unfortunately, froma

geological standpoint, we can not get tissues, except in a few

cases, to replace what these ancient creatures possessed in

this respect. If we trust the embryologists, there must have

been some change going on in the course of evolution of

these animals on the earth, and it occurred to me that that is

partly connected with the change that took place when land-

life first began. As long as the reptiles were confined to the

sea the animals possessed the advantage of breathing through

their skins, but land-life deprived the animals of the power

of breathing through the skin, and thus was increased burden

of breathing through the lungs. The change took place

somewhere in reptile life; that change was accompanied by

the necessity for greatly increased oxidation of blood in the

lungs.

We also have to consider such a question as this: Why

should the camel alone among the mammalia possess these oval

blood corpuscles? That is a question not yet answered by the

paleontologists. The lamprey may be regarded as a highly

specialised parasitic creature, because it sucks the blood of

other creatures. The lampreys can be carried back to the

Devonian era, and if they possessed blood discs almost spheri-

cal, then these must be perquisites of very ancient vertebrates.

If the lamprey goes back to the Devonian age, it counts

among the very early ones, and we have a nut to crack in

this case. For that reason I think the possible outcome of

this investigation may be of considerable interest to the

8 PROCEEDINGS OF THE

members of this society who are interested in that part of the

question.

Dr. V. A. Moore—I wish to endorse very heartily all that

has been said, but I find, in looking at it from another stand-

point, that the paper is very suggestive and opens up many

subjects of profitable study. One of the most important of

these is the diseases of animals. No tissue is more largely

affected than the blood, and although much has been learned,

still so little is known about its variations, changes and sus-

ceptibility to not only solids but those substances recognised

as toxin and antitoxin. This paper opens up the field of the

variability of structure of the blood in the same individual

regarding atmosphere and temperature, food, and soon. I

do not know of an exhaustive treatise on the blood of a

single healthy animal, and it is on the healthy condition that

pathologists base their knowledge of variations. It is

important we should study the condition of the blood in a

single specimen.

President—I think the discussion proves the paper is all

that has been said of it.

The next paper was read by Professor S. H. Gage, on

Courses in Histology and Methods of Conducting Them.

Discussion :

Dr. V. A. Moore—All of us who know something of actual

work as a teacher will realise fully the profit which this prac-

tical talk which Professor Gage has given us will bring to

those who are teaching histology. I was very glad of his

suggestions in the beginning of giving the students some

idea of the practical importance of this work. On the other

hand, although I seem to change a little from my former

statements, I believe in histology for histology’s sake, and

bacteriology for bacteriology’s sake. Teach truth for truth’s

sake and not because it has some value or use one can turn

into dollars. It is this seeking for truth that has led to the

excellent paper of Miss Claypole’s. We must look for truth

to the men who have investigated the structure of tissues for

their own sake. One thing not brought out by Professor

AMERICAN MICROSCOPICAL SOCIETY. 9

Gage is the importance of the study of fresh tissues as well

as those cut and hardened. Our knowledge of malaria and

other disorders has come from the study of fresh tissues.

Going hand in hand with what he said, this would be very

helpful to a student.

Dr. V. A. Latham—lI wish to thank Professor Gage very

heartily for his suggestions. I hope that his forcible remarks

may be made more so by being published, to encourage the

medical colleges to assist the practical teachers. In my

capacity as instructor in the medical college at Chicago, I

find it very difficult to get room for my laboratory work. We

are obliged in medical schools to take up and have in our

classes pupils who have never seen a specimen under the

microscope. We know Professor Gage’s position is one of

the foremost in the country. His classes of students are

really the embryonic workers of the country today. ,

Professor E. W. Claypole—I wish he could get all the

trustees of our institutions together and ‘‘lay it to them.”

If he could get such an audience as that, he might get a few

converts. These remarks should be published and handed

about, then some effect might be produced. As to what he

said about the pathological value of histology, it is a difficult

thing when students ask what is the use of studying histology.

If you cannot talk in a way to make dollars and cents appear

even in the distance, they shun the work. Not one in a

hundred can tell the difference between abnormal and normal

tissues. If I put an abnormal tissue under the microscope

they know nothing about it. They can only send it to a

specialist for examination.

Miss E. J. Claypole—I want to speak on one point especi-

ally. For two years I have been teaching in Wellesley Col-

lege and one of my subjects has been histology. It seems to

me one of the most important points in histology is to give

students the tools to work with, afterwards the fresh tissues

and methods of treatment, and if they have the opportunity

they will be able to get at the structure of the tissues they

have not examined from those they have examined. The

IO PROCEEDINGS OF THE

knowing of specimens and treatment has been of so much use

to me that I could not help speaking of it.

Dr. A. A. Young—I heartily agree with Professor Gage.

He went no further than colieges—why not go to the public

schools, where a child is taught how a drunken man looks

without knowing how he got there?

President—Without calling for more discussion, | will ask

Professor Gage to close it.

Professor S. H. Gage—lI want to refer to just two things.

When I advocated that we should show the students in the

beginning what the good of the work is, I think that is correct,

because unless one has a tremendous inclination for one sub-

ject over another, why should he select it unless he has that

inclination? I want to bring about the study of histology

forits ownsake. -A precious few only are capable of research.

Those who have not this divine quality will get nothing out

of it. But for the few who do have that, you do not have

to tell them to study it for its own sake—they will do it after

they get started. About the study of fresh tissue: I have

said so often in the meetings—tried to impress it last year in

my address—that the study of dead things has very little

inspiration. It is like studying one thousand years from

now the steam engine when we have changed our methods

of transportation. How, under the sun, would one get any

idea of what it was meant for, by taking it all apart a

thousand years from now, supposing nothing remained to

show what it was for? In histology, if we do not study the

fresh specimens, we miss the pith of the subject. We may

study them to get the structure afterwards, but study them

alive and see what they can do. So, when life is in the

tissue we are trying to understand, we can get some inkling

of what it all means. Let us study the live histology and

take the dead only as a necessity.

The Physician and His Microscope was the title of the

next paper, read by Dr. .A. A. Young, of Newark, New

York.

AMERICAN MICROSCOPICAL SOCIETY. it

Discussion :

Professor S. H. Gage—That was not a false picture the

author drew. I knowa real good man and able physician, not

a thousand miles from a certain university, who has just such

a microscope ; very impressing to his patients. How much

he knows about it is this: He bought some specimens and

allowed me to look over them at onetime. The one I exam-

ined was labeled stomach, but was evidently an intestine.

On telling him that the specimen was not from the stomach,

he said the man he bought it from knew more about it than

I did and left the label on. Another brought me the result

of an autopsy and wanted me to say what it was. I looked

at it and told him it was no wonder the man died, because

the pathological product was tea leaves. What I have

always tried to do with the students who come to me is to

tell them they cannot study pathology unless they study

normal histology, and they cannot get it any more than

German in fourteen easy lessons ; and when the students say

they want to get into business as quickly as possible, I say,

‘« Join the army of quacks; they make $50 to a good physi-

cian’s $1, and you will get rich.”

Professor H. N. Conser—lIt is nearly always the case with

physicians that they have had experience with the micro-

scope, but the instruction is faulty. The matter of section

cutting is naturally not very practicable for physicians ; they

can leave that to those who have facilities for so doing. I

think that is a fault in teaching.

The President appointed Professor Gage, Mr. Kuehne and

Professor Kellicott on the auditing committee.

TUESDAY AFTERNOON.

At 3 o'clock the members assembled in the lecture room and

were then conducted through the beautiful Carnegie Library

building. Mr. Cunningham, the superintendent of the build-

ing, acted as guide and led the party through the museum,

reading rooms, to the library proper, where the society was

LZ PROCEEDINGS OF THE

received by Mr. Anderson, the librarian. The alcoves,

indexing room and study rooms were then inspected, and as

the party was about to enter the auditorium an envelope was

presented to each member, enclosing a card inscribed as

follows: ‘‘Souvenir, nineteenth annual meeting of Ameri-

~can Microscopical Society, at Carnegie Library, Pittsburg.

Visit to Music Hall, August 18, 1896, at 3 o'clock Paamm

Program: Andante in G, Calkin; La Cinquantaine, G.

Marie; Reverie, Batiste; Overture, ‘Zampa,’ Herold; Hymn

of the Nuns, Wely ; Traumerei, Schumann ; Offertoire, 7

Organist, C. C. Mellor.”

After thoroughly enjoying the organ recital, evidenced by

the frequent and prolonged applause during and following

Mr. Mellor’s rendition, the society wended its way to the

Phipps conservatory, in Schenley Park. Perhaps no conserva-

tory in America can compare with the rich treasures of plant-

life contained here, and the beautiful and rare species were

greatly admired.

Tuesday evening, about 8 o'clock, the society assembled

in the lecture room to listen to the annual address of the

president, Dr. A. Clifford Mercer, of Syracuse, N. Y.

WEDNESDAY, August 19, 1896.

Meeting called to order at 10 o'clock.

President—Our first business is the nomination of a

nominating committee to consist of five, and to report at

the business meeting tomorrow. It will be satisfactory to

the society and the executive committee if these business

matters can be given as little time as possible, so that here-

after we can give almost all our time to papers and the more

legitimate work of the society.

The members proceeded to nominate the following: Pro-

fessor H. N. Conser, Professor D. 5. Kellicott; Dra Vas

Moore, Miss E. J. Claypole, Professor S. H. Gage.

President—It is moved and seconded that the secretary

cast a ballot for these candidates as members of the nominat-

ing committee. Carried.

AMERICAN MICROSCOPICAL SOCIETY. 13

Ballot has been cast in favor of these gentlemen and lady

and this committee will report Thursday afternoon.

The names of a number of new members were then read

_as recommended by the executive committee, and by resolu-

tion the secretary cast the ballot of the society for them and

they were declared elected. These names will be found in

the list of new members at the end of the volume.

The paper of Miss Isabella M. Green, was presented by

Professor S. H. Gage, on Ciliated Peritoneal Epithelium in

Amphibia.

The next paper is on Photo-micrography, by use of ordinary

objectives practically considered, with specimens of work by

Thomas J. Bray, of Warren, O.

President—This eminently practical paper is open for

discussion or questions.

Professor S. H. Gage—I would like to speak of one little

device for the use of students. -If we let these lines repre-

sent the camera and put an object on the floor there, we get

strong shadows. We took the camera in its usual position

' and, in place of having an opaque object took a piece of

glass, under which we put a white paper. That is very

impracticable when we come to photograph large specimens,

however.

President—We shall have in our proceedings a paper upon

similar lines by another gentleman. Such papers will make

our proceedings rich in this sort of practical instruction.

None of us who has done any photo-micrography has listened

without gaining some practical points out of the paper. And

I think we have to thank the gentlemen who are not so much

interested in tissues and the like, but give us the results of

such work. Men who are busy in histological laboratories

have little time to do such work. You will notice on the

back of the photographs some notes. If everybody in pre-

senting photo-micrographics for any purpose would give us

similar notes it would be of immense value ; such notes ought

to go with all photo-micrographics.

14 PROCEEDINGS OF THE

In regard to the yellow screen, not only has it the value

mentioned, but undoubtedly a yellow screen makes an objec-

tive which alone would not do good photographic work,

capable of doing such work by photographing with the same

yellow light for which the objective is corrected for visional

purposes.

Then the third point. I think a word ought to be said

about doctoring and improving negatives. That is all well

enough from Mr. Bray’s standpoint, to make attractive pic-

tures, but when using a negative for scientific illustration

it should not be touched in any particular; many a point

may be developed or excluded to suit the imagination or

theories of a person who is writing a paper, just as in

the drawings; but the cardinal rule is that the print

should come from the untouched negative, and the first

negative and not the enlarged one, because in the act of

re-photographing you may introduce changes. If we are

making photographs for exhibitions and details are not

important, then this is beautiful; but if beauty is not the

object, but some truth we are after, the negative should

never be touched in any of these ways.

Mr. T. J. Bray—I did not mean to touch the object, but

simply the surroundings and show the object up more sharply;

the negatives have not been re-touched, but simply the

background.

The vice-president, Mr. Pennock, then took the chair,

while the president read the next paper, on Astronomical

Photography with Photo-micrographical Apparatus.

Professor S. H. Gage—Dr. Mercer in his papers usually

covers the ground so absolutely and brings in matters that a

good many of us are not familiar with. Certainly to have a

matter of this kind brought before our society with the prac-

tical demonstration we have here of its results, is one of the

gratifications we have in our annual meetings. Things come

up most of us never thought of, and it certainly never

occurred to me to try this on the sun and moon ; but if it is

AMERICAN MICROSCOPICAL SOCIETY. T5

not any harder than it seemed to be, I think we will all be

observers of eclipses after a while.

The next paper, Notes on Technique, by Dr. P. A. Fish,

of Washington, was read by Professor Gage; also a paper by

the same author, entitled Zoophily versus Homophily.

Dr. V. A. Moore—I intended to prepare a paper for this

meeting on the importance of animal experimentation, but on

account of stress of work was unable to do so. It seems

necessary to bring a few facts before the society, coming as I

have from the hot-bed of this contest. It is difficult to tell

just who started this bill originally, but it was presented by

Senator Macmillan, of Michigan. It was brought by certain

people belonging to the anti-vivisectionist society. They

planned a bill entitled, A Bill for the Further Prevention of

Cruelty to Animals in the District of Columbia. It is not

necessary to read this, as it is quite an extensive document...

While they had not claimed that they wished to prevent ani-

mal experiments, the bill if passed will prevent further investi-

gation of the government in this line.

In the first bill presented to this committee, the law required

that licenses should be issued by the District Commissioners to

all people engaged in vivisection, and the District Commis-

sioners should exercise judgment as to who were fitted to

perform these experiments, putting into the hands of the

District Commissioners the power to grant these licenses,

which must be obtained for every experiment. These per-

mits must be obtained five days before the performance of

the experiments. You who are familiar with animal experi-

mentation know that a delay of five days is sufficient to

spoil all good that may possibly come from such work.

You see it practically stops all work. In addition to

that, these Commissioners were to appoint a committee of

three from the Humane Society, so-called, who were to

inspect laboratory work at any time they choose. You must

open the doors and explain the investigation or experiment

and stop all work and make an elaborate report to the Dis-

trict Commissioners whenever requested to do so. ‘This bill

16 PROCEEDINGS OF THE

came up before the District Commissioners and was opposed

with as much argument as possible, but to no avail. The

anti-vivisectionists procured a very oratorical lawyer and

statements of experiments made in France thirty or forty

years ago, and were successful. They did modify it some-

what, so that the committee should be appointed by the

president and not by the District Commissioners. While it

seemed unreasonable to think this bill could be reported, it

was, and I have here the report on the same. It shows that

the senators were fair in incorporating a good portion of the

argument in opposition to it. It is on the calendar of the

United States Senate and may pass that body immediately

after convening of Congress in December. The people

anxious for this bill have circulated petitions and have

secured signatures of a great many men of prominence,

bishops, clergymen and physicians. One of these has

written Bishop Hurst a letter, saying that it was presented

to him to prevent vivisection in schools, etc., in the District

of Columbia, and we have found from consulting other

people that they considered this bill of that character, and

not of the sweeping nature it really is. It is one of the

most outlandish, unreasonable combinations of proposed

legislation that I have ever read, and its influence can

be seen from the fact that these men and women who in

the State of Massachusetts tried to get similar legislation

through and then admitted that, if they can get this bill

through Congress, they can use it in getting state legisla-

tion, so that really the time is coming when this country will

be in the same deplorable condition that England has been

for so many years. It is our opinion that vivisection in pub-

lic schools should not exist. Laws in many states prohibit

that. There is a law covering that in the District of Colum-

bia. We have letters and a report from the commissioner

there that vivisection is not practised in the schools, and it

is not practised in the district schools anywhere, so far as

I can learn. We do not.want it, do not believe it humane

and do not wish to use the life of an animal unless it is fora

AMERICAN MICROSCOPICAL SOCIETY. 17

definite purpose. These remarks seem necessary to show

just the condition and the only way in which this bill can

be stopped. I think from reports that a large number

of senators and representatives who have committed them-

selves to it, show that the average man is interested in this

great question. The admission of such laws has cost England

millions of dollars. For example, two diseases have cost Eng-

land in money $400,000,000. The experiments necessary to

find out the causes of these diseases and to find out how these

diseases could be prevented would cost comparatively little.

Think of the number of animals that have died from these

diseases, to the amount in value of $400,000,000, and in this

country we had about the same thing going on until this

method was devised. All the diseases which have caused

innumerable millions of lives are now rare occurrences, such

as small-pox, cholera, and like diseases. It seems to me

the number of animals that have been sacrificed is very few.

On the other hand, I believe the animals used in these

experiments suffer inconsiderably. It is only a question of

premature death ; but the questfon, it seems to me, does not

rest on that. We have vivisection or animal experimenta-

tion for three legitimate purposes. The first is the demon-

stration of facts already known.

I believe it is necessary to experiment in medical schools.

I believe it is necessary, and think every physician in this

audience will agree with me, that every medical student

should perform experiments on animals. Nobody, in my

opinion, has a right to perform surgical operations on the

human body until he is familiar with these experiments on

the animal, which is always done with anesthetigs.

Then there is the necessity for experimentation for the

determination of facts, in which the knowledge to be gained

has not any immediate utilitarian value, but may be of untold

benefit ultimately. Some people think it is wrong to sacri-

fice life for this purpose.

Experiments made years ago determined facts that were

looked upon as ultra scientific that are now indispensable

18 PROCEEDINGS OF THE

to ourknowledge. Weare in possession of them because

those men experimented for fact’s sake and nothing else.

We make these experiments for the ultimate purpose of

determining facts which will save life and alleviate suffering.

There has been circulated recently, emanating from Phila-

delphia, a paper having a great deal of influence, saying that

there is not any such thing as rabies, and that as a specific

disease it does not exist. I do not know how many are

familiar with the Pasteur method, but I venture to give a

brief explanation of this. It was found by Pasteur and

many others that if rabbits or other animals are inoculated

with rabies they will die with certain paralytic symptoms.

Then if we inoculate rabbits with healthy brains they remain

well. Before this discovery by Pasteur, of people bitten by

mad dogs about 48 per cent. died. This has been reduced

by Pasteur’s treatment to less than I per cent. This disease

exists in this country to an enormous extent. We have

had in the city of Washington fifteen cases of rabid dogs

during the last ten months. One lady who was bitten by

her dog died of rabies. The period of inoculation in a rab-

bit is less than in a human being. This lady was bitten in

the face very badly, on the arm, shoulder and neck, by a

dog, and the dog was brought to us and I inoculated two

rabbits, and on the fifteenth day the physician who had charge

came to me saying, ‘‘she is showing signs of rabies.” We

examined the rabbits and they appeared perfectly well. She

died that night and the rabbits two days later. Again, a

lady brought a dog for examination, wrapped up in a blanket

on her arm, saying it had indigestion. I inoculated rabbits

and they developed rabies and died on the twelfth day.

I wish to make a motion that the president appoint a

committee from this society to draw up resolutions protesting

against this or any other bill prohibiting animal experimenta-

tion.

President—Before taking my seat I would like to say a

word about why this matter was brought out at this meeting.

Back of this movement is something that is very strong. Back

AMERICAN MICROSCOPICAL SOCIETY. 19

of this movement are money and influence, which are gaining

sympathy all over this country, towards the end of the preven-

tion of vivisection. It seems peculiarly strong, and it seems

to be very thorough. While most of us who received notices

have been in the habit of putting these circulars in the waste-

basket and smiling, the power behind has been methodi-

cal and industrious, and has been wasting no time. It is

pretty evident that its motive has been to take the citadel

and then gain the country. It looks as if this power intended

to capture the District of Columbia and then the country.

We have anenemy andastrong enemy. We should share this

interruption to our work with other scientific bodies ; and as

one of the bodies interested in this matter it would seem as

though we ought to do something, at least to show how we

stand on this subject, and for that reason the matter has been

introduced.

President—I believe there is a motion before the society

now to appoint a committee to draw up resolutions in this

matter. How many shall be on this committee, Dr. Moore?

Dr. V. A. Moore—I would suggest either five or seven.

President—The question is open for discussion.

Dr. A. A. Young—lIt seems to me three will express the

wishes of this society much better; I suggest a committee of

three be appointed to report tomorrow.

Dr. V. A. Moore—I suggested five or seven. I am notsure

that five is necessary. I simply thought that we have here a

society of ladies and gentlemen, and that it would be well to

have a committee comprising both.

President—Is there any discussion as to the matter

proper?

Those in favor of the motion that the president appoint a

committee to draw up resolutions to be présented tomorrow

please rise ; contrary the same. It is carried.*

This matter has been somewhat under advisement, and it

seems to the president and the executive committee that the

view taken by Dr. Moore is correct and that the president

20 PROCEEDINGS OF THE

will name as that committee Dr. V. A. Moore, the chairman,

and the other members, Professor D. S. Kellicott, Mrs. S. P.

Gage, Miss E. J. Claypole and Mr. H. von Schrenk. This

committee will kindly prepare suitable resolutions and report

to the society tomorrow.

The next paper, on The Acetylene Light as Applied to

Photo-micrography, with illustrations, was read by W. H.

Walmsley, of Chicago, III.

President—We will now listen to a paper by Dr. V. A.

Latham, of Chicago, Ill. The title is, What is the Best

Method of Teaching Micro-science in the Medical School ?

Discussion :

Professor S. H. Gage—I do not think this ought to

go without discussion. One thing impressed me very

much, and that was the order of studies. It is certainly a

very serious matter to have a person take up a subject he has

no preparation for; it is a pure waste of time and that can-

not be helped by the professor. We have in our own uni-

versity excellent plans. We say no student shall take this

course unless he has pre-requisites, for we say in the list of

our courses, a man may take a special course in microscopy

if he has had the preliminary course.

One point is not often recognised by teachers of science,

and that has reference to drawing, which might be omitted.

Most teachers of science will consider that heterodox, because

there is a kind of belief in the minds of teachers of science

that if a student only makes a drawing of his work then he

has some definite knowledge. I think Dr. Latham is entirely

right, that drawings amount to no more than a poor descrip-

tion made by the pupil. Ifthe drawing is considered with

great care by the teacher and the pupil can see that what he

put down came from his head, and not from the object, then

it is of value ; and whether, in my courses, it is worth while

for the pupil to draw everything I have my doubts and think

it is not desirable. I think they ought to be made to draw

in certain parts, but it ought to be of the same rigid kind

AMERICAN MICROSCOPICAL SOCIETY. AAA

and be criticised as severely as the examination paper, or the

pupil will learn to draw not from the object before him

but from his head. Some of the points in the paper are

very pertinent to teachers of science.

Professor E. W. Claypole—I quite agree with what the

writer says, also what Professor Gage has said. WhenI know,

as I do, the kind of material that is dumped into our medical

schools with the expectation that they in a short time will be

turned out M. D.’s, I am surprised that the teachers can do

anything with them at all. I have seen them go in and I

know how they come out. I think a great deal of responsi-

bility rests on those who teach in the medical schools, but in

the common schools they ought to learn things that would

be of use when they enter college or medical schools. Why

should they not learn drawing at school? It is the proper

place, and they have more time and ought to learn to use

their pencils with some degree of skill and draw from the

object before them. I remember a case where a student

brought me a beautiful botanical drawing. I gave the author

no credit for it and he wanted to know the reason. I said:

‘“You drew the flower from one, the leaf from another and

the stem from a third plant,” and he knew it and sat down.

President—I think that many points could be discussed,

but feel that we cannot discuss them for want of time.

I feel that the society appreciates what Dr. Walmsley has

done with his acetylene gas and with his suggestions about the

candle-power. It will be a pleasant thing for the society to

be associated with it ; and I canask, in the name of the society,

that Mr. Walmsley look into the matter and associate him-

self with some one he may select and perhaps another year

bring before the Society a new candle-power standard.

WEDNESDAY AFTERNOON.

The society assembled at the Casino at half-past two

o'clock and took the trolley cars, chartered by the local com-

mittee, for a trip to Homestead. Arriving at the Carnegie

22 PROCEEDINGS OF THE

armor plate works the members were met by officers of the

company and conducted through the various departments of

the immense plant. The return to Pittsburg was made at

five o'clock, and all were delighted and impressed with the

scenes often described, but rarely witnessed.

WEDNESDAY EVENING.

At half-past seven the members of the society and invited

guests from the city met in the lecture-room to inspect the

photo-micrographs, to witness the demonstration of acetylene

gas and to examine the microscopes, lantern slides and

microscopical apparatus.

The list of contributors to the photo-micrographical

exhibit included: Dr. R. L. Maddox, Southampton, Eng-

land;. Dr: Henri Van ,Heurck, Antwerp, Belem

Nachet, Paris, France; Mr. Andrew Pringle, London,

England; Mr. A. A. Carnell, Cornwall, England ; James B.

Shearer, Bay City, Mich. ; Dr. A. Clifford Mercer, Syracuse,

N. Y.; Thomas J. Bray, Warren, O. ; George Rafter, Roch-

ester, N. Y. ; J. B. Shearer, Bay City, Mich., andjothers:

Mr. Walmsley demonstrated the excellent qualities of the

acetylene gas by means of a lantern-slide exhibition, which

was thoroughly enjoyed by all present. The microscopical

exhibit was not as large as in former years, but was interest-

ing and profitable. Too late were received prints from T.

Comber, Esq., of Liverpool, England, and prints and lantern

slides from M. T. Monpillard, Paris, France. M. Nachet

sent, too late also, as a present to the society, a Daguerreo-

type made by Leon Foncault in 1844. He writes:

‘‘T have great pleasure to offer to the American Micro-

scopical Society a curious thing. Itis a Daguerreotype made

by Leon Foncault in 1844, and, what is most extraordinary,

I have proof that he began his experiments on this subject

three years before the date and signature engraved on the

corner of the silver plate (say, only one year after the publi-

cation of the invention of Daguerre) ; so that the application

of the process to microscopical photography followed imme-

AMERICAN MICROSCOPICAL SOCIETY. 23

diately the discovery of Daguerre. This Daguerreotype

with many others I have had the pleasure of owning for some

months, were made for the engravings of a very remarkable

work published in 1845 by Donné, the celebrated French

histologist, and it was the first atlas of microscopical histology

published after photographs. I hope this plate may have

some interest for members at the meeting.”

Ex-President Mercer is making an effort to retain the

photo-micrographs, which arrived too late, for exhibition

next year.

THURSDAY MORNING, August 20, 1896.

Meeting called to order at 10 o'clock.

The names of a number of new members were read, as

recommended by the executive committee, and by resolu-

tion the secretary cast the ballot of the society for them and

they were declared elected. They will be found in the list

of members at the end of the volume.

President—The first paper is by Mrs. S. P. Gage, on The

Development of the Brain in the Soft Shell Turtle.

Discusston :

Professor S. H. Gage—In connection with the brain of

sharks, if I interpret aright, the curvature is more in the adult

shark than in the earlier forms. In these the curvature is

more like the embryo than in the reptiles and amphibians,

which seem to me to have departed farther from the original

type. This is seen more in the embryological forms than in

the higher vertebrates and sharks.

Professor E. W. Claypole—We incline to the belief that

modern sharks have departed from the ancestral form, because

in the modern shark the whole front of the mouth and jaw

have been turned down to the under surface of the body.

The mouth is brought back away under the surface of the

head, so that the shark can see nothing unless he turns over,

because the mouth is on the under surface of the body, but

in the ancient sharks the mouth was not in that position. In

Japan the mouth is in front, in India the mouth is in front,

24 PROCEEDINGS OF THE

but most all have changed to bring the mouth to the under

side, and by the bending over of the brain and upper parts

of the head this has been brought about, but Ido not know

to what extent.

Professor D. S. Kellicott—It has been my privilege to

dissect the brains of the shark during the past year, and, of

course, the mouth of the shark was underneath, but the axis

of the brain was quite horizontal, as in the reptile.

Secretary—I wish to have the pleasure of complimenting

Mrs. Gage. Her work last year was very much appreciated

by the members and others. I am very glad to see she is

continuing this work and hope she will continue to do so for

many years to come. It seems to me that this saddle cleft

she has spoken about has enlarged to the crura; and, if that

is so, it seems to me that as the embryo develops, this space

getting shorter, it may have something to do with the motor

and sensory nerves going to the brain, because in the adult

that portion of the brain is quite well developed, whereas in

the embryo form it seems to be illy developed and the space

large.

President—The next paper is by Professor Kk. W. Clay-

pole, on The Teeth and Spines of some Fossil Fishes : Mazo-

dus and Ctenacanthus.

Discussion :

Professor S. H. Gage—lI used to read that the paleontolo-

gist, taking one of these teeth or spines, could reconstruct

the animal perfectly, so that it would be practically as though

the creature were before him. I was brought up on that

belief, but when I saw a paleontologist set the head of one on

the tail end of another and reconstruct an animal from half a

dozen teeth, I came to feel that paleontology was about as

uncertain as some of the modern studies and that paleontolo-

gists themselves are more amazed at the things which they

are supposed to make than those which they actually can

make.

Professor E. W. Claypole—We paleontologists are not the

AMERICAN MICROSCOPICAL SOCIETY. 25

only sinners in that respect. At the same time, there have

been some striking illustrations of what Professor Gage has

said. But that the paleontologist can reconstruct a fish from

its teeth is not true. If the tooth happens to be like that of

some other fish, then we can construct that fish, but if the

tooth differs from that of other fishes, we could not have

reconstructed it.

The next paper is by Professor D. S. Kellicott, of Colum-

bus, O., on The Rotifera of Sandusky Bay.

Discussion :

Professor S. H. Gage —Last year, when speaking of minute

forms in water, I had no conception of the little things we are

dependent upon. Taking life in the ocean, as whale, shark,

cat-fish and so on, that are of use to us, we have very little

conception of how they are possible. In a work like this on

the plankton of these waters, we are getting some kind of

notion how this life has a possibility of existence, and while

in a certain way it is more striking to the general public to

work on big things, I think finally it will be seen that the men

who are working on the small things are getting at the real

sources of knowledge and power. I suppose bacteriologists,

and others, were looked upon as those who had no connec-

tion with this world, but were derided. Those who worked

at bacteriology did some things that are of very great value

as also those who labor in other fields, and we think it a

great work for the community and all will ultimately under-

stand this. It seems to me the descriptions given this morn-

ing of these creatures are abundant in themselves for intel-

lectual enjoyment. The philosophic spirit is ground enough

for the study of these, even if the economic questions were

not involved. I study vertebrates almost altogether and not

these lower forms, and it gives me great pleasure to hear

about the other forms not familiar to me. The world’s

knowledge is so great that none can cover all of it, but if we

can gain help of friends working in other fields than our own,

it gives value to a society like this.

26 PROCEEDINGS OF THE

President—There follow two papers regarding water

supply. These two papers will be read this morning, the

first one by Dr. M. A. Veeder on Public Water Supply for

Small Towns, and the other by Dr. Wm. C. Krauss on The

Requisites of a Pure Water Supply, leaving the discussion

until afternoon.

THURSDAY AFTERNOON.

Meeting called to order at 3 o'clock.

Discussion of Drs. Veeder’s and Krauss’ papers :

Dr. Turnbull—The supply of water to cities and villages

is one of the most important of sanitary matters. It is a

question which is receiving a great deal of thought at the

present time, and a great many of the states are taking

individual action just at present. A few weeks ago I

was in Albany, N. Y., and got laws of the State Board of

Health, and found that outside of four or five cities, New

York, Brooklyn, Poughkeepsie, Albany and Buffalo, the state

board has entire control of this question. The law has not

been so active in cities, which are allowed to go on with the

present supply. Villagesand towns have to comply with the

requirements of the state board. The state board is really

the supervisor and the state engineer is really at the head.

No water works can be put in until the sanction of that board

is obtained ; that really gives the state the control of the

water supply, and likewise control of the sewage disposal and

control of rivers and streams.

Dr. Veeder said this morning that most cases of typhoid

fever occur in winter. I think they occur mostly in the fall.

The germs increase during the hot months of summer, multiply-

ing rapidly after a long period of incubation running from three

to four or five weeks. Germs take longest in September and

the disease reaches its height in the latter part of November.

When severe weather comes there is a drop, and we find by

the first or middle of January that the medium average for the

year has been reached. In January it is below, and in March

it is the lowest. As soon as warm weather comes on it

increases and gets to the average in August, reaching its

AMERICAN MICROSCOPICAL SOCIETY. 27,

climax in October or November. I have here a chart which

I compiled last year for Allegheny. I find that this chart

compared with the chart of London for the past twenty-two

years is almost identical. It is almost identical with that of

Berlin. The fever in the city of New York reaches its climax

in October or the latter part of September, showing that the

disease is generated mostly in the warm months and reaches

the climax before the cold weather starts.

Concerning filtration, I think that people generally

believe that filtration is new. They say, what are the

experiments in filtration, has it passed the experimental

stage? And it is very hard to get them to believe that

it has passed that experimental stage. It is perfectly

practicable and has been for years. We have preached

sanitary filtration here. Statistics for Allegheny and

Pittsburg show that we probably lead the civilised world

in the number of cases of typhoid. Allegheny leads Pitts-

burg. Last year in the city of Allegheny, with an estimated

population of 120,000, 1,764 cases of typhoid fever were

reported, and there were a great many unreported cases.

Several hospitals did not report their cases; a great many

cases acquired the fever here and were sent out of town

unreported. Probably the total number would run over 1,800,

or one case of typhoid to 69 of population. We have been

trying for years to get a good water supply, and have got

it finally so that the question is whether it is practicable.

The plan consists of having a filter or crib four feet below

the river bottom. The water runs through four feet of sand

and gravel, flows into the crib, and from there is pumped into

the reservoir. In other places below us, that has not been

successful; they have almost as much typhoid as they had

before. The only thing I can see where it would be of bene-

fit is that it would take out a great many impurities. We

get the water from about ten miles up the river. Ifthe plan

were carried out, the contamination would not be so great

and we would get better water, but how much better, time

alone will show, and I think, from all that I can hear, it is

28 PROCEEDINGS OF THE

not successful, and measures have been taken for buying

property and starting sanitary filtration. We are using the

water of the Allegheny and Monongahela rivers. There has

been an enormous death-rate for years. The State Board of

Health has no authority in the matter; we have not got that

far yet. Iam sorry that J have got to tell you these things,

you being visitors here, but I think these things should be

told. We need a new water supply and I am hopeful it will

come very soon.

Mr. W. H. Walmsley—I would like to say, in regard to

Dr. Veeder’s recommendation, that in Chicago we have

an unlimited water supply in Lake Michigan. For some

years the water had been taken from cribs, by means of

tunnels. At that time there was very little pollution in

the lake, but as the city grew we found it necessary to

extend these tunnels. In 1893, a crib four miles out from

shore was finished. We now find that when the wind

blows from the south or southwest the water is carried

toward and into the outer crib, and whenever it is found even

in the slightest degree polluted, the warning cry comes, to

‘Boil the water.” But, after all, I believe in cases where

the contamination of water is even suspected, the best way

is to boil the water and thus purify it from disease, especially

typhoid fever.

Dr. A. M. Bleile—lIt is pretty well agreed that chemical

examination of water has very little value except as to its

hardness. I am almost prepared to believe, after a some-

what extended experience, that the bacteriological examina-

tion is unreliable, at least in this sense, and wish to urge

this, in order to do away with the false sense of security, of

the harmlessness of bacteria. That such water later breeds

disease has been demonstrated more than once. The only

thing is to watch the surroundings, and the engineer is bet-

ter to do this than the bacteriologist. Unless examina-

tions are made daily they have little practical value. After

the germ is discovered, generally the mischief has been done.

For instance, an outbreak of typhoid occurred in a hospital

AMERICAN MICROSCOPICAL SOCIETY. 29

with which Iwasconnected. Thesupply of water comes from

reservoirs and during the day is used from wells. This water

was examined by others and myself, and found to be very good.

There was suddenly a case of typhoid fever. The patient was

put into cottage6. Twoweeks after her admittance into cot-

tage 6 a case broke out ; a week later, another ; in all, nine

cases in that cottage. The cases were all confined tocottage

6. Now, these patients got the same food as the others.

We investigated the dairy that furnished the milk; no typhoid

about that, it being well kept. The ice used is artificial,

alleged to be, but I doubt this. At any rate, there was

nothing at all that we could find as giving origin to the con-

tagion, and none of the 450 other patients, who had precisely

the same supply as these, had developed a single case. I can

not explain it. I firmly believe typhoid is water-born, or

milk-born when water gets into the milk. We found nothing

in water or milk. I believe some germs came into the uten-

sils there at some time. Things are as nearly perfect as

possible in such an institution. One explanation would be

that typhoid fever is a contagious disease, but all evidence is

against that, but I would judge from this case alone that it

is contagious. But the point is, that at some time germs

were introduced into the water, probably in the reservoir,

had existed there for a little while and then died out. The

town below now shows typhoid fever, although pure water

exists there.

President—This will have to end the discussion, as far as

others are concerned, but Dr. Veeder will please answer.

Dr. M. A. Veeder—The point in regard to typhoid fever

in winter is not about the number of cases, but such cases as

do appear—where they do occur they are more severe—that

is the point I make. In reference to boiling water, I might

say I mentioned that—I have been recommeding so doing for

years. My plan is simple and successful—boil the water and

have a large stone jar, fill it up and allow sediment to deposit

in stone crock and in most localities there will be a large

deposit of lime. Then the direct method would be to have

30 PROCEEDINGS OF THE

in the house for that purpose, a large number of fruit jars or

tight water bottles and put the water in them; if not having

ice put them onthe cellar floor. People tasting this water will

notice that it is clean and is much better than by using filters,

which get foul and are not known how to be kept clean.

President—There has been one paper crowded out and

only one, the author of which is here, Mr. Hermann von

Schrenk. I think that he will be glad to give us some little

account of his paper, occupying about five minutes, and then

our program will be quite complete.

The secretary then read by title the remaining papers,

being by members who have not been present :

Some Methods of Histological Technique, etc., by Dr.

J. Melvin Lamb, of Washington, D. C.

Study of the Cellular Pathology of Carcinomas, by Dr.

Clifford Walcott Kellogg, of New Haven, Conn.

Red Corpuscles in Legal Medicine, by Dr. Mosesn@:

White, of New Haven, Conn.

Study of the Colorless Blood Corpuscles, etc., by Dr.

M. L. Holbrook, of New York City.

Increasing Pollution of our Municipal Water Supply, by

Dr. F. J. Thornbury, of Buffalo, N. Y.

Historical Diphtheria; its Bacteriology, by “Dm Gan

Craig, of Danbury, Conn.

Historical Note on Photo-micrography, by Dr. A. Clifford

Mercer, Syracuse, N. Y.

This completes the list, Mr. President.

President—We are now under head of ordinary business.

Secretary—lI wish to say that all members who have read

papers and have not handed them in will do so as soon as

possible, as I wish to have the transactions out about the Ist

of December, if possible, and surely before the holidays

(applause), and if our president will set the example all will

go well. If the transactions are delayed it will not be the

fault of the secretary but of the members of the society.

President—Have you any other report ?

AMERICAN MICROSCOPICAL SOCIETY. 31

Mr. M. Plaum—There are two special committee reports.

At the last meeting of the society a special committee of

three was appointed to re-invest the Spencer fund.

To the American Microscopical Soctety +

The undersigned, a committee appointed at a meeting at Ithaca, to

re-invest the Spencer-Tolles Fund, respectfully report :

After considering the question of receiving but ordinary savings bank

interest at 4 per cent. and perhaps 14 per cent. per annum from a building and

loan association, they decided unanimously in favor of the latter. A proposi-

tion was received from the Keystone State Building and Loan Association, of

Pittsburg, showing that an investment of $400, if made before January I,

1896, would in four and one-half years mature and yield the sum of $700, and

thus would earn an average yearly interest of 16.66 per cent. The officers of

the Association being personally known to your committee as men of honor-

able standing and of excellent business experience the committee unhesitat-

ingly authorised the investment of the fund in said Association. The only

care remaining to be exercised was to bring the fund up to $400, and to lose

no interest in the transfer from Urbana, Ohio, to Pittsburg. The fund at the

Ithaca meeting amounted to $372.27; the transfer was so made that full

interest was received from the old investment up to January I, 1896, bringing

the sum up to $391.63, to which a contribution was made of $8.37, making

the full $400, which began to earn interest from January I, 1896.

We hope that results will prove that our judgment in this matter was not

faulty. Respectfully submitted,

MAGNUS PFLAUM,

CG MEEEOR

C. G. MILNOR.

President—This report is before you; what will you do

with it ?

It was moved and seconded that the report be adopted

and the committee discharged.

President—The fund will remain in the treasurer’s hands

after the discharge of the committee.

The motion was carried and the committee discharged.

Mr. M. Pflaum—-The committee appointed at the last

meeting reports as to the property of the society as follows :

To the American Microscopical Society -

The undersigned committee, appointed at the last meeting, to investigate

the matter of the property and of a permanent home for the society respect-

fully reports :

I. That this society should adopt as a principle to gather no property of

any kind, and to dispose of what it has on hand at the earliest opportunity.

32 PROCEEDINGS OF THE

2. That, until such disposal, the property now on hand should neces-

sarily remain stored at Pittsburg, the residence of the present custodian.

3. That as long as the society owns property it should, for the necessary

convenience of the custodian, be under his direct control and be stored at his

residence—a permanent storage place being, although for some reasons desir-

able, entirely impracticable.

Second, as to a permanent meeting place, this subject is one fraught with

difficulty, and a very serious matter to determine.

A custom cannot be changed ina day. For nineteen years this society,

wherever it met, has been guests and been treated as such. And there

is no doubt the cities and the local membership therein, as well as the society

enjoyed the meetings the more because of this relation of host and

guests. Should now this custom be changed? Were the society to have

a regular meeting place, then, the glamor of entertaining and of being

entertained will vanish, and the society, perhaps, be the loser of many mem-

bers on that account. The meetings will become dry and business-like and

Jack that spirit of ‘enjoying a vacation” which no doubt has aided in bringing

many members to the meetings who would otherwise not have attended.

Although the society contains many members who are animated solely by the

love of science and do not care for the embellishments usually attending our

meetings, yet it must not be forgotten that the society is still a missionary

body, endeavoring to make converts and must use popular methods in its

work.

The expenses of the meeting have always been borne by the local com-

mittee, aided by generous citizens. This will, of course, not be the case if

the society settles as a permanent resident of a place.

From these points of view your committee cannot recommend a change of

the present itinerating method of annual meetings.

The society has never as yet been without invitations from places where to

meet, and we may safely trust the future to furnish the same hospitality as

the past. But should it happen that no host offers himself, our executive

committee may be depended upon to find one.

Respectfully submitted,

MAGNUS PFLAUM,

C. C. MELELOR,

C. G. MILNOR.

President—What will you do with the report of the com-

mittee? If it is moved to receive it, you can consider it

later.

It was moved that the report of committee be received

and that the spirit of the report be accepted and adopted.

Seconded.

Professor D. S. Kellicott—I do not want to discuss this

question with a spirit of opposition, but the first part of the

AMERICAN MICROSCOPICAL SOCIETY. 33

report, the part which refers to custodian of property, I must

say, does not commend itself to me. I can easily see

how conditions may arise in which our property may be

kept and administered without undue tax on the time and

patience of some member of the society, and think I can see

that our property with the volumes, if fragmentary, are worth

holding for some time. Papers may be called for, and if the

volumes are dispersed, are lost. I think it will be well to con-

sider the question a little farther and give it more time, and

see if it cannot be solved. It seems to me that would

be better. It is not necessary that the treasurer should be

the custodian ; it is not necessary that the custodian should

live in the same place with the treasurer. I feel, however,

that there should be a permanent custodian, one who has

a garret at his disposal and who could store the property.

I really think it would be better than to dispose of our

property.

The second part of the report, in regard to permanent

place of meeting, I heartily agree with and will be glad to

vote for. The'country is too broad, too large, to have a

single meeting place at the present, so I would really wish to

have the question divided ; that would be my desire, however

the society may feel differently.

President—Will the mover allow this to be divided? If

the second has no objection we will consider it divided.

Now we will take up the first part of the question, the receiv-

ing of the report, and then we can take some action upon it

afterward.

It was moved that the report be received. Carried.

A motion was made to adopt the second part of the

report. ~ Carried.

President—What will you do with the first part of the

report ?

Professor D. S. Kellicott—I will make the motion to lay

the question on the table. Seconded.

34 PROCEEDINGS OF (THE

President—That will leave it open for discussion another

year.

Professor D. S. Kellicott—We will then be one year older

and wiser. - We may have a good building and a cellar and

a garret by that time. I may move to make Dr. Bleile the

custodian another year.

The motion to lay on the table was carried.

President—There is a little business left over from last

year. For instance, announcement was made at our last

meeting that it would be desirable to make a change in the

constitution, in Article II., so as to read:

Any person interested in microscopical science may become a member of

this society upon written application and recommendation by two members

and election by the executive committee.

Professor D. S. Kellicott—I move to adopt the amend-

ment as now presented. Seconded.

Dr. A. A. Young—I would like to know the names before-

hand of those who are getting in before they are acted upon

by the executive committee.

President—lI believe it is good policy at every step to get

rid of business in our meetings and keep ourselves to papers.

I think this amendment will aid us.

Dr. A. A. Young—lIf objection is had to a candidate,

could not I have it in my power to make objection? By this

means I could not.

-Professor S. H. Gage—Our method was patterned after

the American Association for the Advancement of Science.

They elect by executive council, and there has never been

any abuse. These men are all tested by two members of the

society, who vouch for them under doubtful circumstances,

and I rather think that Dr. Young overestimates the danger

of getting the wrong people in. Ido not think this is the

kind of society the wrong people would get in. If it were

‘©The 400” it might happen.

Mr. W. H. Walmsley—I know that this method was tried

in several instances. I know that when names were read out

AMERICAN MICROSCOPICAL SOCIETY. 35

it was the habit of no one to make objections; and in that

way cranks were admitted. But when handled in com-

mittee cranks were sifted out.

President—We will have a standing two-thirds vote.

Carried. The amendment is adopted.

President—Then there are some changes necessary in the

by-laws. You will notice in your last copy of the constitu-

tion our old name still appears. That is simply a mistake

and will be corrected without action ; that is in section five.

If the secretary will read By-law II. you will see necessity

for another change.

Secretary reads :

The secretary shall edit and publish the papers accepted, with the neces-

sary illustrations, in four numbers. The first number to be issued not later

than October I, after the meeting, and the remaining three numbers at inter-

vals of not more than three months.

President—What will you do with this? I believe this

was brought up a year ago. A resolution was passed by the

society to the effect that the Proceedings be published in one

volume instead of four, but no corresponding change was

made in the By-laws. It remains for someone to move that

the By-laws be changed to correspond.

It was moved and seconded that this change be made.

Carried.

President—The third section of the By-laws needs some

attention.

Secretary reads :

The number of copies of Proceedings of any meeting shall be decided at

that meeting. Each author of papers accepted and published shall be entitled

to twenty-five separates of his paper and as many more at the cost of publish-

ing as he may request at the time that his manuscript is sent to the secretary.

Last year I had a great deal of trouble in getting twenty-

five extra reprints for contributors, costing $75.00; and much

trouble and worry to have reprints sent out, and in one

instance the reprints never arrived at their destination. I

propose, if the society is willing, to cut off extra reprints to

members, at least for one or two years, to save expense.

36 PROCEEDINGS OF THE

A motion was made and seconded that this section of

the By-laws be remodeled or altered by leaving in simply the

first sentence, the rest to be stricken out. Carried.

President—The secretary asks me to call attention to sec-

tion Vi; - ikends”:

Papers accepted for publication by the society shall not be published else-

where until after they have appeared in the Proceedings of the society, except

by consent of the executive committee.

Professor D. S. Kellicott—That was really rescinded years

ago. Whether it got into print or not I cannot say, but my

recollection is that the whole thing was rescinded while I

was still secretary.

President—By oversight I was led to suppose that the

election of officers could take place at any time, but it

appears it should take place in the morning. But it seemed

wiser to finish up all our papers and then have exclusively a

business meeting. We will finish our general business and

then proceed to the election of officers. Now is a suitable

time to decide as to the number of copies of the Proceedings

you will have for next year.

Secretary—I would rather the matter be left to the secre-

tary and the treasurer. If there is not much saving let us

get out the 500, but if there is let us get out only 400 copies.

President—lI think it would be wise to leave this matter to

these officers with discretion.

President—It is moved, by Professor Kellicott, and

seconded that we publish 400 copies or more, according to

the discretion of the secretary and treasurer. Carried.

President—I find on our records another suggestion of

change in the Constitution, notice of which was given last

year.

Secretary—It was moved last year by the secretary—a

proposition submitted—that there be two conditions of mem-

bership for life, to add to our income. . Reads:

A proposition has been submitted that there be two classes of members, or

two conditions of membership for life, which would add to our income. The

AMERICAN MICROSCOPICAL SOCIETY. WON,

first is that persons or organisations ‘desiring to obtain the Proceedings, by

paying $50 would be considered as subscribing members, without any other

rights of membership; while those paying $100 would be full life members,

and entitled to take part in the proceedings of the society.

This is submitted as an amendment to the Constitution.

President—There is a notice before us of an amendment

to the Constitution. What wiil you do with this motion ?

Will you take any action or not on the matter? Shall we

have life memberships of two characters, one to cost $50,

one $100, one to have Transactions and nothing more, and

the other to have Transactions and privileges of meetings?

If there is no motion we will consider that nothing is to be

done with the question. Thereseemsto be nomotion. The

matter will be dropped.

President—In regard to the printing of the Proceedings

there seems to be another point about which we have a sug-

gestion. It may be possible to make a reduction of expense

by not printing the Constitution and By-laws separately.

Last year the society passed a resolution to the opposite

effect, saying that our secretary should print separately our

Constitution and By-laws. If there is no objection the reso-

lution will stand and the secretary will print separate copies.

Secretary—The price for printing the separate reprints

was $15.00.

President—A motion to rescind the resolution of last year

would simplify matters.

It was moved and seconded that the resolution of last

year, authorising the secretary to print separately the Consti-

tution and By-laws, be rescinded. Carr‘ed.

President—We have some committees to report, one on

the vivisection matter, of which I believe Dr. Moore ts chair-

man.* Dr. Moore.

Dr. V. A. Moore—I have here a few copies of :papers

received this morning, in which this bill is analysed and

the effect it will have on the animal industry of the country

set forth.

38 PROCEEDINGS OF THE

I furthermore desire to ask each member to write to the

chairman of the District committee, or to the presiding officer

of the Senate, protesting against the bill; also letters to the

senators and representatives of his state. I think short letters,

to the point, by different members of this society, will do a

great deal of good in bringing about a just consideration of

this bill. The committee desire to submit the following

report:

WueErEAS, The American Microscopical Society, assembled in Pittsburg:

Pa., August 18, 1896, for its nineteenth annual meeting, recognises the fact

that the development of biological and medical sciences has resulted largely

from experiments upon living animals ; and

WuerEAS, Those engaged in experimenting upon living animals in scientific

laboratories do so for the purpose of gaining the knowledge which may result

in alleviating human suffering and improving the condition and value of domes-

ticated animals ; and

WHEREAS, No evidence has been presented by those who advocate restric-

tive legislation showing that abuses, such as cruel and unnecessary experi-

ments, are practised in the District of Columbia ; and

WueEreEas, Results of great scientinc and practical importance have been

obtained by experiments on the lower animals made in Government laboratories

in the District of Columbia; therefore be it

Resolved, That the American Microscopical Society earnestly protests

against the passage of Senate Bill No. 1552, entitled, A Bill for the Further

Prevention of Cruelty to Animals in the District of Columbia, or any modifi-

cation of this bill, or of any other bill restricting animal experimentation for

scientific purposes.

Resolved, That copies of these resolutions, attested by the signatures of

the officers of this society, and of its committee appointed to draft these reso-

lutions, be sent to the chairman of the committee on the District of Columbia

in the. United States Senate and House of Representatives.

(Signed) A. CLIFFORD MERCER, President.

WM. C. KRAUSS, Secretary.

MAGNUS PFLAUM, 7vreasurer.

V. A. MOORE, Ithaca, N. Y., Chazvman.

Da S. KELLICOLT seolumbus. 0:

SUSANNA PHELPS GAGE, Ithaca, N. Y.

EDITH J. CLAYPOLE, Wellesley, Mass.

HERMAN von SCHRENK, St. Louis, Mo.

President—The report of the committee is before you;

what will you do with it?

It is moved and seconded that it be received and adopted

AMERICAN MICROSCOPICAL SOCIETY. 39

by arising vote. Isthere any discussion or word to be said ?

Carried unanimously.

Professor D. S. Kellicott—It seems that those connected

with public institutions would have much influence in this

matter, and if we see that those institutions take a hand in

it, it may have some value. I think it will be well to have

the resolutions printed.

Dr. V. A. Moore—lIt is of great importance to bring this

matter to the attention of different members of Congress.

I have already seen the representative who represents my

district in Congress, and he is heartily opposed to any such

legislation. I think it would be wise to have some one see

personally those who represent each member of this society

in Washington—in addition to what may be done by institu-

tions.

President—The executive committee has seen fit, under

our Constitution, I believe, to recommend to this society

the election of honorary members. As your president

is somewhat responsible for this action by the executive

committee, he would like to say a word or two about it.

One candidate was our first president ; he was also our sec-

ond president. He has always been in harness up to very

recently ; but with advancing years his vacation becomes a

matter of importance to him, and it is doubtful whether we

shall see very much more of him in active meetings. His

interest continues. You had a letter from him in which he

excuses himself on those grounds. Ireferto Dr. R. H. Ward,

ore roy, N. Y.

The second candidate was our third president, Professor

H. L. Smith, of Geneva, N. Y., and he was our president

twice, as was Dr. Ward. He was in the harness until illness

and death in his family brought life almost to an end with

him. A letter from him is encouraging, indicating he is

likely to be with us again before long.

The third is Dr. Maddox, of England. He has sent to this

meeting photo-micrographs taken by himself many years ago.

40 PROCEEDINGS OF THE

He is the Nestor of photo-micrographers and the discoverer

of the present dry plates used in photography.

Professor S. H. Gage—I have the honor to move that

General J. D. Cox, of Cincinnati, O., be also made an honor-

ary member. I think the older members of the society

recognise that we have in him a man who commands respect

as a microscopist as well as statesman and historian and that

we honor ourselves by electing him an honorary member. I

will move that we add his name to the list of honorary mem-

bers. Seconded.

Mr. M. Pflaum—I move that the secretary cast a ballot

for the election of these members as honorary members of

this society. Seconded. Carried unanimously. .

President—Unless somebody has a reminder for me, it

only remains for us to receive and act upon the report of the

nominating committee. The nominations are:

For president, Professor E. W. Claypole, Akron, Ohio;

for vice-presidents, Mr. C. C; Mellor, Pittsburg, Pa.) ere

M. Bleile, Columbus, O. ; for members of the executive com-

mittee, Dr. A. A. Young, Newark, N. Y., Mrs: Susanna

Phelps Gage, Ithaca, N. Y., Dr. Wesley P. Manton, Detroit,

Mich.

A motion was made that the report be received, committee

discharged and secretary cast a ballot of the society for the

election of these officers for the coming year. Carried.

President-—The secretary has cast a favorable vote for

these officers and they are our officers for the ensuing year.

Applause.

Professor Gage—lIt is one of our great pleasures always at ~

the close of the meetings to open our hearts a little, as the

hearts of the people were opened to receive us when we came

to the place of meeting, and it is with peculiar pleasure that

I shall try to express, as well as I can, our feeling toward the

local committee of Pittsburg. Every one who has had to do

with the carrying on of the meetings realises after he has had

this experience that there is a great deal to be done; and

AMERICAN MICROSCOPICAL SOCIETY. 41

every one connected with the society knows that a great deal

of the success of the meetings depends on the way the local

committee has smoothed the road, the doors and windows

oiled and machinery moving so that everything is ready for

us. I have been to a good many meetings of this society

and always with great pleasure, with one or two exceptions,

when we have had too much politics and am glad to say that

we have not had any this year. Never have I been to one that

has been better managed than this one. An extra good kind

of oil has been put on doors and everything done to make our

meeting successful as a scientific meeting. Everything pos-

sible has been done to give us that intellectual pleasure and

enjoyment which is so great a part of a meeting of this kind.

And, therefore, Mr. President, it is with peculiar pleasure

that I move a vote of thanks to our local committee for mak-

ing it possible for our meeting to be so successful.

President—It is moved and seconded that this society

extend its thanks to the local committee for its great kindness,

for its abundant work and the pleasure that the committee has

given the society in many ways. Carried unanimously. The

committee is therefore thanked with the full heart of this

society for its work in the direction named.

What is the further pleasure of this meeting ?

Miss E. J. Claypole—I am sure that everybody who has

attended the meetings appreciates the fact that much depends

on where they are held; and it gives me a great deal of pleasure

to speak of the way in which we have had the opportunity of

using this beautiful building and the hospitality shown to us

by the Librarian, Mr. Anderson, and the Superintendent, Mr.

Cunningham. I do not think that any student goes througha

library or building like this without appreciation, and there-

fore, if it is in order, I would like to move a vote of thanks to

‘these two gentlemen. Seconded. Carried.

Secretary—I move to extend a vote of thanks to the

officials who were instrumental in permitting us to see the

Carnegie Iron Works, on the afternoon of the second day, and

42 PROCEEDINGS OF THE

also to Mr. Mellor a special vote of thanks for his interesting

recital on the first day.

President—As a sort of general expression let this be a

rising vote. Carried unanimously, and it is hearty I am sure.

Miss Claypole moved a word of appreciation to the superin-

tendent of parks for flowers, which was seconded and carried.

Secretary—Last, but not least, we have to thank the press

of this city for the able way in which they have treated us.

Nearly every paper had one-half to a column or two col-

umns about our meetings. I was told that it was unusual

for the press to extend that kind of hospitality to such a

small society, and I think it would be well to give a vote

of thanks to the press for their kind treatment of the Micro-

scopical Society. Seconded.

President—Carried, and our thanks will be extended in the

proper way to the press. The secretary wil) attend to that.

President—Is there any further general business to bring

before the society? If not, the time has come when my

relation to you as president ends. I can assure you that,

although it has caused me work, I have enjoyed every moment

I have served you in this capacity. I have learned to feel

more than ever before that I believe in the society. I see

reasons for its existence, and I am pleased to work for it. I

think that must be the feeling of every officer who under-

takes the work connected with this society. As the work

progresses the reasons for the existence of such a society

become more and more evident. The letter, which per-

haps you have read, the letter which I sent to all of you,

has expressed some of these reasons, which I need not now

repeat. I believe that there is a need for this society and

that there is important work for it to do.

I thank you for your kind attention throughout the meet-

ings. I feel grateful to my fellow-officers who have done

so much of the work, and, of course, I feel particularly grate-

ful to the local committee and especially to the energetic

AMERICAN MICROSCOPICAL SOCIETY. 4

gentlemen who represented that local committee. I know

they have suffered the pangs of discouragement, and I hope

they have now grown out of that despondent condition and

feel happier, beause they must realise they have made this

meeting a great success.

I again thank you ; and take the greatest kind of pleasure

in asking Professor E. W. Claypole to relieve me of farther

duty.

Professor E. W. Claypole—I have not much to say this

afternoon ; my turn has not yet come. I thank you heartily

for the quite unexpected honor conferred upon me, and I feel

that it will be quite a responsibility, and I shall have

to rely on your kind help in a great many ways in order to

accomplish results next year. But, relying on you, we will

promise to do our best at the next meeting and during the

interval to further the interests of the society in any way it

is possible. I own that I do not share the opinion that has

been sometimes expressed, that this society has no true

reason for its existence, for there is enough room, scope and

work for a microscopical society between the Atlantic and

Pacific, and the Canadian and the Mexican line. I do not

know where a microscopical society could not find space in

this sphere. There are subjects of which we know nothing.

There are men and women who are able to investigate, whose

attention has not yet been turned this way. We want to

turn the thoughts and attention of students to fields where

microscopical investigation lies. We want the help of prac-

tical students to help students who cannot afford to give time

ormoney. If the Royal Microscopical Society of England can

do its work and retain its position in that small country where

work has been going on for ages before it began here, we see no

reason why there should not be good, full and ample scope on

this side, where the harvest is plenteous and laborers few.

Railways will not give us as great advantages as we wish they

would ; the consequence is that the workers are scant, but

the bond that unites the members of this society should be

sufficient, if they are really workers, to keep them in line

A4 PROCEEDINGS OF THE

and on the track of work. If I had time I could say some

things in regard to methods that could be used to strengthen

the society, but will conclude by saying that it will be my

effort to serve you to the best of my ability during the year

we are now entering.

Professor D. S. Kellicott—Our late president has now

retired to the position of an ordinary member, and I suppose

we may look upon him and speak to him and address him in

the ordinary tones and manners. I suppose also, knowing

him as I do, that he is a gentleman who would care to have

our opinion of his work and opinion of him as a gentleman.

I wish to move the high sense of regard in which we have

held him as a presiding officer of this society during the past

year.

I move that the society express its regard in a resolution.

Seconded.

President— You have heard the motion put and seconded.

Those in favor signify the same by rising. Carried.

Mr. M. Pflaum—I wish, on the part of the local commit- .

tee, to extend an invitation to the society to attend a

theater party this evening. We know the sublime is often

closely connected with the ridiculous, and we thought you

might enjoy a highly moral minstrel show. First, the place

where this performance is to take place is ina theater. We

will all start together from the Monongahela House ; after the

theater, please stick to the local committee and we will lead

you on in satisfactory ways.

Dr. A. C. Mercer—We have finished all our thanks and

here this thing comes on—what are we going to do about it?

I move we accept this very kind invitation from the local

committee and thank them for another evidence of great

kindness, consideration and forethought.

Seconded. Carried. P

Dr. A. C. Mercer—Another matter ought to come up

here. Some who have known of work going on through the

year are aware that certain journals have done a great deal

AMERICAN MICROSCOPICAL SOCIETY. 45

for the society, particularly two—the Odserver, of which

Miss Booth, one of our members, is the microscopical editor,

and Mr. Smiley, of Washington, has given us a full page in

the Microscopical Journal throughout the year. Letters have

passed between Mr. Smiley and members of the executive

committee and we have reason to feelthat he has done a great

deal for the society in getting membership and, therefore,

I would move we extend our thanks to Miss Booth and others

connected with the Oédserver and to Mr. Smiley for the help

they have given us through the year. Seconded. Carried.

The society was then declared adjourned.

Thursday evening was pleasantly spent at a theater party,

to the enjoyment of all who had the good fortune to remain,

and thus ended, perhaps the most successful and certainly

the most enjoyable meeting the association has ever held.

460

PROCEEDINGS OF THE

‘TREASURER’S REPORT.

FOR YEAR ENDING AUGUST 12, 1896.

Balance on hand at Ithaca meeting, Brooklyn Prize

fund ..

General fund... .

Membership dues, 1893, 1

sa ie SOAw On.

nC (OPIS OS sero: - :

Hs ‘* 1896, 224, less $1.04 .

re oe SO7, PUL IZ

.s for meeting only .

Admission fees, 1895, I

a “SE EISGOn 20) -.

i. aE ANSO7 ee

Donation ..

Exchange

Sale of Proceedings . . :

Contribution Brooklyn Prize find os

- International Bibliographical Bureau

Spencer-Tolles fund. .

, Postage

Expressage .

‘ Stationery and printing .. .

Sundriesjover +e Be Poe ct cic a owes

Issuing Part 4, Vol. XVI.

a Vol: XWik

‘ Brooklyn prizes ..

International Biblioetaphical’ Buen 5%

‘ Investment Spencer-Tolles fund

Balance on hand. .

$30.00

66.92

2.00

16.00

36.00

446.96

23 00

1.00

3.00

78.00

6.00

5.00

51.00

25.00

$96.92

524.96

87.00

5.25

99.93

76.00

400.00

$1,281.06

$35.75

45.53

34.90

31.95

123.43

478.50

81.00

25.00

400 00

$1,256.06

25.00

$1,281 06

AMERICAN MICROSCOPICAL SOCIETY. 47

SPENCER-TOLLES FUND.

slLopAmount reported at) Ithaca meeting. 3 5 - = 21. 4... « $372.72

‘« Interest to January I, 1896 Be ED) nD coos sige. thls sleet cet Ig. 61

“ (Clovatiell ornincwl oye Wilevess ebeyeten 6 GG 5 Gh. of 5 6 GO oo 8.37

400.25

IWESSTEXPONSES ihc ce (ae versal s!) oe) NeaRseMC REN ESEE yon Tes acy Leer 25

400.00

soplnterest toa)iily. I; SOG! i. |. ae ciate Wome eee) esis, fo eset etiire 23.04

423.04

Motalsincrease during! yearucy en yen ees oe ee ee 50.77

MAGNUS PFLAUM,

Treasurer.

We hereby certify that we have examined the foregoing accounts for the

year 1895-1896, and find the same correct with proper vouchers for expendi-

tures.

August 18, 1896.

F. W. KUEHNE,

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NOTES ON COMPARATIVE HISTOLOGY OF BLOOD

AND MUSCLE.

EDITH J. CLAYPOLE, Pu. B., M. S., WELLESLEY COLLEGE,

WELLESLEY, Mass.

The difficulty of basing general histology on books and

discussions of human histology must have presented itself to

anyone who has attempted to do it. Since almost all the

standard reference books on the subject are written from a

medical point of view for medical students the gap between

standard books and the materials used becomes quite wide.

Even if any mammal other than man is made the object of

study, there is trouble since many of the tissues of the cat

and rabbit, for instance, vary widely from the same tissues in

man, while if any of the lower forms are used still greater

differences are present. Compound tissues, in particular,

differ, many layers well recognised in human tissues being

absent or poorly developed. Many of the elementary tissues

also are markedly different in the various animal forms.

These points led me to examine some of the tissues of a

few of ourcommon animals to find the differences present,

and if possible some explanation of them.

The animals chosen were the rabbit, cat, pigeon, turtle,

snake, frog (Rana viridis), Amblystoma, Cryptobranchus

Necturus, and also, to a slight extent, Amia a Ganoid fish,

and Protopterus a Dipnoan.

The results are necessarily limited and somewhat incom-

plete, only two tissues being examined thoroughly.

Llood and Striped Muscle.—Some others are partly worked

out, but not fully enough for discussion.

Blood, a tissue in form, if not in function, has received a

very large share of attention, greatly owing to its medical

50 DAD BSO Py Le IG WA O NUIT; =

and legal importance. Interest has always been centered on

the size and number of the red corpuscles, a structure, so far

as known, peculiar to vertebrates.

The corpuscles of all animals fall into two natural groups,

those with nuclei and those without; these almost agree,

with a division on the basis of shape, oval and circular, with

but one exception, on each side. All mammals, so far as

known, possess normally non-nucleated, biconcave, circular

red corpuscles, with the exception of the camel tribe, which

has oval cells. All other vertebrates—birds, reptiles, amphi-

bians and fishes—possess nucleated oval corpuscles, with also

one exception; the lampreys (cyclostomes) have circular

nucleated corpuscles.

I have either made or collected from various sources

measurements of the red blood corpuscles of as many forms

in these classes as possible, with the following results placed

in the form of a table.

Drawings were made from fresh preparations of Ama,

snake, pigeon, frog, Cryptobranchus, Necturus, lamprey and

man. The drawing of Amphiuma was made from preserved

material. (Plate I.)

COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE.

SIZES OF CORPUSCLES.

Oval. |

Authority. | Circular.

Ee B.

FISHES : u UL 7

Teleost - Watts (ss ped Ome oN SF

Carp Aerial wean 9 Brass. Mammals. .. 6.5

Teleosts in general) 18.1 | 11.4 Frey. |Lamprey Eel..12.6 E. J. C.

Ganotd : Cyclostomes . 11.3

Sturgeon <7. 2.) 13 10 | Welcker. |

Amia PG) |) 8:6 pie aul

Llasmobranchii -

Ray and shark. { 5 Frey.

Dipnoan :

Lepidosiren . 41 zg | Welcker. |

AMPHIBIANS :

scaly. . 18.2 15 Frey.

POP ye0 (yr ys) « 22.2) ||: 1635 eB aefC eso

sRoadan ts. =: ett \Laod 16 | E.J.C.

: fe. 25 16 | Brass.

Triton aS ea Frey.

Megalobatrachus..| 47 33 Brass.

Cryptobranchus . .| 48.7 | 29.2 | E. J. C.

WEEMS sens 2 | SO 4"h srr | EJ. CE:

IPEOLEMS = = 2h | 58 35 | Brass.

Siren . 59 30 | Vailians.

Amphiuma 75 45 JEP ak Oy

REPTILES :

pa Tle seigest ls er ees 15 6 Brass.

Snake Sie | Teo | gids jae

2 i) 16 10

Lizard Slilkets ro Brass.

Alligator ea) 20 7 LE dof.

BrrDs :

Fowl. . 12 i Brass

Pigeon . 12 7 135. jie

MamMMAL:

Camel. . 8 4

These figures are very significant and suggestive.

ation ranges from 6 #. to 75 wu.

class ‘‘fishes” there is marked difference.

Among the heterogeneous

Cyclostomes have

circular cells, quite small, 12.6. in diameter. In Teleosts and

Ganoids (carp and Amza), two of the more specialised groups,

the size is about equal, 15 u.xg. and I11p.x6p. The

size increases in Elasmobranchs, represented by the ray and

shark, it is 22.6—28.5, (short diametér not given). The

52 EDITH J: “CLAYPORE:

most generalised fish, the Dipnoan or lung-fish, possesses still

larger corpuscles, 41 w.x 29. Here in this series speciali-

sation is accompanied by decrease in size. (Plate II., Figs.

10-14) Again, among the Amphibians, the Cecilians, limb-

less, tailless, scaly, worm-like animals, the corpuscles are

small, 18.3 w.x 15 4, nearly circular. Frogs and toads, very

specialised in many respects, have corpuscles 22 yp. x 16 /,

approximately. Zyvzton gives cells 25x16 o0r 32.5 x —both

sizes are given, but there is no basis to judge which figures

are correct. Megalobatrachus, the great Japanese salamander,

has corpuscles 47 uw. x 33 4 =Cryptobranchus, the American

cousin of this foreigner, agrees in size of these cells, 48.7 w.

x 29.2 4. These are two air-breathing, tailed Amphibians,

far more generalised in gross structure than the frogs and

toads. The three following ones, MVecturus, Proteus, the

blind cave form of Europe, and Szren, all very generalised

forms, make a group together, their corpuscles measure 58.4

pe X31, 584 X35 ph, 594. x.30p. Last in this list is

amphiuma, an air-breathing form, but possessing the largest

corpuscles known, 75 4.x 45 pw. Thus again among the

Amphibians there is a regular decrease in size accompanying

an increase in specialisation. (Plate II., Figs. 15-20) But

few forms of reptiles can be discussed, and there is less varia-

tion in those examined. Turtle shows corpuscles 15 yw. x

6y.; snake, 15 p. x 12.9 w.; lizard, 15 py. x 10 pp alliogeges

20x 7 (Plate IT., Figs: 21, 22). All are much smallenitian

those of the Amphibians, agreeing more with the Teleosts and

ganoids. In the birds there is a still further decrease in

size, the fowl and pigeon agreeing incorpuscles, 12 uw. x7 yp.

Finally, among mammals the circular corpuscles vary from

2.5 py. togy., averaging 6.5. The only other circular cells

known are the nucleated corpuscles of the lamprey and hag

fishes, which are larger, as shown in the table; they average

12.6 yp. in diameter.

In this whole series there is a gradual decrease in size

from the generalised to the specialised forms, not only in the

different members of the classes, but also in the different

COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE. 53

classes themselves. At each end of the table are specialised

forms—not equally so, but both far from primitive—modern

fishes and birds and mammals. Between them are less

specialised forms, and among these are found some of the

largest corpuscles known. None of them are of greater inter-

est than the amphibia, a class acknowledged to contain most

widely varying forms, some highly specialised and others

exceedingly generalised. The worm-like, degenerate Cecili-

ans have small, nearly circular corpuscles (Plate Il., Fig. 15),

and from this there is a steadily increasing series, culminating

in the fairly gigantic cells of Amphiuma. Passing away from

amphibians, on the other side, the size again decreases, and,

finally, in the mammals are some of the smallest cells known.

There is one point more of interest to notice in these cells.

It is, perhaps, only an accidental coincidence, but the cells

of all the presumably degenerate forms examined are approxi-

mately circular, if not completely so. The lamprey 12.6 yp.

in diameter; Cectlian, 18 w. x 15 y.; snake, 16 uw. X13 ys

There is another striking change in this series besides

decrease in size. The normal absence of the nucleus from

mammalian red corpuscles and the presence of it in all other

red corpuscles is weil known. Can the loss of this part be

explained, a part so essential to ordinary cells? Considera-

tion of the function of the red cell will assist in answering

this question. It is no longer a typical cell; its protoplasm

is highly specialised for one purpose, to hold hemaglobin

(this substance makes 90 per cent. of the corpuscle), which

in turn serves to take up, during the circulation of the blood

through the lungs or skin, the oxygen essential for maintain-

ing life. In all reserve cells the nucleus is the organ of

division ; through its means two cells arise from one. In

other cells it may assume some other function. The red

blood corpuscle with its protoplasm saturated with hemaglo-

bin has become highly specialised for one function, to carry

oxygen; the more hemaglobin carried, the more efficient is

the cell in its work. The original use of the nucleus is lost,

the work of the cytoplasm prevents it from acquiring a

54 EDITH J. CLAYPOLE:

secondary use, it becomes a rudimentary cell organ, decreases

in size and, when specialisation is pushed to the extreme, dis-

appears altogether. Inthe most highly developed animals,

the mammals, in which activity and power are greatest and

most constant, and the necessity for rapid supply of oxygen

to the tissues most urgent, the red corpuscles are reduced to

a mass of protoplasm saturated with hemaglobin, a voracious

oxygen eater. The nucleus is gone, it only occupied pre-

cious space, which is far better filled with the oxygen carrier.

What else could be expected than this loss when the oxygen

carrier is at sucha premium? For loss it is, despite those

who maintain the presence of a nucleus in mammalian red

blood corpuscles. The advantage of the increased possibility

far outweighs any use this rudimentary organ may have had,

hence its loss. This disappearance is gradual, large in amphi-

bians, the nucleus is reduced to a mere line in birds (Plate L.,

Fig. 3) to vanish entirely in mammals normally.

The gradual decrease in size of the cells is very readily

explained on the same principle. Chemical exchange takes

place far more rapidly and completely in many small masses

than in a few large ones. A consequent decrease in size

attended by a great increase in number takes place, resulting

in a very large number, 5,000,000 per cu. mm. of 7 uw. bodies

(man), against 56,000 of 58 y. bodies (Vecturus). The hema-

globin is increased in amount by loss of nucleus and rendered

far more accessible by decrease in size of these cells. These

advantages gained show reason enough for this law of

decrease in size and the gradual loss of the nucleus in the

adult corpuscle of mammals. Perhaps a series of careful

observations on the blood of mammals and birds might show

connecting links between the non-nucleated and nucleated.

corpuscles.

Here is a general law of decrease in size attending speciali-

sation established for one tissue. Is this a general law appli-

cable to all tissues? Blood is a tissue of a very special

nature, and another possessing at least many similar qualifi-

cations is strzped muscle.

COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE. 55

MUSCLE:

The ultimate structure of striped, or, as it is often called,

voluntary muscle, is in many points even yet under discus-

sion, many complicated theories being suggested as possible

explanations of the appearances found under the microscope.

These, however, are not the points to be discussed, but

rather some others usually only incidentally noted, yet from

a comparative standpoint of significance.

It is well known that the nuclei of the striped muscle fiber

of mammals lie just under the sarcolemma or limiting mem-

brane of the muscle fiber. In the frog the nuclei, as shown

in transection, are scattered through the contractile substance

of the fiber. The constancy of these respective positions

shows them not to be merely accidental, but characteristic of

each animal. Other points also appear of greater or less

importance: size and shape of fiber; number, shape and size

of nuclei; arrangement of fibers in fascicles and the structure

of the sarcous substance as apparent from longitudinal and

transections.

The following animals have been used; in all cases possible

animals of the same physiological value were chosen ; they

were treated subsequently by the same processes in all pos-

sible cases: lamprey, Amza, Protopterus, frog, Amblystoma,

Cryptobranchus, Necturus, turtle, snake, pigeon and cat.

The results are arranged in the following tabulated form :

CLAYPOLE

EDITH J.

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COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE. 57

These facts do not run quite as smoothly as in the first

case.

The line between the muscle fibers having nuclei imbedded

in the sarcous substance and those having them at the edge,

is drawn between the cold and warm-blooded animals—fishes,

amphibians and reptiles—against birds and mammals, with

one exception, the Dipnoan (Protopterus), in which the nuclei

are at the edge as in birds and mammals; they are much

larger, however, than in the latter fibers. The number of

nuclei visible from a transection is, on the whole, the same,

averaging 2-3, again with one exception, to be discussed

later.

The terms coarse and fine have been used to describe the

appearance of these fibers in transection. The explanation

of this appearance is probably that the fibrils forming the

fibers vary in size in different animals. A transection of a

fiber involves transections of its constituent fibrils. If these

are small the fiber looks fine-grained (Plate III., Figs. 29, 32 ;

Plate V., Fig. 43); if large, ia\ coarse) effect results (Plate

Pie rig. (30; Plate .1V., Pigs. 30,438039)5.4ln Jonge

sections there is alsoa noticeable difference. In longitudinal

view of ordinary striped mammalian muscle the cross-stripes

are usually far more prominent than any others. In some of

the more generalised forms the cross-stripes become merged

into very much emphasised longitudinal striations (Plate III.,

Fiz-33; Plate 1V., Figs. 35, 37).. -Ubis difference, canbe

explained by the varying size of the fibrils; if they are large

their size gives the effect of longitudinal striations. In the

largest these become more strongly marked than the charac-

teristic cross-stripes.

One animal presents some very peculiar conditions. In

the snake there are two kinds of fibers shown in transec-

tion; one is typical, coarse-grained, with 3-4 oval nuclei

imbedded in the sarcous substance ; the other is very dense,

close, showing long cracks and lines across the surface, divid-

ing it into irregulargareas. The second marked difference

between this fiber and the typical one is in the number

58 EDITH. J.’ CLAVPOLE:

of nuclei. Instead of 3-5 in each section there are as

many as 25-35, an enormous increase. It appears from

this view as if there were two distinct kinds of fibers.

Examination of a longisection at once shows this to be

untrue. These two apparently distinct structures belong

to the same fiber; they pass abruptly into each other. The

typical muscle is faintly cross-striped and rather clearly longi-

tudinally striated. It has long oval nuclei scattered here

and there through it. Suddenly this structure stops, the

fiber becomes slightly larger in diameter, it loses all cross-

stripes and nearly all longitudinal markings. The sarcous

substance is dense and compact. Instead of a few oval

nuclei there are a large number of small round ones scattered

through it (Plate V., Fig. 41). So far as I know this is only

found in snake muscle. Isolated material should be exam-

ined in order to fully investigate this peculiar condition ; at

present all that I can suggest is that it is some peculiar end-

ing of the fibers. In the pigeon there is a slight difference

also shown in cross-section between the muscle fibers ; some

appear coarse and others very dense, but in longisection

there is no appreciable distinction to be made.

So here again is the same law, large fibrils in the general-

ised forms, small ones in the specialised. This is fairly con-

sistent, the snake and dipnoan being the only exceptions.

The presence or absence of the so-called Cohnheim areas

is also significant. These are divisions of the fibers (visible

in transection) by irregular lines passing over the surface,

probably caused by the massing of the fibrils into bundles.

In specialised forms (lamprey, frog, bird, cat, Figs. 26, 27,

32, 42, 43) these areas are present, in generalised forms they

are absent (Figs. 30, 34, 36, 38). The Dipnoan is a note-

worthy exception to this rule, as the position of the nuclei

also shows.

The question of size must necessarily be approached with

caution. In form, muscle fibers are not so independent of

physiological changes as are red blood, corpuscles. A fully

developed active muscle fiber is well known to be larger than

COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE. 59

an ill-developed one. Hence differences are to be expected

between animals with good and those with but slightly devel-

oped muscular systems. This point must be borne in mind ;

also another, that all animals are not equally active at all

times of the year, and that there may be a difference in size

of fibers under the different physiological conditions to which

they are subjected.

There isa great range in size among fibers examined,

from I0 ys. to 97 yw. The smallest are those of lamprey, a

relatively inactive animal, but it also has its other tissue

elements small. The Amza and Dipnoan follow in this series

in size.

The frog, strongly muscular when active, has fibers 45 yu.

in diameter. Ambdlystoma, Cryptobranchus, Necturus, follow

in gradually increasing sizes. Turtle is smaller, snake, an

exception, larger, but bird and mammal are both small.

This series, in spite of variations, coincides fairly well

with the series of blood corpuscles in all but one or two

respects, which can be explained in part by the interference

of other agents. In spite of increase in muscular power

there is a gradual decrease in size from the generalised to

specialised. No one would compare favorably the slow,

sluggish Cryptobranchus or Necturus with birds or mammals

in regard to muscular power, yet the former have far the

largest fibers, which ought to indicate muscular activity, if

size is the sole criterion. Very small size in Cyclostomes

may be caused by specialisation and by lack of muscular

activity. The one striking exception in size, the snake

fibers, may perhaps be accounted for by its exceptional mode

of locomotion. The difficulty of movinga limbless body over

the ground is very great, and this demand for great force is

satisfied by great increase in size of fibers. The peculiar

second kind, possibly special endings, cannot at present be

discussed. The other possible explanation in size lies in

degeneration, or reversion rather, back to a primitive condi-

tion.

The change of position and decrease in size of the nuclei

60 EDITH J.) CLAVBOLE®

is perhaps easier to explain. In its physiological action the

force is exerted in a lengthwise direction through each fiber,

ultimately by contraction of fibers. The presence of nuclei,

non-contractile masses, must prevent, to aconsiderable degree,

the fibrils about them from producing the full effect of their

contraction, since they must pull obliquely around the nuclei.

Decrease in size of nuclei assists somewhat in preventing this

waste by straightening the pull somewhat, but by pushing the

interfering bodies to the wall, or, in other words, to the

sarcolemma, completely obviates the difficulty ; the fibrils

can exert their full power and yet the nuclei remain to per-

form their function, whatever it may be. This is effected in

the two highest classes—birds and mammals ; in them muscu-~

lar activity is at a premium in force and endurance. The

decrease in size of the fibrils is also in favor of action ; the ©

same number of fibrils can be crowded into a smaller space

and so more fibrils be present and a far more efficient nerve

supply and blood supply. Owing to the small fibers the

exchange between blood and tissue must be more rapid with

small than large fibers.

While considering for a moment the results of these

observations it may be objected to that blood is not a good

tissue for basing an argument of this kind on. It is so

intangible, always changing its chemical nature, always

moving from place to place. But the very singleness of its

aim renders it one of the best. Its function is the same for

all animals, its movements practically the same; through this

series the development of an essential mechanism can be

tra¢ed, until it finally attains perfection in the highest forms

of animal life, the mammals. Muscle is also a very special-

ised tissue, and is instructive in showing the mode of

development along an essentially different line.

Briefly summing up we find the results, on the whole,

harmonious ; a general law can be deduced which applies to

the main animal tissues. The more generalised the animal

the larger the tissue elements; the more highly specialised

the smaller.are the elements. This is a very natural law ;

COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE. 61

all growth and change in body depends on growth and change

in cells forming it. It is but logical to expect such profound

changes to show their influence on these important agents.

Exceptions to it are found, of course, ‘‘no rule without an

exception” says the old adage. Such should, however, be

expected since the evolution of these elementary tissues is

conditioned by the same laws as that of the animal as a

whole. It is a commonly accepted fact that a form may be

highly specialised in some lines and yet possess one or more

very generalised structures. So an animal may, as a whole,

be generalised in its tissues as Dipnoan (Protoperus), yet

exhibit some one specialised tissue, for instance, its muscle

marking it at once from the other tissues.

This same line of treatment can be equally well applied

to any other tissues, simple or compound, but at present I

have not sufficiently examined or studied them to discuss the

results, though an interesting field of work is opened by this

method of treating the elementary structures of animal

bodies by the same methods as have long been used in com-

parative anatomy.

62 COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE.

PLATE I.

Red blood corpuscles (drawn from fresh material). Except figure 7.

Fig. 1. Amia—Ganoid.

Fig. 2. Snake.

Fig. 3. Pigeon.

Fig. 4. Frog.

Fig. 5. Cryptobranchus.

Fig 6. Necturus.

Fig. 7. Amphiuma.

Fig. 8. Lamprey (petromyzon).

Fig. 9. Human.

64 COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE.

PLATE II.

Diagrams of blood corpuscles.

Fig. 10. Lamprey (cyclostome).

Fig. 11. Carp (teleost).

Fig. 12. Amia (ganoid).

Fig. 13. Sturgeon (elasmobranch).

Fig. 14. Protopterus (dipnoan).

Fig. 15. Cecilian (amphibian).

Fig 16. Frog (amphibian).

Fig. 17. Salamander (amphibian).

Fig. 18. Cryptobranchus (amphibian).

Fig. 19. Necturus (amphibian).

Fig. 20. Amphiuma (amphibian).

Fig. 21. Turtle (reptile).

Fig. 22. Snake (reptile).

Fig. 23. Pigeon (bird).

Fig. 24. Camel (mammal).

Fig 25. Man (mammal).

Some of these are reconstructed from measurements.

Pe es ae

Ss — = ae (o)

aa S ee

66 COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE.

PLATE Ill.

MuscLe.—Transections and longisections of striped muscle fibers.

Fig. 26. Lamprey. Body muscle.

Fig. 27. Amia. Esophagus.

Fig. 28. Protopterus. Longisection of body muscle.

Fig. 29. Protopterus. Transection.

Fig. 30. Amblystoma. Transection.

Fig. 31. Frog. Longisection (Sartorius).

Fig. 32. Frog. Transections.

Fig. 33. Amblystoma. Longisection.

Longitudinal striations shown in Amblystoma and are absent in Protopterus

and frog.

PLATE III.

sj.

1 \ i i i 4

hee mem.

—_—

a aus Sa ye agt th a 7 * _ sie ae =A

eats 4 7 ay has a ae

eT. at aa, re") iy 2 : ie 7. oat a 7

i A 45 : : <. . r . ix a > 7

na. ‘ SOR? A, ae

a > « a . : , : ae 7 oe # :

‘ Fo va : awa _ at ed ee r, ie

= . » <> a oe — i

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( -

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68 COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE.

Fig.

34-

35:

36.

37:

38.

39:

PLATE IV.

MuscLe—( Continued).

Cryptobranchus. Transection of muscle in skin.

Cryptobranchus. Longisection.

Necturus. Transection of skin muscle.

Necturus. Longisection of skin muscle.

Turtle. Transection, from long retractor of head of animal.

Snake. Transection. Coarse fiber.

7O COMPARATIVE HISTOLOGY OF BLOOD AND MUSCLE.

PEATE. V.

MuscLe—( Continued).

Fig. 40. Snake. Transection of fine fiber, many nucleated (only partially

filled in).

Fig. 41, Snake. Longisection showing the meeting of the two kinds of

fibers and different forms of the two kinds of nuclei.

Fig. 42. Pigeon. Transection (from sartorius) showing two kinds of fiber

in transection.

Fig. 43. Cat. Occipito-scapularis. Transection.

THE PHYSICIAN AND HIS MICROSCOPE.

By A. A. YOUNG, M. D., Newark, N. Y.

One of the most expensive and one of the most useless

pieces of office furniture that the ordinary physician possesses

is his microscope. It usually occupies a most commanding

and conspicuous place in the office and decorated with ‘‘fuss

and feathers”; valueless as an educator, valuable for the

macroscopical appearances of the microscope, for it is capable

_of producing wonder and awe to the office visitor and shekels

to the pocket of the physician.

Nothing can be said against the microscope as an instru-

ment, for its value resides in its intelligent use, and unless

used intelligently it becomes worse than useless, distorting

facts and fancies alike, from which the observer can form no

concept, can draw no conclusion save an erroneous one.

The physician has to deal with the organic world, with those

material forms in which resides that peculiar, unresolvable

and unknowable agent we call life, and without which matter

becomes comparatively valueless.

The microscope in the department of medicine requires

for its intelligent manipulation a familiarity with anatomy,

pathology, bacteriology, and last, but not least, biology,

which subject scarcely ever enters into a medical college

curriculum. We, as physicians, must deal with material

forms that are endowed with life, and of that relation which

exists between the material form and life we must have some

concept, though it be partial and inadequate, for on the rela-

tion of things material or immaterial is the development of

human thought possible. The life force of the bacillus is

doubtless as intricate as the life force of the human subject

and may be similar if not identical with it; for what is the

72 Ay A YOUNG:

body in which the ego resides more than an aggregation of

amebe specialised, and each ameba possibly having an inde-

pendent life and having reproductive properties of its own.

It is with the minute mass of matter, not the molecule, that

the microscopist has to deal; he sees its manner and method —

of growth and not the forces which produce the molecular

arrangement of the ultimate particles.

It is not enough that the physician be able to observe and

differentiate the various forms of the micrococcus, spirillum

or bacillus: he must know as well the habitat, manner and

method of growth of each variety. Without this knowledge

the revelations of the microscope are no more intelligible than

some Egyptianinscriptions. There isa philosophy of micros-

copy which is equally as valuable as the facts on which it is

based, but a philosophy that can only be developed by

accurate observation and classification of microscopical data.

This work, it is evident, must be performed by the skilled

microscopist and not by the novice, in which class the busy

practitioner is usually found. In microscopical analysis no

element relative to accuracy can with safety be omitted. It

matters not though the microscopical accessories be thor-

oughly cleansed and sterilised, for the results would be equally

untrustworthy if the material to be examined be placed in a

receptacle, found perhaps in some old garret and half cleansed.

Conclusions reached under such conditions must be errone-

ous. Do you ask who ever allows such procedures? Go to

the home of the amateur or pseudo-microscopist, observe his

methods and technique and you will have the answer. It is

surprising how much we see, how much we assume and how

little we know. A young physician asks an older one for the

use of his microscope to examine a specimen of urine, assur-

ing its owner that he is familiar with the instrument, having

had instruction in college ; permission granted, and slide pre-

pared, and the observer exclaims, ‘‘ The most beautiful speci-

men of a cast I have ever seen ;” the owner of the instrument

says, ‘‘ That looks like vegetable matter and not a cast.”

‘‘No,” said: the other, ‘‘that is a urinary cast; I. have seen

THE PHYSICIAN AND HIS MICROSCOPE. 73

many of them.” A microscopical examination of the con-

tainer and its contents revealed a corncob for a cork; what

the cast was you may readily infer.

A physician of several years’ standing and the possessor

of a good microscope at an autopsy of his announced that the

patient’s death was due to a disease of the kidneys, that she

had been passing blood, pus, all forms of casts and other bad

material with the urine. The autopsy, however, revealed

ulceration with pus formation, degeneration and rupture of

the gall-bladder, produced by impacted gall-stones, while the

kidneys were practically normal, showing no _ structural

degeneration. From whence, then, came the blood, pus,

casts and débris, which was alleged to have been seen?

These cases could have been none other than of mistaken

identity ; something was inferred that did not exist.

The conclusion is therefore reached, justly or otherwise,

that the eye and understanding must be educated independ-

ently along certain lines before the manipulation of the micro-

scope becomes satisfactory and trustworthy ; objects must be

seen and known relatively and in their entirety before being

resolved into their component elements ; the macroscopical

appearance of an object must precede its microscopical

appearance.

The physician must know in what menstruum and under

what conditions the objects for which he is searching exists

or are developed. Neither is it enough for him to know and

recognise the various forms of bacilli; he must be able to

classify them and know their manner and method of growth,

what they produce by their growth and what influence they

have upon humanity. This is the philosophy of microscopy

as relates to medical science. The microscope therefore

becomes to the physician valuable in the degree that he is

able to classify and arrange its revelations so that they

may be read as from an open book. This faculty means

a familiarity with the instrument born of time,—time

which the ‘‘country doctor” must give by piecemeal, if

at all.

74 A. A. YOUNG:

I am no pessimist, although I see in a degree the

passing of the microscope so far as it relates to the indi-

vidual work of the ordinary medical practitioner. As

already intimated, this passing is induced and sustained by

unskilled and untrained eyes, which see much and indi-

vidualise little.

The structure of microscopy, if it be enduring, must be

built upon a comparatively errorless macroscopy. The rank

and file still have to learn that the microscope only enables

the investigator to continue his eyesight so as to observe the

primary structure of an organised mass that would otherwise

remain unknown and unknowable.

The first essential, then, for a physician microscopist is

the proper use of his eyes, supplemented by a keen intellect ;

what he sees he must be able to describe accurately, thus

differentiating the various forms and figures that appear in

the visual field.

Neither is it enough for him to recognise an object in an

isolated condition and know its form and construction: he

must know as well what relation it sustains to other objects

about it. This calls for the exercise of the comparative

faculty, the second essential for the physician microscopist ;

indeed, these two elements may be called his eyes. With

these faculties undeveloped, untrained, he may as well be a

blind microscopist. What is true of normal vision is pre-

eminently true of aided vision, which aid the microscope is,

but it produces changes also in the relative conditions of

objects, and of such changes the mind must take cognisance ;

it is an element too often overlooked. In short, the revela-

tions of the microscope becomes the alphabet and the sys-

tematic arrangement of these revelations in the human mind

forms its language, a language that requires study to com-

prehend ; a language also that needs much further develop-

ment and amplification. Physicians, as a rule, can be

novices only in microscopical science, following where

others lead; they stand at your feet, at the feet of the

miscroscopists of the world, in the relation of pupil to teacher,

THE PHYSICIAN AND HIS MICROSCOPE. 75

asking for more light to illuminate the intricacies of human

existence.

Give to them this light; save for them the microscope

with all of its powers and possibilities which are vast ; prevent

it by your efforts from relapsing into a state of ‘‘innocuous

desuetude.”

THE PERITONEAL EPITHELIUM OF SOME ITHACA

AMPHIBIA.'

(Necturus, Amblystoma, Desmognathus and Diemyctylus.)

ISABELLA M. GREEN, A.B. (BucHTEL), M.S. (CoRNELL), AKRON, OHIO.

This investigation was undertaken with a view to deter-

mining the character of the epithelium of the peritoneum of

the tailed Amphibia of the Cayuga lake basin. The Amphz-

bza selected for this work represent the orders Protezda and

Urodela. Of the former, only one species, Mecturus macu-

/atus, is included, while three families of the Uvrodela are

represented, viz., dmblystomide, by Amblystoma punctatum;

Desmognathide, by Desmognathus fusca ; and Pleurodelide

by Diemyctylus viridescens. One of the Anoura, Rana vires-

cens, was used by way of comparison.

It was the intention to makea study of the various species

at all ages and at different seasons. This, however, has

been impossible, except ina few cases. No Wecturz could

be examined after spawning and Amdlystoma punctatum was

the only species taken in the fall. Immature specimens of

Necturus and Desmognathus and larve of Desmognathus were

studied. By combining all the species we have a series com-

posed of (1) larve ; (2) immature; (3) mature before spawn-

ing; (4) mature soon after spawning; (5) mature taken in

August ; and (6) mature taken in the fall.

As regards the use of the term epithelium, authors differ.

Ranvier, Klein, Kolossow and Piersol apply it only to the

covering of the mucous membranes, using endothelium for

the covering of the serous membranes. Paladino, Neumann,

1. This paper was presented to Cornell University for the degree of M. S., in June, 1896.

PERITONEAL EPITHELIUM OF AMPHIBIA. Teh

Toureux, Hermann and Waldeyer discard the term endothe-

lium, and call the covering of the serous as well as the

mucous membranes epithelium. The term epithelium is used

throughout this paper.

This investigation was carried on in the anatomical labora-

tory of Cornell University. I wish to express my apprecia-

tion of the facilities and material so generously placed at my

disposal, and my gratitude to Dr. Wilder, Professor Gage and

Instructor Hopkins, for their interest, encouragement and

kindly criticism.

HISTORICAL.

For many years the serous membranes have been the sub-

ject of numerous investigations. Most of the work has been

done upon mammals, but a number of articles have been

written concerning the peritoneum of the Amphibia. The

frog is the amphibian generally used, although Toureux

(74) worked upon the 7yrzton, and Kolossow (’93) upon

one salamander, two species of 7rzton and the A-volotl, in

addition to the frog and toad.

Unfortunately their meagerness of data and details made

it impossible to get the greatest good from the work of others.

Often the statements were so vague that it was difficult to

decide just what the author meant.

Among the first to work on the amphibian peritoneum

was Mayer (‘32 and ’36). His results were not of great

assistance, for although he spoke of finding cilia upon the

peritoneum of the frog, the sex and age of the animal were

not mentioned.

Valentine ('42?), in an article upon Ciliary Motion,

enumerated the parts in a series of animals upon which cilia

are found. Among them was mentioned the peritoneum of

the tailed Amphibians, the Triton being given as an example.

Cilia were found upon the serosa of the ovary.

Leydig (57), in his Manual of Histology of Man and

Animals, says that in the frog there are cilia upon some parts

of the peritoneum, but not upon the mesentery, but does not

78 ISABELLA M. GREEN:

state the sex of the animal examined. He also found cilia

upon the mesoarium.

The next work was of a more specific character, being a

paper upon The Presence of Ciliated Epithelium upon the

Peritoneum of the Female Frog, by Thiry (62). He found

cilia upon the peritoneum lining, the ventral wall of the body

cavity, and upon the membranes around the mouth of the

oviduct, but none upon the serosa of the liver, and does not

“mention their occurrence upon any other part of the peri-

toneum. Thiry proved by experiment that the current pro-

duced by the cilia was in the direction of the mouth of the

oviduct.

V. Recklinghausen (62) was the first to use silver nitrate

upon the epithelium of the serous membranes as a means of

bringing out the cell boundaries.

Ordmansson (’63) spoke of finding stomates in the peri-

toneum of the frog and rabbit.

In 1863, v. Recklinghausen demonstrated by a number of

experiments the presence of stomates in the peritoneum of

the rabbit.

In the Ardezten aus der Physiologischen Anstalt su Leipzig

for 1866 appeared four papers treating either of the epi-

thelium of the serous membranes or of their relation to the

lymphatic system. They were as follows:

1. Upon the Absorption and Excretion of the Pleural

Wall, by Dybkowsky.

2. Upon the Centrum Tendineum of the Diaphragm, by

C. Ludwig and F. Schweigger-Seidel.

3. The Treatment of the Animal Tissues with Silver

Nitrate. Upon Epithelium as well as upon the Lymph

Canaliculi of v. Recklinghausen as the Supposed Origins of

the Lymphatic System, by F. Schweigger-Seidel

4. Upon the Peritoneal Cavity of the Frog and its Con-

nection with the Lymphatic System, by F. Schweigger-Seidel

and J. Dogiel.

In the first three of these papers is discussed the question

of the communication of the lymphatic vessels with the peri-

PERITONEAL EPITHELIUM OF AMPHIBIA. 79

toneal and pleural cavities in mammals. Dybkowsky found

small openings leading from the pleural cavity into the

lymphatics. The others also found stomates.

The last paper mentioned above was especially helpful,

both on account of the definite and careful statements made

and the conclusions arrived at. The authors showed that (1)

ciliated cells are present on the peritoneum of the adult

female frog only; (2) the ciliated cells occur either singly or

in groups among the non-ciliated cells ; (3) ciliated cells are

smaller and have more regular boundaries than the non-

ciliated cells ; (4) ciliated cells stain more deeply with silver

nitrate than the non-ciliated cells; (5) the direction of the

current is toward the mouth of the oviduct, and they there-

fore conclude that the cilia are for the purpose of aiding the

ova to reach the opening of the oviduct ; (6) the presence of

stomates was demonstrated in the septum cisterne lymphatice

magne.

Afonassiew (’60) denied the presence of stomates.

Klein (72) has written much concerning the serous

membranes. In 1872, ina paper on Remak’s Ciliated Vesicles

and Corneus Filaments in the Female Frog, he described at

length the ciliated vesicles found in the mesentery and meso-

gastrium of the female frog. He believed they are sinuses

belonging to the lymphatic vessels and that, perhaps, they

become ciliated only under pathological conditions. He

mentions cilia as occurring between the stomates as well as

on their borders.

In Klein’s comprehensive work upon the lymphatic system

he treated in Part I. (73) of the serous membranes, and in

Part II. (75) of the lung. Klein demonstrated the presence

of stomates leading from the pleural and peritoneal cavities

into the lymphatics, and gave a full description of both the

connective tissue and the epithelium of the serous mem-

branes. He described the ciliated, germinating epithe-

lium of the mesogastrium of the female frog as being

present during the winter months, but he neglected to state

whether this was the case in the male also and whether in

80 ISABELLA M. GREEN:

‘the female the cells were germinating and ciliated during the

summer.

Toureux (’74) made some investigations upon the 77zton

as well as the frog. He believed that the places which

others took for stomates were merely depressions in the

membrane.

The next year, 1875, two papers pertaining to the peri-

toneum of the frog appeared. The first one by Grunau

(75), treated of the ciliated epithelium upon the peritoneum

and of the oviducts of the adult female frog. He found

cilia upon the peritoneum lining the ventral and dorsal walls

of the body cavity and upon the liver and membranes about

the mouth of the oviduct and that the frequency of ciliated

cells diminished as the distance from the mouth of the ovi-

duct increased. Grunau stated that ciliated cells are smaller,

but project more than the non-ciliated.

The second paper was by Neumann and Grunau (’75).

They found cilia upon the peritoneum of the adult female

frog and the 7rzton, the sex of the latter not being men-

tioned.

Toureux and Hermann (’76) considered the places which

had been described by others as stomates as merely the cen-

ters of cell formation.

Nicolsky (’80) stated emphatically that ‘‘the cilia upon

the epithelium of the serous membranes of the frog exist in

all individuals without distinction of sex and age.” He

qualifies this statement, however, by saying that the cilia

do not extend over so much space in the male and young

female as in the adult female, and that ‘‘in the males the cilia

are very short—one must search a long time for them.”

Purser (84) also went so far as to say that ciliated epi-

thelium is found upon the peritoneum of the male frog, as

well as the female, although not in such large quantities, and

all this after having made the statement that the motion of

the cilia is supposed to aid the ova in their passage to the

mouth of the oviduct.

Some of the standard authors, such as Huxley, Quain

PERITONEAL EPITHELIUM OF AMPHIBIA. 8I

and Piersol, mention the occurrence of stomates upon the

peritoneum in both Mammalia and Amphibia and a number

treat of ciliated epithelium upon the peritoneum of the frog,

but in many cases no definite data as to age and sex are

given.

Ecker (’89), in his extended work upon the Anatomy of

the Frog, spoke of cilia being present upon the peritoneum,

but did not state definitely whether this was the case in both

sexes and all ages.

Kolossow ('93) worked upon two species of Rana, one of

toad, two species of 7yzton, one of salamander and the

Axolot/ and found cilia only in the adult female of the 77z¢on,

frog and A ro/otl.

PERITONEUM.

The peritoneum is the serous membrane lining the abdomi-

nal cavity. It is a closed sac, excepting in the female, where

the opening of the oviducts break the continuity. In Amphz-

bza the parietal peritoneum tightly adheres to the body wall,

and the visceral completely invests all the viscera, with the

exception of the kidneys, which are covered only on one

side. The diagrams (Figs. I—3) show the peritoneum as it

appears in sections cut through the peritoneal cavity of

Necturus at different levels.

The peritoneum is developed from the mesoderm. Accord-

ing to Minot (92) the specialised layer of the mesoderm,

called mesothelium, lines the body cavity and covers parts of

the viscera. At first the cells of the mesothelium are cuboi-

dal and cylindrical, but as development goes on they become

reduced in thickness and finally reach the thin plate-like

form of the epithelium. From the mesothelium is also

derived a layer of mesenchyma, which finally becomes the

connective tissue stratum of the peritoneum.

The peritoneum is a thin shining membrane, through

which the different organs can be plainly seen. It is com-

posed of (1) the connective tissue stratum and (2) a single

layer of epithelial cells.

82 ISABELLA:>M. GREEN:

The first consists principally of bundles of white connective

tissue. In Mecturus these form a thick network. The fibers

are arranged in wavy rows, either parallel or crossing each

other. (Fig. 4.) Numerous fine elastic fibers are present.

They often branch, as is shown in Fig. 4. In the mesen-

tery of the small intestine were found bundles of smooth

muscle cells. Although not very numerous some were of

quite good size. (Fig. 5.) A single cell is shown in Fig. 6.

The nuclei are thicker and more rounded than the typical

rod-shaped nucleiof smooth muscle cells. In the peritoneum

lining the dorsal wall of the body cavity of Mecturus are

numerous pigment cells which branch and anastomose. (Fig.

7.) Pigment cells occur in different parts of the peritoneum

in the various Amphzbza studied. In Dzemyctylus, the peri-

toneum covering the dorsal wall of the body cavity and the

testes, is very densely pigmented. In all of the Uvrodela

examined there was some pigment in the peritoneum, princi-

pally in the serosa of the testis, the dorsal wall of the body

cavity and the mesentery of the intestine.

The epithelium of the peritoneum is a simple squamous

epithelium. The cells are united by a thin layer of cell

cement. For determining the character, shape and size of

the epithelial cells and their relation to each other, three

principal methods of investigation were employed: (1) The

examination of fresh material in blood serum or normal salt

solution. (2) The application of silver to the fresh material.

(3 The preparation of sections. The first method is especi-

ally recommended by Klein in his work on serous mem-

branes. It proved very advantageous in detecting the pres-

ence of cilia, as they are visible with a high power both in

motion and at rest. The method of procedure is as follows:

A bit of the peritoneum is spread out on a slide in a drop of

blood serum or normal salt solution and covered with a cover-

glass, care being taken not to rub or tear the epithelium.

With a 2 mm. oil immersion objective the cilia can be seen,

both on the edge of the preparation in profile and also on the

surface in face view. Normal salt solution proved as good a

PERITONEAL EPITHELIUM OF AMPHIBIA. 83

medium‘as blood serum. At first the cilia move so rapidly

that they can scarcely be seen, but the speed gradually slack-

ens until they only move a few times a second and ‘finally

stop altogether. In the fresh preparations the nuclei are

visible but the cells are not demarcated.

OCCURRENCE OF CILIA.

The ripe ova are shed into the abdominal cavity and must

pass cephalad to reach the mouth of the oviduct. The ques-

tion of the presence of cilia upon the peritoneum of Vecturus

is a very interesting and important one, as up to the present

time no one has published any statements concerning the

passage of the ova from the ovary tothe oviducts orthe find-

ing of ova in the oviducts. According to Marshall (’93), in

the frog the ova are propelled partly by the muscular action

of the body walls and partly by the motion of the cilia

on the peritoneum. So far as I know, the first means

has not been demonstrated, and it is hard to see how

the muscular action of the body walls would tend to force

the ova into the oviduct. If the sole purpose of the

cilia is to propel the ova towards the mouth of the ovi-

duct, then we should expect to find cilia in the adult

female and at the period of ovulation only. It is possible

that cilia may be developed in the female at maturity and

then remain during the rest of the animal's existence, but

their presence would not be looked for in the male and young

female. Hence, it seems strange that Nicolsky and Purser

described cilia upon the peritoneum of the male as well as

the female, even if only in small quantities.

In both sexes of Vecturus the peritoneum was thoroughly

examined fur cilia in the following parts: the hepatic liga-

ment, the ventral wall of the body cavity, the dorsal wall of

the body cavity, the membranes near the mouth of the

oviduct, the mesopneumon, the mesogastrium, the serosa of

the stomach, the serosa of the liver, the serosa of the small

intestine, the mesentery of the small intestine, the mesentery

84 ISABELLA M. GREEN:

of the large intestine, the spheno-hepatic ligament, the gastro-

hepatic ligament, the gastro-splenic ligament, the serosa of

the ovary, the mesoarium, the serosa of the testis, the mesor-

chium, the peritoneal fold supporting the oviduct, and the

peritoneal fold supporting the vas deferens.

In Necturus maculatus cilia were found only in the adult

female. The male Vecturi were destitute of cilia upon the °

peritoneum (Fig. 8) and females, in which the ova were only

one-third the size of those which would be laid in the spring,

showed the same condition as the males. These immature

females measured 28 and 29 cm., but in one female only 28

cm. in length, cilia were as long and as widely distributed

over the peritoneum as in the large specimens. Although

this animal was smaller than the others the ova were nearly

mature. Adult female Mecturz, 32.5 cm. in length, were

examined before ovulation. In them cilia occurred in great

abundance upon certain parts of the peritoneum. Cilia were

constant in all the adult female Vecturz examined from Janu-

ary to April on the following parts, viz., the hepatic liga-

ment (Fig. 9), the ventral wall of the body cavity (Fig. Io),

the membrane near the mouth of the oviduct (Fig. 11) and

the serosa of the liver (Fig. 12).

On these parts of the peritoneum cilia were very gener-

ally distributed. Examinations were made at intervals over

the surface and ciliated cells were found on every piece

examined. Not every cell was ciliated, however. On the

ventral wall ciliated cells were distributed from the pelvis to

the cephalic end of the abdominal cavity. About one-half

the number of adult female Vecturz showed ciliated cells on

the dorsal wall of the body cavity also. Where they occurred,

they were distributed on the cephalic third of the dorsal wall

and fewer cells were ciliated. No cilia were found in Vectu-

yus upon the mesentery, serosa of the ovary nor mesogastrium,

although various writers have described cilia in these parts

in the frog. Waldeyer (70) spoke of cilia being present

upon the mesentery of the frog, presumably in the female,

as he mentioned cilia also upon the mesoarium. Thiry

PERITONEAL EPITHELIUM OF AMPHIBIA. 85

(66) found cilia upon the serosa of the frog’s ovary, and

Klein ('73) upon the mesogastrium, and Leydig upon the

mesoarium. Ecker ('89) found cilia near the openings of

the oviducts, and Grunau (’75) upon the serosa of the liver

of the female frog and also near the oviducts, and Neumann

(75 upon the serosa of the liver of the female frog and in

Triton cristatus.

In specimens of adult Amdlystoma punctatum, taken just

before ovulation, cilia were found upon the hepatic ligament

(Fig. 13), the ventral wall of the body cavity, the membrane

near the mouth of the oviduct, the serosa of the liver, the

mesoarium and the fold of peritoneum supporting the ovi-

duct, but none upon the dorsal wall of the body cavity.

Adult female Amdélystomas, taken soon after ovulation, as

well as those taken in August, showed cilia in the same

places as those taken before ovulation. Cilia were present

in Amblystoma punctatum on the hepatic ligament and the

serosa of the liver (Fig. 14) during the fall. This was deter-

mined by sections cut of a preserved specimen taken in

October and killed in December. Very probably cilia

occurred in other places, but it was impossible to see them

in the sections. In male Azmdlystoma no cilia were found.

No immature females were examined. From this it is

evident that in Asmblystoma punctatum cilia persist through-

out the year.

In adult female Dizemyctylus viridescens before ovulation

cilia occur upon the hepatic ligament (Fig. 15), the ventral

wall of the body cavity, the membranes near the mouth of

the oviduct and the serosa of the liver. No cilia were noticed

upon the dorsal wall. Neither immature females nor any

females after ovulation were examined. Male Diemyctylus

showed no cilia upon the peritoneum.

In adult female Desmognathus cilia were present before

ovulation upon the hepatic ligament, the ventral wall of the

body cavity and the membranes near the mouth of the ovi-

duct, but not upon the dorsal wall of the body cavity. A

young female with immature ova possessed no cilia upon the

86 ISABELLA M. GREEN:

peritoneum. Two larval Desmognathi showed no trace of

cilia, although serial sections were made of the whole body.

The male Desmognathus had no cilia upon the peritoneum.

From the foregoing observations we see that, in all four

species examined, cilia were always present in the adult

female and that no cilia were found in the male or immature

female, so far as examined.

Arrangement of Ciliated Cells.—Ciliated cells occur either

singly or in groups between the non-ciliated cells. This was

well shown in the fresh preparation. (Figs. 11 and 16.) The

condition mentioned by Grunau of the ciliated cells being

arranged in stripes radiating from the mouth of the oviduct,

has not been noticed, although I found that the ciliated

cells were most numerous near the mouth of the oviduct.

(Fig. 11.)

Direction of Current.—To determine the direction of the

current produced by the cilia, powdered carmine was placed

upon the peritoneum immediately after the death of the

animal. By the aid of a simple microscope it was seen to

move towards the mouth of the oviduct and was finally drawn

into the opening. Mrs. Gage’s method of using minute

blood clots instead of carmine was tried, and proved more

successfulthan the carmine. Immediately after death a small

blood clot was placed upon the peritoneum covering the

ventral wall of the body cavity of an adult female MVecturus.

It traveled 10.5 mm. in ten minutes in the direction of the

opening of the oviduct. Three hours after death a clot trav-

eled only 6 mm. in ten minutes. In an adult female Vectz-

rus, where cilia were present on the dorsal wall, the direction

of the current of the cilia on the dorsal wall also was in the

direction of the mouth of the oviduct. Thiry demonstrated

the direction of the current in the frog as being towards the

mouth of the oviduct by using black pigment.

As the ciliary currents in Vecturus are present only in the

adult female and the direction of the current is toward the

mouth of the oviduct, it seems to strengthen the theory that

the cilia are to aid the ova in reaching the oviduct.

PERITONEAL EPITHELIUM OF AMPHIBIA. 87

The questions now arise when do the cilia make their

appearance, are they persistent throughout the year and how

are they developed? At present these are matters of specu-

lation. To find out just when the cilia appear and how long

they remain it would be necessary to examine a great number

of specimens of all ages. As to their development there are

various theories. Kolossow offers it as a suggestion that the

irritation of the peritoneum, through the increase of the

ovary in size about spawning time, may cause the appearance

of cilia upon the peritoneum. Klein says that the ‘‘ germinal

cells in the female are ciliated,” and Nicolsky calls the

ciliated cells young epithelial cells. Schweigger-Seidel and

Dogiel consider them as arising from the ciliated cells of the

oviduct, while Grunau is not sure whether this is the correct

view or whether the cilia are developed from the common flat

epithelium of the peritoneum. Neumann holds this latter opin-

ion, and Kolossow speaks of certain cells which are thicker than

the others and covered with minute points which finally develop

into cilia. This question I have not been able to decide.

The ciliated cells are usually smaller but thicker than the

others, but I could find no appearance of cilia just beginning

to develop. There is little difference in the length of the

cilia upon various parts of the peritoneum, although near the

mouth of the oviduct they are generally longer.

STOMATES.

The subject of stomates has been much discussed ever

since v. Recklinghausen first described them in 1862. Since

that time many investigators have noticed them, both in

mammals and the lower vertebrates. According to the best

authorities stomates are small openings leading from the

peritoneal or pleural cavities into the lymphatic vessels.

They are described by v. Recklinghausen as being in the

rabbit twice the size of a red blood corpuscle. Others

merely say that they never exceed the size of an epithelial

cell. They are usually surrounded by a radiating form of the

88 ISABELLA M. GREEN:

epithelial cells. There may occur around the stomate a

number of small granular cells, which Klein (’73) called

‘‘ germinating cells.” In the female frog he found that these

cells possessed cilia. By Schweigger-Seidel and Dogiel

(66) the stomates are described as funnel-shaped, the

smaller end being on the lymphatic side of the membrane.

The supposed function of the stomates is to furnish a passage

for the lymph from the peritoneal and pleural cavities to the

lymphatic vessels.

A great diversity of opinion exists regarding the stomates.

Many writers do not believe in their existence, but ‘the pre-

vailing opinion seems to be in favor of them. V. Reck-

linghausen ('63) and Dybkowsky (66) demonstrated by

experiments the presence of stomates in mammals, and

Schweigger-Seidel and Dogiel (’66) in the frog. Ordmans-

son (63) figures large and small stomates. Klein (73)

describes and figures stomates in the septum cisterne lym-

phatice magne.

No doubt there is great danger of mistaking openings or

precipitates for true stomates. Piersol said that sometimes

the end of one of the processes of a connective tissue cell

may protrude between the epithelial cells and, taking a

brown stain with silver nitrate, be easily mistaken for a

stomate. Such appearances he, with other writers, calls

pseudo-stomates or stigmata. Toureux and Hermann (76)

said the so-called stomates are merely depressions in the

membrane, which become filled with an albuminous liquid

and so form a precipitate with silver nitrate. If such is the

case, by thoroughly rinsing with distilled water these appear-

ances may be avoided.

Stomates are especially abundant in the septum cisterne

lymphatice magne of the frog. This I have found to be

the case in the female of Rana Virescens (Figs. 17-18). The

cells are arranged in a radiating manner about the opening,

the nucleus in nearly every case being situated in the end of

the cell bordering on the stomate. No small cells are

present around the opening. In Necturus maculatus there is

PERITONEAL EPITHELIUM OF AMPHIBIA. 89

no cisterna lymphatica magna and I could find no stomates

anywhere in the peritoneum, although various methods of

injection were tried and microscopical examinations of both

the fresh and hardened material were made. Certain appear-

ances (Fig. 19) I could not account for, but they are probably

artificial.

PORM ANDESIZE On CEUs:

To bring out the boundaries of the cells v. Reckling-

hausen’s silver method was adopted. Perfectly fresh material

was used, as it was found that tissue which had been used

for the examination in normal salt solution did not silver

well, the salt and blood serum forming a precipitate with the

silver nitrate, even though care was taken to rinse it well with

distilled water before silvering. In membranes which had

silvered in bright sunlight the lines of cell cement were sharp

and dark, but when the process went on slowly in a dim

light the effect was not so good as a brown precipitate was

formed over much of the surface of the cells.

Ciliated cells stain more deeply than the non-ciliated

(Fig. 8). Whether this is due to the presence of cilia or to

albumen being retained between the cilia is at present

unknown.

The cells of the epithelium vary greatly in form from the

almost regular hexagonal shape of the cells of the serosa of

the liver (Fig. 20) and testis (Fig. 21) of Mecturus to the

very serpentine form of the mesentery of Diemyctylus (Fig.

22). The number of sides varies from four to seven, the

most common number being five or six. The difference in

form is in a great measure due to the stretching or non-

stretching of the tissue.

Schwartz, in an article in the Anatomischer Anzeiger for

1893, proved that this was so in the case of the peritoneal

epithelium of the cat andthe rabbit. He showed that when

the organs were distended the epithelial cells of the peri-

toneum surrounding them were larger and of more regular

outline than when the organs were empty. This was tried

gO ISABELLA M. GREEN:

on the mesentery of NMecturus and Dzemyctylus by stretching

and hardening the membrane and then comparing the form

of the cells with those from part of the same membrane

which had not been stretched. In the first case (Fig. 23)

the cells were larger and quite regular in outline, while in

the mesentery, which had not been stretched (Fig. 24), the

cells were very sinuous in form and so contracted that they

appeared smaller than the others.

There was no appreciable difference in the form or size of

the epithelial cells between the male and female. In every

case noticed in NVecturus the cells on the dorsal wall of the

body cavity (Fig. 25) were larger than those on the ventral

wall (Fig. 10). Ciliated cells are usually smaller than the

non-ciliated cells, but thicker, so that they project more than

the others (Figs. 9 and 10). In Wecturus the cells of the

serosa of the liver and other solid organs are more regularly

hexagonal than on any other part. Probably this is due to

the fact that these organs are more uniform in shape and

size than the others. The shape of the cells of the hepatic

ligament, serosa of the liver, mesopneumon and membrane

between the spleen and lungs and between the liver and

lungs are shown in Figs. 26, 27, 28, 29 and 30.

Measurements.—In length the cells averaged 57.3 ys, in

breadth, 39.8 », while the average thickness was 12.31 p.

The average size of the nuclei near the mouth of the oviduct

in Necturus was, length, 38 7 uw, width, 22.5 w#., and thick-

néss, 8:75 ~: The average length of : the cilia-upon me

hepatic ligament in the female Vecturus was 3 12 yp. and of

those upon the membranes near the mouth of the oviduct

was 3.75 -.

NUCLEI:

The nuclei are usually large, oval or kidney-shaped.

They are nearly always placed eccentrically and generally

the nuclei of two adjacent cells are juxtaposited. The cells

project opposite the nuclei. In the epithelium of the peri-

PERITONEAL EPITHELIUM OF AMPHIBIA. gt!

toneum, covering the contracted stomach and intestine of

Necturus, a peculiar condition was noticed. The rows of

cells seemed to be arranged in pairs. In each pair the

nuclei were juxtaposited so that there was the appearance of

the nuclei being situated in double rows (Fig. 31). But

when the organ was distended this appearance was lost

(Fig. 32). Occasionally a cell with two nuclei was noticed

(Fig. 33).

SUMMARY.

The result of this investigation may be summed up as

follows :

1. The peritoneum is made up of two parts, viz., the con-

nective tissue stroma and the ggpithelium.

2. The connective tissue stroma is composed of white

connective tissue, elastic fibers and bundles of smooth muscle

cells.

3. The peritoneal epithelium was ciliated only in the

adult females studied. It was impossible to demonstrate

cilia in the males or young females, although their presence

upon the peritoneum of some Amphzbza has been described

by a few writers.

4. All the specimens of MNecturus, Desmognathus and

Diemyctylus were taken from January to April and none were

examined after spawning. Specimens of Amdlystoma were

examined both before and shortly after spawning and in

August, and one specimen which was taken in October and

prepared in December.

5. Inthe adult females of all the species named taken in

the spring and in August, cilia were constant upon the

following parts: Hepatic ligament, the ventral wall of the

body cavity, the membranes near the mouth of the oviduct

and the serosa of the liver.

6. In Necturus some of the adult females showed cilia

also upon the dorsal wall of the body cavity.

92 ISABELLA M: GREEN:

7. Specimens of adult female Asdblystomas taken in the

spring and in August differ from the other species in having

cilia upon the mesoarium and the membrane supporting the

oviduct.

8. In a single example of adult female Asmzblystoma

taken in October and prepared in December, cilia were

present upon the hepatic ligament and the serosa of the

liver.

9. The direction of the current produced by the cilia is

toward the mouth of the oviduct.

10. As indicated by the current the function of the cilia

is probably to carry the ova to the oviducts.

11. Blood clots were carried by the cilia on the ventral

wall immediately after death at the rate of 10.5 mm. in ten

minutes, and three hours after death at the rate of 6 mm. in

ten minutes.

12. No stomates were found in Wecturus maculatus.

13. The shape of the cells varies greatly, but most of this

variability is due to the stretching or non-stretching of the

tissue.

14. The size of the cells varies in different parts of the

peritoneum and in different species.

15. The cells on the dorsal wall of the body cavity are

usually larger than those on the ventral wall.

METHODS.

The specimens were killed in 1-6 chromic acid, ether being

added to the proportion of 5 c.c. to the liter. The abdomen

was then opened and the various parts of the peritoneum were

examined for the presence of cilia. The tissues were kept

moist with blood serum or normal salt solution.

Bits of clotted blood or finely powdered carmine were used

to determine the direction of the ciliary currents.

Other specimens which had not been utilised in the above

PERITONEAL EPITHELIUM OF AMPHIBIA. 93

manner were treated with silver nitrate. After the abdomen

was opened and the specimen thoroughly washed in distilled

water to remove the blood and lymph, a I-5 per cent. solu-

tion of silver nitrate was poured over it and the viscera care-

fully moved so as to allowthe silver to reach every part of the

peritoneum. This was permitted to remain two or three

minutes, or until the peritoneum had a silvery cast. Then

after several washings with distilled water the specimen was

placed in a porcelain dish with plenty of distilled water in

the direct sunlight or the strongest daylight until the peri-

toneum was of alight brown color. In the bright sunlight

only a few minutes were required.

For a nuclear stain Gage’s hematoxylin (Gage, 1892,) was

the most successful. In preparations showing the face view

of the epithelium no stain beside hematoxylin was used. In

the sections eosin was used as acounter stain. For the study

of the connective tissue, the membrane was gently penciled

to remove the epithelium. A 2 per cent. acetic acid caused

the white connective tissue to swell up and become trans-

parent, so the elastic fibers which were unaffected by the acid

stood out plainly. Van Gieson’s picric acid fuchsin (Free-

born, 1893,) was used to stain the white connective

tissue.

The tissue was hardened simply in alcohol, 50, 67 and

82 per cent. being used, the time for the first two being one

to three days and the tissues were left in 82 per cent. until

needed. Picric alcohol 1 to 3 days and then 67 and 82 per

cent. alcohol was also used, but the picric acid tended to

obscure the cilia.

Hardened tissues were mounted in balsam and glycerine

jelly was used for the fresh.

Both the paraffin and collodion methods were used ‘in

imbedding and sectioning.

The larval forms were hardened, some in Fish’s picro-aceto-

sublimate, and others in formalin and imbedded whole in

collodion and sectioned.

For the dissociation of the epithelial cells various reagents

94 ISABELLA M. GREEN:

were tried, but equal parts of Gage’s picric alcohol and water,

2 to 4 hours, proved the most successful.

To determine whether the change in the form of the cells

was due to the stretching of the membrane the following

method was employed. Pieces of the fresh mesentery and

hepatic ligament of Mecturus were stretched over Hoggan’s

histological rings, treated with silver in the usual way and

hardened. The mesentery of Diemyctylus being too small to

cover a ring, the necks of small homeopathic vials were used

for this instead of rings. The small intestine of Mecturus

was stretched by distending it and then hardening.

BIBLIOGRAPHY.

This list includes only such books and papers as were

helpful in this investigation. Extended bibliographies are

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Hauten. Virchow’'s Arch., Bd. XLIV. (1868), pp. 37-68, Taf. III. and

IV.

?75. Arnold, Julius— Ueber das Verhalten der Wandungen der Blutgefiasse

bei der Emigration weisser Blutkérper. Virchow’s Arch., Bd LXII.

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776. Arnold, Julius—Ueber die Kittsubstanz der Endothelien. Virchow's

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°78. Arnold, Julius—Ueber die Durchtrittsstellen der Wanderzellen durch

entziindeteserése Haute. Virchow’s Arch, Bd. LXXIV., pp. 245-267,

Tai. Vir:

785. Baker, Frank—Peritoneum. Reference Handbook of the Medical

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°67. Cohnheim, J —Ueber Entziindung und Eiterung. Virchow’'s Arch.,

Bd. XL. (1867), pp. 1-79.

’89. Cope, E. D.—The Batrachia of North America. Bull. No. 34, U. S.

National Museum. Washington, D. C. (1889).

766. Dybkowsky—Ueber Aufsaugung und Absonderung der Pleurawand.

Arb. aus der Phys. Anstalt zu Leipzig. Bd. I. (1866), pp 40-67. I

plate.

789. Ecker, Alex.—The Anatomy of the Frog. Translated with additions by

George Haslam. London (1889).

?75. Foa, P.—Ueber die Beziehung der Blut und Lymphgefisse zum Saft-

kanalsystem. Virchow's Arch., Bd. LXV. (1875), pp. 284-300.

’O1. Gage, S. H.—Life History of the Vermilion spotted Newt (Dzemyctylus

viridescens. Raf). Amer. Nat., Dec, 1891, pp. 1084-1110.

702. Gage, S. H.—An Aqueous Solution of Hematoxylin which does not

Readily Deteriorate. Proc. Amer. Soc. of Micr., Vol XIV (1892), pp.

121-127.

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704,

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78.

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Pas

¥7/8 3

PERITONEAL EPITHELIUM OF AMPHIBIA. 95

Gage, S. H.—Improvements in Oil-sectioning with Collodion. Proc.

Amer. Micr. Soc, Vol. XVII. (1895), pp. 361-370.

Gould, Geo. M.—An Illustrated Dictionary of Medicine, Biology and

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Grunau, Hermann—Ueber das Flimmerepithel auf dem Bauchfell des

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Hoffman, C. K.—Bronn’s Klassen und Ordnungen des Thierreiches.

Vol. VI. (1878),' Part II., Amphibia.

Huxley, T. H —Article: Amphibia, in the Encyclopedia Brittanica.

Vol. I. (1875).

Klein, E. B.—On Remak's Ciliated Vesicles and Corneous Filaments of

the Peritoneum of the Frog. Quar. Jour. Mic. Soc., Vol. XII. (1872),

Pp. 43-50

Klein, E.— Handbook for the Physiological Laboratory. Edited by J

Burdon-Sanderson Vol I., Text. Vol. II., Plates (1873).

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Plate XXII.

Lee, A. B.—The Microtomist’s Vade Mecum. Third Edition (1893.)

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(1857.1

Ludwig, C., and F. Schweigger-Seidel— Ueber das Centrum Tendineum

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Marshall, A. Milnes—Vertebrate Embryology, p.99. NewYork. (1893.)

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(1883), pp. 1-77-

Wiedersheim, A.—Salamandrina perspicillata und Geotriton fuscus.

Genua (1875).

Wiedersheim, R—Elements of the Comparative Anatomy of Verte-

brates. Adopted from the German by W. Newton Parker. London

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Freeborn, G. C.—Van Gieson’s Picro-Acid Fuchsin as a selective stain

for Connective Tissue. N. Y. Path. Soc., 1893, p. 93, Vol. IV. Studies

from the Dept. of Pathology of the College of Physicians and Surgeons,

Columbia College, N. Y., Vol. IV , for the Collegiate year 1894-1895.

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98 PERITONEAL EPITHELIUM OF AMPHIBIA.

PLATE I.

Fig. 1. Transection through the cephalic part of the abdominal cavity of

Necturus maculatus, showing the peritoneum and its relation to the body

wall, liver, stomach, lungs and oviduct.

a. = white connective tissue fibers. Ov. = ovary.

6. = elastic fibers. pf. = peritoneum.

c. = pigment cells. st, = stomach.

o. = oviduct. Vv. = postcava.

S. = spleen. x. == dorsal aorta.

z. == small intestine. y- = portal vein.

e. = lung. i. = liver:

Fig. 2. Transection through the body cavity of Mecturus farther cephalad

than Fig. I.

Fig. 3. Transection through the body cavity of Mecturus at middle of

small intestine.

Fig. 4. Fresh mesentery of small intestine of Mecturus maculatus.

Epithelium removed by penciling.

Fig. 5. Bundle of smooth muscle cells from mesentery of small intestine

of Necturus maculatus.

Fig. 6. Isolated smooth muscle cells from mesentery of small intestine of

Necturus maculatus. j

Fig. 7. Peritoneum from dorsal wall of body cavity of Mecturus macu-

fatus. Fresh, epithelium removed by penciling.

a. = ciliated cell.

b. non-ciliated cell.

c. = cell folded over, showing cilia in profile.

PLATE. IT:

1Ziomm

1/ 1oomm.

1/100 mm.)

I0O PERITONEAL EPITHELIUM OF AMPHIBIA.

PLATE II.

Fig. 8. Cross section of the serosa of the liver of male Necturus, show-

ing absence of cilia.

Fig. 9. Cross-section of the epithelium from the hepatic ligament of adult

female Vecturus, showing cilia.

Fig. 10. Surface view of peritoneal epithelium from the ventral wall of

the body cavity of adult female WVecturus.

Fig. 11. Surface view of fresh peritoneal epithelium near mouth of ovi-

duct of female Vecturus.

Fig. 12. Cross-section of epithelium from liver of female Vecturus

Fig. 13. Cross-section of hepatic ligament of adult female Amblystoma,

taken just before spawning.

Fig. 14. Cross-section of serosa of liver of adult female Amblvstoma,

taken in October.

Fig. 15. Surface view of epithelium from hepatic ligament of female

Diemyctylus.

Fig. 16. Surface view of fresh peritoneal epithelium from hepatic liga-

ment of female WVecturus.

PLATE II.

etary, eaves ya,

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eh MLLER! ie Oe erst 1 eee

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102 PERITONEAL EPITHELIUM OF AMPHIBIA.

PLATE Ill.

Fig. 17. Peritoneal side of septum cisterne lymphatice magne of Rana

virescens.

a. = stomate.

Fig. 18. Lymphatic side of septum cisterne lymphatice magne of Rana

ULV eSCENS.

a. — lymphatic opening of stomate, shown in Fig. 17.

Fig. 19. Peritoneum from dorsal wall of body cavity of male Mecturus.

a. — appearance not accounted for.

6. = opening between epithelial cells, probably artificial,

Fig. 20. Face view of epithelium from ventral surface of liver of male

Necturus.

Fig. 21. Face view of epithelium from testis of male Vecturus.

Fig. 22. Face view of epithelium from mesentery of small intestine of

female Dzemyctylus.

PLATE IV.

1/ loomm.

——————— ee

1/7 icomm.

elie Als

ire”

104 PERITONEAL EPITHELIUM OF AMPHIBIA.

PLATE IV.

Fig. 23. Face view of epithelium from the stretched mesentery of small

intestine of male Dzemyctylus.

Fig. 24. Face view of epithelium from the unstretched mesentery of small

intestine of male Dzemyctylus.

Fig. 25. Face view of epithelium from the dorsal wall of the body cavity

of male Mecturus.

Fig. 26. Face view of epithelium from the hepatic ligament of female

Necturus.

Fig. 27. Face view of the epithelium from the mesopneumon of male

Necturus.

PLATE IV.

1/7 1icomm,

i a eS

ee Scie nan

pe wes

Ss ey tana i wal ponte

shah, sieaeg ti, Se x

Jenison

bay eee

106 PERITONEAL EPITHELIUM OF AMPHIBIA.

PLATE V.

Fig. 28. Face view of epithelium from the membrane between spleen and

lungs of male Necturus.

Fig. 29. Face view of epithelium from the liver of male Desmognathus.

Fig. 30. Face view of epithelium from the mesopneumon of female

Diemyctvlus.

Fig. 31. Face view of peritoneal epithelium from the contracted small

intestine of male Mecturus.

a. — peculiar arrangement of the nuclei.

Fig. 32. Face view of the peritoneal epithelium from the distended small

intestine of the male Mecturus.

Fig. 33. Epithelial cell from the hepatic ligament of the female Vecturus

with two nuclei.

Fig. 34. Isolated epithelial cells from the hepatic ligament of male

Necturus.

PHOTOMICROGRAPH Y.

THOMAS J. BRAY, Warren, O.

The subject of the paper assigned me, as you will see by

the program, is Photomicrography by the Use of Ordinary

Objectives, Practically Considered. The primary object

of the paper is to show what can be done with such objec-

tives as are to be found in the outfit of a physician or ama-

teur, and to aid, as far as possible to simplify and popularise

this beautiful process. The theme being a practical con-

sideration of the art, it precludes the idea of a scientific dis-

cussion of the subject, hence I shall, in very plain words, give

you a brief description of the methods which I have found

best suited for this work. I will also narrate some of my

failures, trusting they will act as a warning to those who may

be working along this line, in order that they may avoid

similar errors. With these introductory remarks, I ask your

kind attention to the subject matter of the paper.

A photomicrograph has been defined briefly and properly

as a ‘‘ Macroscopic photograph of a microscopic object,” in

contradistinction to a microphotograph, which means ‘‘a

microscopic photograph of a macroscopic object.” I will

make these terms a little plainer by saying that a photo-

micrograph is.a photographic enlargement of a minute object,

and a microphotograph is a photographic reduction of a large

object. By impressing upon your minds the fact that a

photomicrograph is an enlargement and a microphotograph

a reduction of. the objects by photography, then these terms

will not be as liable to be misused as they sometimes are.

For many years I labored under the impression that in order

to be successful in the production of photomicrographs, I

108 THOMAS |: sb Awves

would have to use objectives that were constructed for that

special purpose, that the chemical, optical and visual foci

should be coincident. I found, in reading up on this subject,

that most writers so express themselves ; some of them go

so far as to give directions how to get a general average of

these foci. They advise to work by trial and error, thus: to

expose a plate slightly nearer the object than the visual

focus, then another slightly farther away, and in this way find

the proper location for the sensitive plate.

Recent works on photomicrography, notably Professor

Gage’s book on Microscopic Methods, states that good photo-

graphs can be made by the use of the ordinary objectives.

He gives some very practical advice on this subject. I made

many trials as per instructions given in the text-books, but

the results were a hazy, out of focus, unsatisfactory negative.

I sought the advice of some of my friends whom I supposed to

be masters of the art, but I got the invariable answer, ‘‘that

to be successful I must use objectives specially corrected for

that purpose.” I failed to see why I should not be able to

get just as good an image on the plate as I could get on the

focusing screen, provided the plate and screen were exactly

in the same plane. I so expressed myself and was as often

told, ‘‘that when I knew more about the subject, I would

understand the reason why corrected objectives were a neces-

sity.” These expressions from experts only made me more

eager to succeed according to my views and judgment as an

amateur photographer of many years practice. I persevered,

however, making many scores of failures, when at last I

made this discovery, that I was beginning at the wrong end—

using high power objectives before I had learned to work

with the lower powers. I reasoned thus: that high power

objectives, such as 1-8, I-10 or I-15, gave a small field and

poor light, and that they required the nicest and finest

adjustments, the greatest skill, the very best optical appliances

and apparatus to operate them, and the most effective light

for their illumination that could be obtained. The low

powers, on the other hand, gave a larger field, the result

PHOTOMICROGRAPH Y. 109

being a small picture. It then dawned upon me that what

was required for successful work was to enlarge these small

pictures by the use of a long camera, that is, to work upon

the principle of the photographer's enlarging process rather

than by the use of high power objectives. These views I

have proved by many practical demonstrations, to my own

satisfaction at least, to be correct.

I shall now take up the subject of apparatus, lighting,

focusing and finishing of the negative, giving the details of

the work as I practice them. The apparatus consists of a

long bellows camera. This may be made of several sections

of light-tight pine boxes, blackened inside to eliminate all

reflections from the sides, and made to slide in each other,

having a focusing screen and a plate holder attachment on

the end of the rear section, and an arrangement at the front

end section for securing the tube of the microscope to it.

This may be a slip tube, or a black bag, or any simple con-

nection that is perfectly light-tight and capable of contrac-

tion and expansion to suit the movement of the microscope

tube in focusing the object, or preferably a camera made

specially for this work may be used. If large negatives are

to be made, I would strongly advise doing away with the

camera altogether and use a dark room to serve the purposes

of the camera, the microscope and light being on the outside

and the tube of the microscope fitted to a door or shutter,

thus shutting out all light from entering the room save that

which comes through the objective. On the inside of the

dark room construct a rack for carrying a movable piece suit-

able for holding the focusing screen and plate holder. This

would be a very cheap and complete arrangement. The

operator would, of course, stand inside the camera or dark

room. A microscope is not a necessity ; any arrangement

that will hold the slide centrally and permit of the light pass-

ing through the object will answer the purpose. I use a

microscope simply because I have one and on account of its

convenience in making necessary adjustments and focusing.

The operation of picture-making is as follows: The

IIO THOMAS J. BRAY:

tube of the microscope is turned down so that it lies ina

horizontal position; it is then attached to a short bellows

and it, in turn, to the front of the camera. The substage

bar and mirror bar is swung around out of the way. A

Welsbach incandescent gas burner is placed back of the

stage about ten inches distant, with the bright white flame

located centrally. About midway between the gas jet and

the stage is placed a bull’s-eye condenser with the flat side

towards the object, and by placing a piece of white paper on

the stage the light is centered upon it ; that is, I focus the

bull’s-eye by moving it to or from the light so as to get the

best even clear light possible. When this is done the paper is

removed and the slide to be photographed is placed in its

position on the stage. Some prefer a mechanical stage, but

as they are expensive I could not afford this luxury, but

have managed to get along without one by using Bausch &

Lomb’s glass stage ; its movements are easy and after a little

practice I find it answers all my purposes. The objective is

now put in place and run down to about the working distance.

The object can now be seen on some part of the ground glass

screen, perhaps indistinctly; when observed it should be

focused by the unaided vision and the object centered care-

fully on the ground glass. If the circle of light is out of the

center, then the camera and the microscope are not in line.

Adjust them by moving the tube end of the microscope to

the right or left, up or down, as required and shown by the

circle of light on the ground glass. If the circle of light is

not as large as the object, then an objective of lower power

must be used. With a six-inch to three-inch variable I have

a considerable range of field and amplification, and with a

six-foot bellows extension to my camera, I have under my

control a great variation in-amplification, besides being able

to photograph many large objects up to five-eighths of an inch

in diameter. Objects that are larger than this, I take with an

ordinary photographic camera. The focusing arrangement

used is an extension to the pinion shaft; it is attached to

the milled head and extends beyond the camera a couple of

PHOTOMICROGRAPH Y. Hea

inches ; on the end of this extension a loose lever, having a

tightening screw in its hub, is placed, the lever extending

down to within half an inch of the table. To the lower end

of this lever a piece of stiff wire is fastened, the wire being

as long as the camera bed, and is held in place by passing

through eyes screwed into the bed-piece of the camera.

This focusing device was invented by Dr. Mercer, and as I

have not heard of his patenting this device, it can be used,

presumably, by all who wish to doso. By the use of this

attachment, the utmost nicety of adjustment can be made.

After focusing carefully by the unaided vision, the thumb

screw is tightened in the hub of the lever, then, by moving

the wire rod to or from the object, a very fine focus can be

obtained. With this arrangement I can focus a one-eighth

water immersion objective by exercising a little care, as the

slightest movement of the wire reduces the movement of the

tube about one-twentieth of the motion given to the rod.

Consequently there is no occasion to use a fine adjustment at

all. The focusing screen is the ordinary ground glass

screen, with Mr. Walmsley’s improvement thereon. This

consists of cementing with balsam, cover glasses, at several

points around the limits of the picture and one in the center,

all on the ground side of the screen, thus showing clear glass

at these points. This is a very good focusing device, in

fact, the best I have tried.

It is used thus: First focus by the eye, as nearly correct

as possible, on the ground glass part, then with a two-inch

eye-piece, used as a focusing glass, focus sharply on the

cover glasses. If an object is of uneven surface, then focus

for the part that is required to be shown clearly, or take a

general average of the whole object. Take, for example,

the fly’s tongue. This object has an uneven surface ;

hence, if the focusing is done upon the hairs on the

false trachea, then the spirals will not be so sharp; if we

focus on the spirals, then the hairs will be slightly out of

focus; therefore, in such cases, a general average focus must

be taken to show the object as a whole. The objectives I

I12 THOMAS J. BRAY:

use for photomicrography are Bausch & Lomb’s student ©

series, from one-eighth down to six inches. These will

answer every purpose of the non-professional or amateur.

One of the most useful objectives that I know of is one made

by them. It is a six-inch to three-inch variable ; it has a

very good definition, and, by turning a milled collar, any

range of amplification can be obtained within range of the

objective, and with this lens and a long camera a great vari-

ety of work can be done. It is particularly useful for histo-

logical specimens, as it will light the whole of an object,

provided it is not over five-eighths of an inch in diameter,

For subjects larger than this, I resort to the ordinary photo-

graphic method of copying and enlarging, as before stated.

For example of that kind of work, | point you to the photo-

graph of the firefly, which is exhibited for that purpose. To

summarise, first adjust the light, then put on the lowest

power objective that will give the amplification desired, and

that will also give a circle of light extending beyond the

outer edges of the object. Extend the camera until the pic-

ture is of the size wanted, focus again, then attach and use

the lever focusing-device before mentioned. Focus sharp

on the cover glass spots, using a two-inch eye-piece, or a

focusing glass for this purpose. When this is done, put in

the color screen between the bull’s-eye condenser and the

stage of the microscope and expose about three or four times

as long as you would with the same light and conditions

without the screen. The screen used is one made by

Bausch & Lomb for cloud photography, and it belongs to my

8 x 10 view outfit. Ihave it rigged up on a stand for the

purpose herein named. It is a most useful affair for all

objects that have a yellow tinge in the balsam or the object.

It is indispensable with me for many objects; for example,

the photographs of arranged diatoms on some of the souvenir

cards, also on the large photographs in the frame, where some

are very transparent, others not so transparent, and some

are quite dense. The use of the screen seems to have the

same eftect on such objects as it has upon the clouds in a

PHOTOMICROGRAPH Y. Irk3

landscape view. It in a great measure evens up, as it were,

the different lights in the object, that is to say, it retards the

high lights, which are apt to be over-exposed, to a greater

degree than it does the middle lights and the shadows.

Many of the diatoms in the picture shown would not be seen

at all, were it not for the effect of this bi-chromate cell. I

will here relate an experience I had previous to using this

screen: My friend and co-worker, Mr. Harry’G. Carter, of

Minneapolis, sent me a slide of the proboscis of a large blue-

fly, the one pictured on some of the souvenir cards, and

the one shown in the large picture exhibited. I tried to

photograph this slide and made over a dozen failures. I

wrote to Mr. Carter that I could photograph a slide that I

owned and make a success every time, but that I utterly

failed to make a single picture from his slide ; that the best

results I could obtain was an ‘‘out of focus, hazy” kind ofa

negative. He replied that my lenses were not suited for the

work, and that I could not expect to succeed with the

objectives I was using. I answered him that with another

slide I had, of the same object, I could get a good picture

every time I made an exposure, hence I could not agree with

him. Soon after this I tried the color screen and made a

success of it at the first trial. This convinced me I was

right, that the fault was outside of the objective. To still

further test this matter, I bought a one-inch ‘‘no name”

objective in a ‘‘spectacle shop” in Cleveland. It cost me

$4.00 with a brass box. I bought it because it was a cheap

affair and certainly could not have been specially corrected

for photography. I tried this objective and made some

splendid good sharp pictures with it. I have it with me,

also a specimen of the work it has done. Should anyone

present be curious to examine them, they can do so at the

close of this session.

The sensitive plate will now be considered briefly. I find

in my practice that almost any of the standard make of plates

will give good results. I have used Seed’s, Cramer’s, East-

man’s, Stanley’s, Carbutt’s, Hammer’s and many others, and

I14 THOMAS) J BRAY: =

got along very nicely with all of them; yet I have a decided

preference for Cramer’s slow isochromatic plates. They are

a little slow, but they are much easier to work with than the

more rapid ones. With the Welsbach incandescent light

and a low power objective, using Cramer's crown plates with-

out a color screen, the exposure must be made in about a half

second or the plate will be spoiled from over-exposure. Of

course, much depends on the character of the object. 1

would strongly advise slow plates, especially for those not

well up in the operations of photography.

After the exposure comes the developing. This is done

in the same way, and by the same reducing agents, as is

practised by the ordinary photographer. There are a num-

ber of good mixed developers made, and in the photographic

journals may be found the formula for compounding them.

They all have merit. I can specially recommend Mr.

Walmsley’s ‘‘ Universal Developer” as being very suitable

for this purpose. I use a compound known as ‘‘ Monarch

Developer ;” it is prepared and sold by W. S. Bell & Co., of

435 Wood street, Pittsburg. It is a universal developer, suit-

able, when diluted, for negatives, transparencies, lantern

slides, bromide paper, and the like. It is a very clean, clear

compound, and can be used over again repeatedly. Itis com-

posed of two reducing agents—namely, hydrochinon and para-

amido-phenol. Ihave used it for several years and can fully

recommend its use as a developer. The fixing bath that I

consider best is an acid bath, with chrome alum as a hardener.

This I make according to Cramer's or Carbutt’s formula. It

clears, fixes and hardens, and is used over again until too

weak to be effective ; it is then thrown away and new bath

made. After the plate has been fixed and cleared it is

thoroughly washed, preferably in running water, for one hour

to eliminate the last trace of the hypo left in the film by the

fixing process.

The negative is now to be carefully examined. If it is

found to be dense enough to print from, it is then laid ona

rack to dry. If it appears thin, then intensifying must be

PHOTOMICROGRAPH Y. IIT5

resorted to to bring up the density or opacity of the high

lights, after which it is washed well and laid aside to dry.

When dry and hard, wipe the film side with a rag dipped in

alcohol ; this hardens the film and cleans it off smooth and

clear. Some think that a negative when dry and hard is

ready to print from, but this is a mistake. There is a great

deal of ‘‘ doctoring” that can be done to a photomicrograph

negative that will improve the appearance of the resultant

positive picture. Very often we have a negative that has

very little difference in the printing qualities between the

object and the balsam in which it is mounted. In such cases

the removal of the background is the operation to be per-

formed for its improvement. This is done by scraping away

all the film up to and close around the object, as shown by

the black background in the picture of ‘‘ fetal hand” exhibited.

If a clear white back is desired, then the film is painted over

with ‘‘Gihon’s opaque,” a pigment made for the purpose.

This effect is also shown in several of the pictures exhibited

and in some of the souvenir cards. Sometimes pin holes are

found in the film or a scratch from careless handling ; these

should be painted out with either Prussian blue water color

or India ink, and these spots or scratches should be made of

the same opacity as the surroundings. Very often the circle

of light does not extend far enough to allow the print to be

trimmed as it should. In that case a mat is used. This isa

piece of opaque paper with the center cut out ina circle,

ellipse or any other shape to suit the outline of the object.

This feature can also be noticed on some of the souvenir

cards. I like to use a mat because I can make a record on

the margin of it, giving the exposure, objective and plate

used, with date and the like. This mat I stick on to the glass

side of the negative with mucilage and it always remains

there:

We now come to the printing of the positive, and after

trying all kinds of papers to be procured here and some from

other countries, I prefer the ‘‘ Platinotype” to any, for the

reasons which follow: It is the busy man’s paper, because it

116 PHOTOMICROGRAPHY.

is easily and quickly manipulated ; it is not sticky or soft ; it

does not require the use of ice and a thermometer in the

bath to prevent an attack of ‘‘ green sickness or yellow fever ; ”

also because I think it more artistic for photomicrographs

than shiny, glossy paper; and lastly, every piece will make

a picture sure and without the risk of losing any. This

paper is expensive, but the working of it is so easy, simple

and satisfactory, that if once tried it will surely meet with

favor.

The operations are as follows: Print yntil the picture is

bronzed in the shadows. When ready to develop put it ina

tray or on a pane of glass and: brush the developer over it ;

the picture comes out instantly ; in a few minutes it is ready

to be rinsed in two or three successive baths of water acid-

ulated with muriatic acid, then washed for twenty minutes in

clear water, after which they are hung up to dry, and the job

is done and you have for your trouble a thing of beauty and

a joy forever. They can then be mounted in an album or on

cards, as may be desired.

In conclusion I will say that I advise persons having no

knowledge of photography to practise the same with a view

camera before commencing to make microphotographs. The

knowledge so obtained will be very helpful in the prosecution

of photomicrography.

I shall be pleased to answer any questions that anyone

may wish to ask me, or to describe more fully any point that

I have not made clear. I will also explain by letter any

point of difficulty that may be met with in practice, should

such occur. Address me at Warren, O., and it will receive

my best attention.

SYSTEMATIC PHOTOMICROGRAPHY AND APPARA-

TUS PERTAINING THERETO.

By JAMES B. SHEARER, Bay City, Mic.

Although much has been written upon this most interest-

ing subject, and many papers appear each month in the

scientific journals, it may seem presumptuous for me, an

amateur, to say that not enough stress has been laid upon

the necessity for systematic work in photomicrography, in

order to obtain the best results.

Too often the worker depends upon guesswork in timing

exposures ; is careless in arranging the light so that the field

is unequally illuminated ; gives little thought as to the kind of ©

photographic plate used ; develops with any developer that

is handy or cheap; in fact, pays little attention to the details

that are necessary to produce fine negatives.

Having once made a correct exposure, one ought to be

able at any time to duplicate it, or make an approximately

correct one for any similar object, under the same or similar

conditions and combination of lenses and light. It is for

the purpose of teaching beginners, or any who are willing to

be taught, how this may be accomplished that the writer has

presented this short paper.

Experience, and many failures have fully demonstrated

that much valuable time would have been saved, and often

great annoyance avoided, if proper data of former exposures

had been preserved and at hand in convenient form for ready

reference. Suppose one wished to make a photomicrograph

of a histological slide stained with borax carmine, using a

one-fourth objective, two-inch eye-piece and a magnification

of 300 diameters, and when all had been arranged to the

118 JAMES B. SHEARER:

satisfaction of the operator it was found that the photo-

graphic plate was thirty inches from the slide, the lamp four-

teen inches, and the Abbe condenser, with pin-hole stop,

one-eighth inch from slide ; how simple it would be to look

over previous data and find an exposure of another slide,

stained red, and same combination of lenses and light used.

We would then have a sure guide as to time of exposure,

and even with different lenses one would have an approxi-

mate guide.

With this object in view, some years ago, the writer had

a book of forms prepared to enter and preserve such data,

which is as follows :

No.../...,.Name.........magnified......... .. diametenssnams

...-Objective and... .....: Eye-piece.........9alG eee

inch draw tube; using.......light.at..-... inches, ules

éye condenser at... 2... ..<....Inches and... )..0 eee

denser with: :.:....7and:..:....stopat.........inewesunsums

slide. Exposed..:.....seconds, minutes on... -. 2 eplates

No........at........imcheés from “object. _ Color omeareec

Peeters NO ALG pis fsa. ve a NWOMMEINCS aris, F<

The advantage to the worker in using such a book of data

is very great, saves much time, not only in making expos-

ures, but also in determining magnifications; for, once

determined, they are always the same for the same com-

bination of lenses at the same distance of the plate from the

object.

Fairly good photomicrographs can be made with ordinary

objectives, but the best work requires the finest lenses,

correct manipulation of the light, proper kind of photo-

graphic plate, right time of exposure and care in the devel-

opment.

Perhaps the writer can do no better than to describe in

detail the method of making a photomicrograph with the

apparatus figured in Plate I.

The object to be photographed having been placed upon

the stage of the microscope, and the latter turned down

SYSTEMATIC PHOTOMICROGRAPHY. II9Q

horizontally to the position shown in Plate II., the operator

seats himself and views the object through the microscope,

centers it, arranges the light so that the field of view is

equally well illuminated, focuses and, if necessary, adjusts

the objective so as to obtain the best visual image possible,

showing the detail he wishes to photograph.

Then, by means of the turn-table shown at L in Plate II.,

the microscope is swung toward and connected with the

front board of the camera by pressing the front board back

until the tube of the microscope is in position to pass

through, when released, the opening prepared for it in the

camera front. :

The focusing string for fine adjustment is then passed

over the milled head of the fine adjustment wheel of the

microscope and placed in the groove prepared for it on the

wheel, the camera back is extended until the desired amplifi-

cation is obtained, and fastened by means of a set screw.

Next the focus is corrected, for distance from object, by

means of a focusing glass held against the screen of the

camera and through which the operator looks at the image

on the screen of the camera while he adjusts the focus, by

means of the focusing rod, D, shown in Plate II., which

extends the full length of the camera bed. The greatest

care should be taken that the side of the screen on which

the image is focused lies in exactly the same plane that the

sensitive film of the photographic plate will occupy when

placed in the plate-holder and the latter adjusted on the

camera ; the plane of the focusing screen should also be at

an exactly right angle to a straight line drawn from its cen-

ter, through the center of the microscope tube, to the center

of the source of illumination.

When the operator is satisfied that all the arrangements

are as perfect as he can make them, he notes in the book of

forms the full data, and determines from previous data of

exposure, that has proven to be correct, the time to expose the

plate. The correct exposure depends upon many circum-

stances: kind of light, distance of light from object, dis-

120 JAMES B. SHEARER:

tance of photographic plate from object, sensitiveness of

plate and many others.

The time of exposure having been determined, the light

is shut off from the object by means of a screen placed on the

sub-stage condenser-arm of the microscope, the plate-holder

placed in position and slide withdrawn. The operator, with

watch in hand, removes the screen and exposes the plate for

the exact time, as predetermined from data-book of exposures.

With this system one can always make a second exposure,

if found necessary, giving a little more or a little less time,

as required, and, keeping in mind the law of light, ‘‘ The

intensity diminishes as the square of the distance,” one can

calculate just what exposure to give for different magnifica-

tions, with the same combination of lenses, provided one

always works with the same light.

The next step is to develop the plate. It is very impor-

tant that a good developer be used. One of the best,

the writer has used, is that of Dr. William M. Gray, of the

Army Medical Museum, Washington, and is made up as fol-

lows :

No. 1.=—=HiydrOChi nn i os pd. .05 5. = oan QO Ne gaues

Soda sulphite Goene eh BO, oes

oe ee az.

No: 2.—-Soda'carbonate .... .°".... .. /400’ grains:

NA BUST eA eC ea ONG Z,

To develop take four parts of No. 1, two parts of No. 2

and sixteen parts of water. It is a slow developer, but gives

great contrast and density. If developing is done in warm

weather make up developer with ice-cold water and keep ice

in the clearing bath. Carry the development far enough ;

most negatives are taken out of the developer too soon; the

exact time must be learned from experience. After the plate

is fully developed, wash and place it in Carbutt’s acid, fixing

and cleaning bath until all trace of the silver has disappeared,

then in running water for one hour. For general work, the

SYSTEMATIC PHOTOMICROGRAPHY. 12

writer has had the best success with the Carbutt orthochro-

matic plate, No. 23; and, when used with gaslight, no change

of focus is necessary on account of visual and actinic focus.

Many are deterred from working at photomicrography on

account of the prevailing idea that the necessary apparatus

is very expensive. Like all other branches of study and

recreation, it may be made very expensive, but really good

work may be accomplished with the cheaper apparatus, if

properly manipulated.

The apparatus, as shown in Plate I., excepting the micro-

scope, can be had for less than $60, so that the claim of

expense ought not to prevent such an outfit being in every

institution of learning in this country, where the use of. the

microscope is taught. A brief description of this apparatus

will not, perhaps, be amiss:

122 SYSTEMATIC PHOTOMICROGRAPHY.

PLATE lI.

Represents the entire apparatus in position for making an exposure.

a. =camera back, carrying plate holder and focusing screen.

-—=camera front.

6. =camera front extension with circular opening for microscope tube.

¢. ==wood support into which curtain pulley is fastened, over which the

upper loop of fine adjustment focusing string passes.

d. =focusing rod extended full length of camera bed.

e. ==spool on end of focusing rod over which the lower loop of fine adjust-

ment focusing string passes.

J. =bull’s-eye condenser.

&. —=Welsbach gas light.

h. —support for microscope stand, around which the lamp-carrier can be

revolved so as to obtain suitable light for opaque objects.

z. =lamp-carrier with scale to show distance of light from object.

j. ==stand supporting camera.

k. sliding support for turn-table with scale to show the distance turn-

table is from normal position.

2. =turn-table carrying support for microscope stand lamp and bull’s-eye

condenser.

m.—curtain pulleys over which focusing string from coarse adjustment

wheel passes on its way to rear of camera stand.

mzt.—=microscope stand.

Po oo :

Fis eae

= its

; a

ait

124 SYSTEMATIC PHOTOMICROGRAPHY.

PLATE Il.

Showing apparatus in position for centering and adjusting object, arrang-

ing illumination, etc.

2.—set screw to fasten turn-table in position.

o.=scale extending full length of camera bed to show distance of photo-

graphic plate from object.

p.=iris diaphragm in microscope tube, just below the eye-piece, to cut off

reflection.

Other lettering same as in Plate I.

126 SYSTEMATIC PHOTOMICROGRAPHY.

PLATE III.

Showing apparatus ready for final focusing on screen of camera.

v.—=pulley over which passes upper loop of fine adjustment string.

s.—=scale on arm of sub-stage condenser, to show distance of sub-stage

condenser from the object.

- Other lettering same as in Plate I. and II.

128 SYSTEMATIC PHOTOMICROGRAPHY.

PLATE IV.

Showing Bausch & Lomb Optical Co.’s professional stand with iris dia-

phragm, a, just below the eye-piece; and scale, 6, on arm of sub-stage con-

denser, to indicate distance of substage condenser from object.

130 SYSTEMATIC PHOTOMICROGRAPHY.

PLATE V.

Showing apparatus for photographing objects in liquid, or any object that

will not bear being placed in a horizontal position.

a. —=set screw regulating height of rod, e.

a\.=set screw regulating height of plate holder.

b. =rubber band fastening black velvet sleeve to microscope tube..

¢. =upright hollow tubing screwed into iron base, /.

e. =iron rod supporting plate holder and adjustable at various heights by

means of set screw, a.

jf. =cast iron base supporting microscope and apparatus.

o. =black velvet light-tight sleeve attached at upper end to frame carrying

plate holder and at lower end around the microscope tube.

p. =removable plate holder.

PHOTOMICROGRAPH VERSUS MICROPHOTOGRAPH.

(Second Note)

A. CLIFFORD MERCER, M.D. E.R. M-S:, Syracuse, N.Y.

In addition to the first note under the above heading,

published in the PROCEEDINGS of 1886, at page 131, I would

like toadd: The word Photomicrograph was first used in 1858.

An account of its origin can be found in the Lzverpool and

Manchester Photographic Journal (now british Journal of

Photography), August 15, 1858, at page 203, and in the same

volume at page 414, and also in Su¢ton’s Photographic Notes,

Vol. III., at pages 205 and 208. Inthe latter, at page 205, J.

T. Taylor writes: ‘‘ By the way, will Mr. Shadbolt (who is

an authority in microscopy), or anyone else, kindly suggest a

suitable name for such magnified pictures? ‘Microphoto-

graph’ wont do, because the name has been given to reduced

pictures.” At page 208, George Shadbolt answers: ‘‘ The

word microphotograph originated, I believe, with myself,

and is applied, I think correctly, to very small photographs,

not to photographs of small objects, which would more cor-

rectly be photomicrographs; but probably a convenient

word for this class of subjects, as well as enlarged copies

generally, would be megaphotographs.”

ASTRONOMICAL PHOTOGRAPHY

WITH PHOTOMICROGRAPHIC APPARATUS.

A. CLIFFORD MERCER, M.D., F. R. M.S., Syracuse, N. Y.

On the twentieth of October, 1892, occurred a partial

eclipse of the sun, which would have been visible in Syracuse,

N. Y., had not clouds interfered. Early in the day, notwith-

standing the overcast sky, I placed my heliostat on a shelf out-

side a south window*. Within the room I arranged a por-

trait lens of eight inches focus and a microscope in the

same axial line**. The substage condenser was removed

and a camera connected with the eye end of the micro-

scope tube. Such sunlight as fell on the mirror of the

heliostat was reflected through the portrait lens. The

portrait lens projected an image of the clouded sun’s disc,

about one-twelfth of an inch in diameter, in the plane usually

occupied by an object on the stage of the microscope. This

tiny image was itself projected by a microscope objective of

an inch and a half focus to form asecond image, two inches

and three-eighths in diameter, on the ground-glass of the

camera. The clouds made sharp focusing impossible. Only

an imperfect focus was obtained. The clock of the heliostat

kept the image steadily on the ground-glass.

During the eclipse sensitised plates were substituted for

the ground-glass. Exposures were made when the clouds

were thin enough to permit. Thus six negatives were

secured. Prints from two of these are submitted with this

paper. In looking at these prints one is to imagine he

looks to the south with east to his left, west to his right,

north overhead and south toward the horizon. In the prints

* Fig 39, page 147, Transactions American Microscopical Society, Vol. XIV., 1892.

** Fig. 38, page 147, Transactions American Microscopical Society, Vol. XIV., 1892.

ASTRONOMICAL PHOTOGRAPHY. 133

the relative positions of the discs of the moon and sun are

reversed from right to left, from west to east. So the first

print (Plate, Fig. I.) shows the moon’s black disc advancing

apparently from the north-east across the sun’s disc, while the

second (Plate, Fig. II.) shows the moon’s disc passing off to

the west.

This is, I believe, the first record of an attempt to use

photomicrography astronomically. All the necessary appa-

ratus could be easily packed in a trunk, possibly in a hand-

box. Such apparatus is suitable for long distance trans-

portation. If an unaided telescope objective were used to

project an image of the size obtained in our negatives, a

focus of twenty-one feet would be required ; and the lens

would have a diameter of about sixteen inches, if made as

such lenses are usually. Such an objective properiy mounted

would result in an instrument nearly half as large as the

great Lick telescope, with its photographic objective. In

other words, by using a portrait lens having a focus of fifteen

or sixteen inches, a size commonly used for ‘‘ cabinets” in

photographers’ studios, instead of the portrait Jens I used,

the apparatus I have described would produce a negative

image equal in size to that produced by the unaided Lick

lens ; or, leaving my portrait lens in place, the same result

could be obtained by substituting for the microscope objec-

tive of one inch and half focus another of about double the

power, one of three-quarters of an inch focus. The Lick

instrument has a tube about fifty feet long and forty-two

inches in diameter, while my apparatus has two tubes less

than one foot long and about one inch and six inches

in diameter respectively. To the smaller tube is attached a

camera with a bellows extending from one to six feet. Sta-

bility and freedom from vibration are comparatively very

easily obtained with the small and short apparatus. The

difference in housing room is great. The difference in cost

is enormous. It is evident that in several respects the pho-

tomicrographic arrangement has advantages over the great

Lick photographic instrument.

134: A. CLIFFORD MERCER :

If, however, we turn to the matters of light and separat-

ing power, the very great superiority of the Lick objective is

seen. The results given in the following tabular comparison

are only approximately accurate, and I have not taken into

account the loss light suffers by absorption as it passes

through glass and by reflection at incident surfaces, the Lick

objective consisting of three thick lenses and the photomicro-

graphic arrangement having more than twice as many, but

comparatively very thin, lenses and the mirror’s reflecting

surface :

Lick

photographic Larger Smaller

objective. portrait lens. portrait lens,

Diameter of objective ....... 33 in. 3.75 in. 2 in.

Eocus of objective... =.) =) or ene SS hONi: 15 in. 8 in.

Focus divided by diameter. ..... 16.66 4 4

Relative value of light in first image. . I 16 16

Size/oisirsthimage. yi eee = : 5.1 in. .1395 in. .0744 in.

Total equivalent focus, 550 inches,

divided by diameter. ...... 16.66 147 275

Relative value of light in final image . I de sty

Time of exposure, eclipse of sun (about) ress Sec. sip SEC. ¢ sec.

Separating powers ks mene wales pen I gig tsiss

The tabular comparison needs no explanation, I think,

excepting, perhaps, the meaning of ‘‘separating power.”

Other things being equal, separating power varies with the

aperture or diameter of the objective. If the Lick objective,

having an aperture of thirty-three inches, could barely show

a certain double star as two distinct stars, it would be impos-

sible for any objective having an aperture of four or two

inches to show such a double star as two distinct stars. A

star apparently single when seen through any objective hav-

ing an aperture of two inches might be seen to consist of

sixteen or seventeen stars in line, almost touching one

another when seen through the Lick photographic objective.

A star apparently single when seen through any objective

having an aperture of three inches and three-quarters might

be seen to consist of eight or nine stars in line, almost touch-

ing one another, when seen through the Lick photographic

ASTRONOMIGAL PHOTOGRAPHY. 135

objective. This power of resolving an apparent single star

into two or more, or of showing the details of sun spots or

other objects, is known as separating power. Notwithstand-

ing the tabular showing, the photomicrographic arrangement

has advantages in some respects as already mentioned ; and

to these should be added the superior correction of aberra-

tions now possible in lenses made of small discs of glass

which are produced in great variety as to optical properties,

a variety not yet realised, I believe,’ in large discs.

ACETYLENE GAS AS THE ILLUMINANT IN

PHOTOMICROGRAPHY.

W. H. WALMSLEY, Cuicaco, ILt.

Ina paper on Photomicrography, read at the meeting of

this society at Ithaca, in 1895, I stated that the lately discov-

ered acetylene light bade fair to be the best of all artificial

illuminants for this work. At that time, my knowledge of it

was limited to the occasional and ofttimes incorrect accounts

of its wonders furnished by the newspaper press. I had

never seen its light, and practically was utterly ignorant upon

the subject. But the descriptions of its extraordinary bril-

liancy, whiteness and steadiness, seemed to infer a high pho-

tographic value, and led me to predict what has since that

recent date been abundantly proven to be absolutely correct.

To be sure, an English scientific (?) journal about that time

asserted that exhaustive experiments showed the light to

possess no photographic value whatever, and that the expec-

tations of those who proposed to use it for the purpose were

doomed to disappointment. It is not the first recorded

instance of expert mistakes. Facts are stubborn things, and

now, when acetylene is being used not only in photomicro-

graphic work, but for making exposures in the daily work of

photograph galleries, it must be conceded that the journal

in question was mistaken in its statement.

A perfect light has been the desideratum of the worker in

photomicrography from the beginning. Direct sunlight

properly controlled and directed is very nearly but not quite

this. It varies greatly in intensity with the season and the

hour of day. It is rarely available in the confined limits of a

city work-room and never at night, the only time when most

of us have leisure to devote to this work. A heliostat and

ACETYLENE GAS IN PHOTOMICROGRAPH Y. sy

other more or less costly apparatus are necessary for use

with it. None but the favored few can ever hope to invoke

its aid with any degree of regularity.

Next in order of perfection, the oxy-hydrogen or lime light

may possibly be placed, though acetylene is certainly its

worthy peer. Provided with a pair of charged cylinders, a

properly constructed jet, and skill in the manipulation of the

apparatus, the photomicrographer has at his command a very

perfect and entirely satisfactory source of light for his work.

But the necessarily considerable cost of the outfit with the

expense of maintaining it, to say nothing of the difficulty or

impossibility of recharging the cylinders, in many localities,

must always restrict its use to a very limited field.

The light of burning magnesium is exceedingly actinic and

useful for photomicrography, permitting very short exposures.

But numerous objections have always prevented its extensive

use. The fumes and heavy volumes of smoke attendant upon

its combustion are very unpleasant, to put it mildly. It is

difficult to determine the proper length of exposures, and the

cost is somewhat of a serious item to many. The electric

arc light is most excellent, but, for obvious reasons, quite

beyond the reach of most of us.

It follows, then, that to the present time, the one and

only generally available light for our work has been that of

the old, familiar, omnipresent coal-oil, kerosene or petroleum

lamp. Far be it from me to say aught against an old friend

upon whose services I have relied for many years. Rather

let me give thanks for the good it has done. Yet it must

be confessed its many faults fully equal its virtues. Its per-

fume is not that of roses nor its temperature suggestive of

coolness on a hot summer evening. Its yellow, non-actinic

rays, though suitable for some classes of subjects, are quite

the opposite with a majority ; requiring prolonged exposures,

tending to a slight fogging of the plate, with increased dan-

ger of a bleared image from movement of the camera or

microscope. Its negatives rarely possess the brilliancy or

crispness of those made by whiter and more actinic lights.

138 W. H. WALMSLEY:

I have made more than a thousand negatives with its aid, but

very few of them compare favorably in these particulars with

those I have exposed under the acetylene light during the

past eight or ten months.

Early in the autumn of last year it was my good fortune

to make a practical acquaintance with acetylene, under cir-

cumstances and conditions which speedily led to familiarity,

and it has continued to be a daily and nightly companion

ever since, with increasing appreciation of its superlative

value for all purposes requiring artificial illumination. Abso-

lute steadiness, light brilliant and white, but utterly devoid

the ghastly whiteness of the Welsbach burner, in fact ‘‘a

chunk of sunlight” (the spectra of the two being almost

identical), no appreciable heat, no odor whilst burning, mod-

erate cost of the apparatus for generating it, with extreme

portability, simplicity, safety and ease of manipulation. and

almost inappreciable expense of maintenance, combine to

render acetylene the ideal illuminant in photomicrography.

It is not my intention in this paper to say aught regard-

ing the manipulation of light, microscope or camera, leav-

ing those subjects to other and ablerpens. Our respected

president, Dr. Mercer, has already published such exhaustive,

yet simple, and admirable articles on these subjects that

nothing original remains for me. Ishould merely quote from

him wereI to enter upon them. Ishall, therefore, speak only

of the light itself. This is so highly actinic that it may be

safely stated, in a general way, that the average length of

exposures are not over one-fifth of those required with the

best coal-oil lamp, in many cases not exceeding one-tenth of

the latter. .

The form and size of burner may be varied at will,

though it should never exceed one cubic foot per hour in

capacity. My most satisfactory work has been done with

burners of one-tenth that size. To insure perfect steadiness,

it should be enclosed in a metallic case with glass front, as

the acetylene flame is very susceptible to draughts of wind.

I have here four different arrangements of burners and cases,

ACETYLENE GAS IN PHOTOMICROGRAPH Y. 139

all of which have proved extremely satisfactory. The first is

a Russian iron box, 4 by 4 by 2 inches, with open top and

bottom, the front of glass and the whole carried on an

upright rod, to which it can be secured at any desired height

above the table. The burner is of one-foot capacity, set

edgewise to the glass front, affording a very brilliant and

powerful light. The second consists of three pencil-like

flames set in line one behind another, each having a metal

diaphragm in front with an opening of one centimeter. These

being set in one line, an intensely brilliant light of great

depth is obtained with a very small consumption of gas. For

the general idea embraced in this arrangement I am indebted

to Dr. G. M. Sternberg, Surgeon-General, U. S. A., who

used it a number of years ago with ordinary street gas, and

described it in his well-known and valuable work on Photo-

micrography.

The third arrangement is simply one which I originally

designed for a microscopic illuminator, but which has proven

in practice to be still more valuable for photomicrography.

It consists of a burner of about one-eighth cubic foot capacity,

set in a small metallic casing, with front closed by an ordinary

glass microscope slide, which can be removed or replaced at

a moment’s notice, if broken. The glass may be dispensed

with if desired. Its only use is to guard against possible

draughts and to insure absolute steadiness in the flame. The

interior of the case may be whitened by plaster-of-Paris or

coated a dead black, at will. I preferthe latter. This little

lamp is carried upon an upright, with adjustments for height

and inclination. The light is exceedingly brilliant, abso-

lutely white and the consumption of gas almost infinitesimal.

A modification of this lamp, suggested by Hon. A. A. Adee,

of Washington, is alsoshown. In this, the glass slip front is

replaced by a blackened strip of brass, with an opening of one

centimeter opposite center of the flame. It is very satisfac-

tory in use, but I have not found it to be any better than the

plain glass slip.

My own practice is to render the light monochromatic by

140 W. H- WALMSEBY :

means of a cobalt blue cell placed in substage of microscope.

If both focusing and exposure be made under this light, I

think there can be no doubt of superiority in sharpness of

definition and crispness in general effect of the negative.

The length of exposure is somewhat increased, but not to

any great extent.

Among the many advantages of acetylene not the least is

the absence of appreciable heat attending its use for our pur-

pose. Noone who has attempted to make a photomicrograph

by the light of a coal-oil lamp on a warm night has failed to

be sensibly impressed with its fervid qualities ; a good friend

indeed, but rather too warm forthe season. The small area

of the acetylene flame and limited consumption of gas render

it an essentially cool one, and entirely odorless as well.

The crowning advantage of acetylene, however, is its

absolute uniformity. Sunlight varies under differing condi-

tions, as is well known. So do all artificial illuminants hith-

ertoinuse. The so-called standard candle power is a delusion

andasnare. It has been tolerated so long as the unit in light

measurements simply because nothing better has hitherto been

available. But it seems to me that in acetylene we have the

long hoped for and perfect standard. This gas seems to be

staple (924 parts of carbon to 7} parts of pure hydrogen),

whether generated from calcium carbide, yielding four cubic

feet or less to the pound, or the very richest, of more than

six cubic feet. Given a burner, a known capacity, say one

consuming a cubic foot per hour under a predetermined and

uniform pressure, for instance, of two inches of water, the light

produced would always be the same, no matter whence or by

whom. It would thus seem to be a very simple matter to

fix upon a burner of suitable capacity and the best pressure

to give to the world a standard unit of light, from which

measurements could be made with a far greater degree of

accuracy than is possible at present. A two-inch pressure is

suggested, as being about that used in the distribution of

ordinary illuminating gas. It might be also that a burner of

much less capacity than one foot would be better than the

ACETYLENE GAS IN PHOTOMICROGRAPHY. I4I

latter. Careful experimentation by competent persons would

doubtless give certain and reliable results. I am only able

to make the suggestion. I think it is a subject entirely

within the scope of our society, and earnestly recommend

that it take some action inthe matter. It would be a very

gratifying thing for it to have the honor of naming a universal

standard unit of light. In my opinion, this is to be found in

acetylene. Will not our society take hold of the matter in

earnest and prompt manner ?

An important factor in the successful use of acetylene for

photomicrographic as well as other purposes, is the steady,

automatic generation of the gas from calcium carbide, and its

delivery, under uniform pressure Of proper extent, to the

burners in a dry, cool state. These conditions appear to be

very satisfactorily filled by the ‘‘ Monitor” automatic acetylene

generators, manufactured by my house, Walmsley, Fuller &

Co., of Chicago. These machines are extremely simple in

design and construction, easily managed by anyone, perfectly

automatic in operation, and absolutely safe. A nominal

water pressure, never exceeding three inches, is all that can

possibly be used withthem. The holder carrying the carbide

serves also as a gasometer, rising in the tank and lifting the

carbide out of the water, so that generation of gas ceases

when not burning. They are made in many sizes, all how-

ever embodying the same general principles. The gas may

be turned on or off at pleasure and is always ready for use at

a moment’s notice. The smallest size will light one or two

reading lamps, the larger a house or a block. They are

moderate in cost, both as to that of the machines themselves

and the production of the gas. At the present price of calcic

carbide the cost of the light, compared with a given amount

obtainable from ordinary street gas, is about the same as the

latter would be at eighty cents per thousand feet, one cubic

foot of acetylene giving as much light as thirty feet of ordin-

ary gas.

ZOOPHILY VERSUS HOMOPHILY.

PIERRE A. FISH, D. Sc., CornELL UNIVERSITY, ITHAca, N. Y.

The onward march of events, accompanied by new condi-

tions and new methods, has given a much wider significance

to the term vivisection than was formerly attached to it. It

is quite commonly regarded, by those opposed to the prac-

tice, as a method of inflicting, by dissection upon a living

conscious animal, excruciating pain for the gratification of

the operator’s curiosity, or for the exhibition of some experi-

ment already demonstrated and thoroughly familiar.

Technically a man or animal is vivisected when a hypo-

dermic needle is thrust into the skin for the purpose of allevi-

ating the pangs of disease by this form of medication ; while

if any part of the body be crushed or mangled by a blow, as

from a club, resulting in serious injury, there is infinitely

more suffering but not literally vivisection, since the tissues

are not cut but bruised. Nor isthe condition of the victim

taken into account; a serious and prolonged operation upon

an anesthetised animal may result in as little discomfort to

it as the blows or accidental injuries received by any dog on

the streets as an incident in his career; or, in the former

case, if the operation result in death, the end is without pain.

But the issue that now seems to be nearest the surface,

under this really comprehensive term of vivisection, is whether

it is justifiable to utilise, even to their destruction, animals

for the real or probable benefit of mankind, and with this as

the issue, there would be the natural classification of those

who, influenced by genuine sentiments of mercy and a desire

for the alleviation of suffering, band themselves together for

its suppression, especially in animals, on account of the ina-

bility of the dumb beasts to make known certain existing

ZOOPHILY VERSUS HOMOPHILY. 143

-abuses and because of their helplessness in competition with

men. This class of persons would encompass the animals

with so many and rigid safeguards that if really put into

practice many lines of progress would be materially restricted.

For our present purpose let such persons be classified as

Zoophiles—antivivisectionists—and the _ vivisectionists as

Homophiles, the latter advocating not only the essential doc-

trines of the former but something more. Actuated by the

same sentiments of mercy and regard for suffering they would,

when obliged to inflict pain for the general good, minimise it

to the greatest possible extent, by the use of anesthetics or

otherwise.

The practice of vivisection, like the theory of evolution,

does not appeal to the finer esthetic qualities of mankind ; it

is not intended to; it would appeal rather by an array of

self-evident facts to the importance and necessary usefulness

of the practice.

Is it justifiable to sacrifice an animal from a lower level in

the zoological scale for the preservation or benefit of another

animal in that same scale? Nature has already decided that

question by the creation and maintenance of the order of

carnivorous animals, which live on flesh alone, and others

which subsist on mixed diets. If the zoophiles understood

and were enabled to trace the preparation of their animal

food from the living creature to the time it is ready for eat-

ing, would they still exercise as much pertinacity in their

denial of the right to use lower forms for the benefit of the

higher, or is Nature again at fault in fashioning the human

digestive apparatus so that a mixed diet may be enjoyed?

Would not a logical adherence to their cardinal principles

preclude anything but a vegetable diet, and extend even to

the matter of clothing and personal adornment ?

But the answer is made that it is not the aim to legislate

against animal inoculations for the determination of disease, but

to supervise and to eliminate the promiscuous and unnecessary

use ofit. Muchstress is also laid upon the tortures which have

been inflicted upon animals in the past, and these remote

144 PIERRE A. FISH:

instances, although exceptional when the vast number of

experiments are considered, are resurrected and represented

as being in common usage at the present day. There is no

practice that may not be abused. Are the principles of the

Christian religion, upon which so large a portion of the civi-

lised world depends for encouragement and support during

the battle of life, to be undermined because long years ago

there were certain enthusiasts whose zeal permitted them

to inflict the most excruciating, cruel and unparalleled tor-

tures upon their fellow-beings ‘‘In His Name”? Is the

future saving of human life, the saving of vast sums of money

by the preservation of the lives and eradication of disease

in domesticated animals, and the search for the truth

which elevates to a higher plane of civilisation to be retarded

by the misdeeds of past offenders? Will statistics confirm the

generalised statement that vivisection tends to brutalise the

operator? Such an accusation is not brought against a sur-

geon in the performance of his duties. Wherein lies the

great difference in the degree of vivisection? How many of

the antivivisectionists have really gone beyond the first shud-

der at the thought of the existence of pain and appreciated

the fact that life itself is a struggle for existence, and that

the perception of a greater or less amount of pain, under

ordinary conditions, is a circumstance in the career of every

living creature ?

The vivisecting experiments of Galvani have illumined not

only the scientific world, but the material world as well. Out

of the crude apparatus of a vivisector have been developed

the wonderful electrical appliances of today. Galvani’s

experiments were the keys which unlocked the doors of

ignorance, not only as to certain physiological phenomena,

but the manifold mysteries of the uses of electricity, many

of which are still unsolved.

The fact that mature and deliberate judgment may be

exercised in a question of such vital interest has been recently

exemplified in one of the Cantons of Switzerland, where a

measure for the total prohibition of vivisection was submitted

ZOOPHILY VERSUS HOMOPHILY. 145

to the population ad referendum, with the result that 40,000

votes were cast against such prohibition and only 17,000 for it.

In the District of Columbia, it has been proposed to legis-

late against vivisection, or, at least, to regulate it by the

‘maintenance of certain inspectors, who shail at intervals visit

the laboratories or other places where the practice is carried

on.

The bill as arranged is unnecessary, unreasonable, retro-

gressive and reactionary in its tendency.

It is unnecessary, because the great majority of vivisectors

are intelligent, earnest and humane gentlemen, whose object

in animal experimentation is to suppress and prevent the

occurrence of disease, or to add some new fact for the wel-

fare of mankind.

It is unreasonable, in that it advocates a system of espion-

age in which the inspector may be a person igngrant, unskil-

ful and unappreciative of the object to be investigated or of

the methods employed therein. It is manifestly unfair to

permit such a person to officiate as censor, and is a malicious

insinuation against the integrity of the investigator.

It is retrogressive, because it prevents further research;

medical and biological sciences can progress only through

experimentation.

It is reactionary, because in the effort to encompass the

animals with so many safeguards their use for the real benefit

of mankind is lost sight of, and one should be reluctant to

assume that the antivivisectionists love animals more and their

fellow-beings less.

Pain is an adjunct of life, and its merciful infliction upon

lower forms is not only justifiable but necessary when it may

alleviate human suffering. Humanity is above animality and

as long as Nature endows living animals with sensitive tis-

sues, just so long will pain exist.

ON THE TEETH OF MAZODUS.

EW. CLAY. POWE, BA) Dise:, baGss, AKRon;, OIG:

On the top of the Berea grit, as it occurs at Berea, lie

about twenty feet of very dark shale, in which occurs a great

profusion of certain fossils, especially Lingula melie and

Discina Newberryt. With these are some fish remains, and

in the lowest portion are the-large, flat, pavement teeth which

were named J/azodus by Dr. Newberry in his Paleozoic

Fishes of North America. They evidently formed the

mouth armor of some paleozoic shark of comparatively large

size, some of the teeth exceeding two inches in diameter.

The great size and good condition of these teeth, which

are all that we yet know with certainty of the fish, render

them good material for microscopical investigation, and I

propose in this note to give the results of my examination so

far as it has yet gone.

The vertical section of the tooth shows a loose mineral

structure permeated by canals, presenting the same appear-

ance as those in bone. They run, on the whole, vertically

through the tooth, but branch and anastomose with such

frequency that the whole structure is penetrated or honey-

combed with them. Radiating obliquely from these into the

solid tissue are numerous canaliculi running in directions

determined by that of the section and branching as they

diverge from the canal and from each other.

No lacune are present and if the canaliculi anastomose

they unite with those coming from other canals—a structure

quite common in the teeth of fishes.

In the lower portion of the tooth the direction of the

canals is so irregular that little appearance of parallelism can

ON THE TEETH OF MAZODUS. LAy

be detected. The base has a loose spongy texture, gradually

becoming more firm and regular upwards.

Traces can be seen in the lower part of the tooth of an

irregular laminated structure in the solid matter, like that in

the Haversian system of bone, but toward the summit the

structure becomes much more regular and the somewhat

wavy striation of dentine is evident. Through this dentine,

however, the canals extend with nearly the same frequency

as below, and the radiating canaliculi accompany them every-

where. This portion of the tooth has been less deeply

stained during mineralisation, and thereby betrays a denser

nature than that of the lower portion.

Mazodus, therefore, presents a structure very like that of

Cladodus, which I described in a paper before this society

at Madison, in 1893. It shows what we may call a dentary

tissue, which is not the differentiated tissue composing the

teeth of the higher animals, and which does not show evena

well marked dentine, though an approximation to that form of

tissue is discernible. But the passage of the canals through

it makes its appearance very different from that of typical

dentine.

It is further to be noted that as the canals run completely

through this outer layer they open on the external surface of

the tooth, where their mouths give a pitted appearance to

the fossil, often visible without a lens. It is not easy to

correlate them, therefore, with Haversian canals, which are

always lined with periosteal membrane and never detail upon

an external surface. What purpose was accomplished by

their presence in the superficial layer it is not easy to see.

The teeth seldom show signs of great use, though their pur-

pose was probably the crushing of shells, a task likely to wear

or even to break them. Deep scratches, however, are not

uncommon. They were not, probably, renewable after loss

or injury, as are the cutting teeth of the sharks, and hence

their loose and spongy structure is the more remarkable.

The teeth present no trace of enamel, nor have I found

any substance deserving the name on any paleozoic tooth

148 ON THE TEETH OF MAZODUS.

that I have examined. Should this be generally true, then

the introduction of the hardest material in the animal body

is of comparatively late date. At the same time, its absence

would indicate some difference in the development of the

teeth, for the enamel is a product of the ectodermic layer,

while the dentine and its analogue are of mesodermic origin.

It would then follow that the involution of the ectoderm

by the development of the enamel organ did not take place

among the early sharks.

The literature within my reach does not enable me to

ascertain how far investigation has proceeded into the history

of the evolution of the teeth in existing sharks. This matter

has received much attention among the higher animals, but

our knowledge of dental evolution and development in fishes

is as yet very incomplete.

The facts here given show that Dr. Newberry’s original

description needs a slight correction if his words are inter-

preted in their strict sense. Hesays: ‘‘ They (the teeth of

Mazodus) are composed of dense enamel-like tissue through-

out, with no division into crown and base, one enamel and

the other bone, such as we find in all known crushing teeth of

elasmobranch fishes.” So far from being ‘‘enamel-like,”

save perhaps superficially to the naked eye, these teeth are

composed of a very spongy dentinal tissue, whose traversing

canals reach to the very surface, and which, therefore, differs

radically from the close, fine, crystalline structure of real

enamel. And further, so far from being an exception to the

rule among elasmobranch fishes, they are in full accord with

it. In whatever cases I have examined the teeth of fossil

sharks I have found them uniformly composed of this loose,

unenamelline tissue and a true enamel conspicuously absent.

I need scarcely add that this remark refers to paleozoic times

only.

150 ON THE TEETH OF MAZODUS.

BiG el

Mazodus tooth.

Transverse section, showing canals and canaliculi.

1g UL

Mazodus tooth.

Longitudinal section, showing dentine and canals.

ON THE STRUCTURE OF SOME PALEOZOIC SPINES

FROM OHIO.

EW. CLAY POLE Bs Aj 5Canb. G.S:, AKRON, Ono:

In the TRANSACTIONS of the American Microscopical Soci-

ety for 1893, I gave some account of the structure of the teeth

of the cladodont sharks of Ohio, as found by Dr. Clark in

the Cleveland shale of Cuyahoga county. In the present

paper I will give a few details of the structure of some spines

and teeth from the same field, but from a rather higher hori-

zon, the lower carboniferous.

Overlying the Cleveland shale in which the former species

were found is the Berea grit, the lowest of the sandstones of

the carboniferous system in Ohio. It is not usually rich in

fossils, but its topmost layer at Berea is a solid bed of iron

pyrites, about two inches thick, and scattered over this, or

imbedded in it, lie numerous spines of different kinds, the most

abundant of which is one that was described by Dr. New-

berry, in his work on the Paleozoic Fishes of North America,

as Ctenacanthus angustus. These spines are, of course, in a

somewhat imperfect condition, owing to the nature of the

preserving medium, but the characters are recognised with

little difficulty. It is not improbable that more than one

‘species of Ctenacanthus may be present, as species are at

present defined.

The spine examined is rather long and slender, gracefully

curved, laterally flattened and denticulated along its front

edge. In all probability it formed the foremost ray of the

dorsal fin of one of the sharks of that time. It is deeply

furrowed at the back near the base and was set in the flesh

without bony attachment, just as in the spiny sharks, such

as the picked dog-fish of the present day. A transverse

152 ON THE STRUCTURE OF PALEOZOIC SPINES.

fracture shows that the hollow at the base is continued up

through the spine as a tubular cavity, which simulates the

medullary cavity of bone, but has no true analogy with it.

This cavity is, of course, now filled with pyrites, and shows

dead-black in the field of the microscope. The hard tissue

surrounding this medial cavity is homogeneous and pene-

trated in all parts by large and numerous Haversian (?)

canals. These run, in the main, parallel with the length of

the spine, but they inosculate continually so as to form a

complete network of minute passages, which are also clogged

with pyrites and show in strong contrast against the reddish

ground of the tissue. So numerous and large are these chan-

nels that in many places the empty spaces exceed the solid

matter of the spine, which must consequently have been very

light in comparison with its size, and therefore better adapted

to its duty.

The ground mass of the bone is perfectly solid, without

lacune or canaliculi, and shows in this point no resem-

blance to true bone. Traces of aconcentric arrangement

around the canals (in what may be called the Haversian sys-

tems), indicating the method of formation, may, however, be

detected.

The structure, evidently, is more like that of tooth than of

bone. This is what might be expected, as the spine must

be classed with the dermal appendages rather than with the

skeleton. The teeth, spines and scutes or scales that more

or less cover the bodies of fishes are all special developments

of the papillez of the skin, and though in some kinds of teeth

lacune are apparently present it is more than doubtful if they

are of the same nature as the true lacune of bone, except

when they are found in the cementum, which is merely the

calcified periosteum of the alveolus.

The occurrence of Ctenacanthus angustus in the same

horizon with J/azodus, and the absence of other forms, leads

the geologist to suspect that they belonged to the same fish,

and in that case one of the names will become a synonym.

This, however, belongs to the field of paleontology.

154 ON THE STRUCTURE OF PALEOZOIC SPINES.

ree ale

Spine of Crenacanthus angustus—Nby.

Transverse section, showing Haversian canals.

Fie. II.

Spine of Crexacanthus angustus—Nby.

Longitudinal section, showing central cavity and canals.

THE ROTIFERA OF SANDUSKY BAY.

Dos) KELEICO LD Pa. Dy Eke Nios. COLUMBUS OF

In order that the title and the substance of my paper may

not appear to be out of all reasonable proportion, permit me

an introductory word of explanation. In consequence of the

liberality of the Trustees of the Ohio State University, I now

have a Lake Laboratory, located on Sandusky Bay, where I

have spent a part of the present summer vacation and where

I expect to spend more or less of subsequent ones. The

study of the Rotifera of the bay will be continued from year

to year, and it is my purpose to report from time to time the

work accomplished. This list, then, is only a partial one,

giving such species as have been identified, their habitats,

etc., with descriptions of such as appear to be new.

While living at Buffalo it was my pleasure to study Rotifera

somewhat at the eastern end of Lake Erie. Very few of my

notes have been published, but the resumption of study at

Sandusky renews acquaintance with many old friends, which

it has been a delight to meet and greet. This charming

group is one of deep interest everywhere, but in no situation

may one expect to find a richer rotiferal fauna or one with

more unique forms than in our Great Lakes.

Since the brief papers read by myself on these creatures

at the Cleveland and first Pittsburg meetings some work has

been done and published on Rotifera of the Great Lakes,

notably by Mr. H. S. Jennings. His paper, A List of the

Rotatoria of the Great Lakes and Some of the Inland Lakes of

Michigan, will often be referred to by the name of the author

in the course of my remarks.

156 D.S. KELLICOTT :

Sandusky is situated on a peninsula, having the wide

glacial estuary of the Sandusky river, known as the West

Bay, on one side, and on the other the East Bay, which is a

shallow body of water cut off from the lake by a sandbar,

known as Cedar Point, several miles long. This East Bay is

the site where the work of this paper was done. The bay

extends to the southeast several miles, ending in extensive

marshes, where a variety of marsh plants abound in great

profusion. Moreover, there are sheltered ponds and marshes

on the Point, which are simply bodies of water resting

in basins of sand, maintained at a constant level by the

influence of the lake. The place appears, therefore, to be

an ideal home of Rotatoria, and the short time thus far spent

in finding them out has not been disappointing.

The systematic arrangement followed is that of Hudson

and Gosse’s Rotifera. References to this work will be simply

by the authors’ names.

FAMILY I. FLOSCULARIADA.

FLOSCULARIA, Oken.

I. Ff. -ornata; Ehrenberg.

Very common on the dissected leaves of Utricularia, on

the under side of leaves of Mymphea and Nelumbium, in the

bay and in the marshes and coves.

I often found the egg placed high in the tube, so that

when the animal retreated it passed below the egg.

2. SF. cornuta, Dobie.

Few of this distinct species were found ; elsewhere, Buffalo

and Central Michigan, I have found it as abundant as ornaza.

3. J Mellsiz,. Kellicott.

In abundance in U¢ricularta growing in a marsh on Cedar

Point. This makes the third station for this beautiful flos-

cule, viz. > Black Creek, Ontario, Canada; ':SidneyjoNew

South Wales, by Mr. Thomas Whitelegge; and Sandusky

Bay, Ohio.

I have again measured an average example, and find sub-

THE ROTIFERA OF SANDUSKY BAY. 157

stantial agreement with the dimensions given in my original

paper,* whilst that of the antipodal form was scarcely half as

large. Again, in regard to the foot, I may say that there is no

attenuated pedicle, but as Mr. Whitelegge says, ‘‘A short

[and stout] immovable stalk, which is not affected when the

animal retracts or extends ;” the three ring-like protuberances

at the end of the foot, just above the stalk, described by him,

I am unable to make out.

4. F. campanulata, Dobie.

Exceedingly abundant in the quiet marshes, found on a

variety of plants, but most numerous on young branches of

Utricularia.

5. F. ambigua, Hudson.

With the preceding ; much less numerous.

6. Ff. mutabilis, Bolton.

Few taken in the skimming net and by straining water

from the faucet.

FAMILY IE) MELICERTADZ.

MELICERTA, Schrank.

7. M. contfera, Hudson.

Very abundant, especially under floating leaves of Velum-

dium. Its tubes were often found in clusters similar to those

of MW. ringens. I have found groups of tubes fully one-eighth

of an inch long and containing not less than twenty-five

tubes.

8. MW. flocculosa, n. s.

Lobes wide, expanding fully twice the greatest width of

the stout body; antennz very short ; tube gelatinous, with

much adherent floccose, thus resembling a dense tube of a

floscule.

Two individuals of this fine species were found under

floating leaves of Nelumbium luteum. It appears to be closely

related to MZ. tudicolaria. It differs from that species in

* TRANSACTIONS of this Society, Cleveland meeting, 1885, page 48.

158 Di Ss AKPLEICOEN:

having a much stouter body, the lobes relatively narrower,

in having a spatulate chin and very short antenne ; ¢ubzcola-

ria has these organs very long. The tube appears to have

the floccose incorporated with the gelatinous matter. This, I

think, is done by accumulating it in the ciliated cup and

placing it on the margin and surface of the tube, much as

(Ecistes longicornis may be seen to do.

One characteristic, large, brown egg was noticed in the

tube of the largest one.

The size is large, but the record of its exact dimensions

was lost.

LIMNIAS, Schrank.

g. L. ceratophylit, Schrank.

Very few were found. I have found this abundant in the

Niagara River.

10. JL. Shiawasseensis, Kellicott.

Very rare.

11. JL. annulatus, Bailey.

Very common on aquatic plants in coves and marshes.

CEPHALOSIPHON, Ehrenberg.

12:- G. dimntas, Ehrenberg:

Abundant on Utricularia and water-lily pads. ©

CECISTES, Ehrenberg.

13. G. crystallinus, Ehrenberg.

Not uncommon.

14. CG. longicornis, Davis.

Not uncommen.

I find that this interesting rotiferon, as I reported several

years ago, has a well-formed cylindrical or somewhat vase-

shaped tube, covered with floccose, arranged in transverse

lines, giving the striated appearance alluded to by Mr. Davis.

When the focus is deeper the tube looks like a piece of ani-

mal’s hide with its long shaggy hair. This disposition of the

material is doubtless accomplished by means of the stout

THE ROTIFERA OF SANDUSKY BAY. 159

ciliated chin. Mr. Jennings finds the tubes of definite

form.

The corona appears to me to be more strongly bilobed

than the extant figures represent it. The tube closes when

the animal retires within, and as it cautiously returns, ove

antenna, partly folded over the front, precedes, much like

the antenna of C. /émnzas, although without the exploring

motion of that species; later the other long antenna unfold

and extend its sensitive sete.

15. G. mucicola. Kellicott.

Somewhat rare. The gelatinous balls of the alga in which

it lives are numerous enough, and occasionally a rotiferon is

seen protruding or suddenly retreating within its domicile

for protection.

LACINULARIA, Schweigger.

16; ZL. ‘socials, Ehrenbera,

Very abundant on Vymphea and Neluimbtum. I have

seen colonies a fourth inch across.

MEGALATROCHA, Ehrenberg.

17. M. alboflavicans, Ehrenberg.

With Lacinularia, less common, colonies smaller.

CONCHILUS, Ehrenberg.

rs. 6. volvoz, Ehrenberg:

Few colonies seen from marsh-water.

FAMILY III. PHILODINAD.

PHILODINA, Ehrenberg.

19. P. roseola, Ehrenberg.

Common on all sorts of aquatic vegetation.

20. P. cttrina, Ehrenberg:

Not uncommon, with the last.

21. P. megalatrocha, Ehrenberg.

Common.

22.\5 PYiaculcaia;

160 DS KEE eiCOmit:

Not uncommon among roots of duck-weed in sheltered

situations.

ROTIFER, Schrank.

23. R. vulgaris, Schrank.

Abundant.

24. WR. tardus, Ehrenberg.

Among alge.

25. &R. macroceros, Gosse.

Common in the forks of U¢ricularza partly surrounded by

debris.

26. R. macrurus, Schrank.

Many seen.

CALLIDINA, Ehrenberg.

27. “iC. elegans, Ehrenbere:

Several taken among weeds in the marshes. It was so

restless that I do not feel sure of the identification.

FAMILY VI. ASPLANCHNAD-.

ASPLANCIINOPS, de Guerne.

28. <A. myrmelio, Ehrenberg.

Few were collected in marsh-water. I do not find the

ovary so large as figured, but of characteristic horse-shoe

shape. I find the trophi to agree well with the descriptions.

FAMILY VII. SYNCHATADA.

SYNCHATA, Ehrenberg.

29. S. tremula, Ehrenberg.

Rare in marsh-water. I am not wholly satisfied that it

is tremula.

FAMILY VIII. TRIARTHRADA.

POLYARTHRA, Ehrenberg.

30. P. platyptera, Ehrenberg.

Common in water-supply and among aquatic plants.

THE ROTIFERA OF SANDUSKY BAY. 161

TRIARTHRA, Ehrenberg.

31. TZ. longiseta, Ehrenberg.

Not uncommon in the water-supply. The sete of one

were found to be more than three times the length of the

body.

FAMILY IX. HYDATINADZ.

PLa&SOMA, Herrick.

32. P. lenticulare, Herrick.

A few dead ones in sediment from water-supply.

FAMILY X. NOTOMMATADA.

NOTOMMATA, Gosse.

23. WN. aurtia, Ehrenbere:

Among growing water-plants in clear water. Several seen.

34. NW. lacinulata, Ehrenberg.

Very common among alge.

COPEUS, Gosse.

ac. .C. cerebrus, Gosse-.

Under Nelumbium leaves.

PROALES, Gosse.

36. P. decipiens, Ehrenberg.

In water from marsh.

37. P. gibba, Ehrenberg.

Not uncommon among roots of duck-weed growing in

shallow pools along edges of the marshes.

28. P. sordidd, Gosse:

Same localities as the preceding species.

FURCULARIA, Ehrenberg.

39. F. longiseta, Ehrenberg.

Marsh water.

Numerous species of this family besides those mentioned

were found and studied, but the identification was not satis-

factory. They may wait for a future opportunity.

162 DS. RELLICOLRT:

FAMILY XI. RATTULIDA.

MASTIGOCERCA, Ehrenberg. .

40. M. carinata, Ehrenberg.

Among alge. I have not found the ruby-colored variety

common at Corunna, Mich., and which Jennings found in

Rake St Clare:

41. M. bicornis, Gosse.

Among duck-weed along shore. Not common.

42. WM. lata, Jennings.

Rather common in filterings from water-supply.

RATTULUS, Ehrenberg.

43. R. sulcatus, Jennings.

Few under floating Welumbzum leaves.

CCELOPUS, Gosse.

44. C. porcellus, Gosse.

Common.

45. C. tenuior, Gosse.

Common in sediment from marshes.

FAMILY XII. DINOCHARID#Z.

SCARIDIUM, Ehrenberg.

46. S. longicaudatum, Ehrenberg.

Very common.

STEPHANOPS, Ehrenberg.

47. S. lamellaris, Ehrenberg.

Common among water drained from duck-weed, and

among alge.

48. S. chlena, Gosse.

Several seen among U¢ricu/aria from marsh.

FAMILY XIII. SALPINADA.

SALPINA, Ehrenberg.

49. S. brevispina, Ehrenberg.

Very common among bladderwort and duck-weed.

THE ROTIFERA OF SANDUSKY BAY.

50. S. ventralis, Ehrenberg.

Common with the preceding.

FAMILY XIV. EUCHLANIDA.

EUCHLANIS, Ehrenberg.

51. &. dtlatata, Ehrenberg.

Common among shore plants.

52. &. triquetra, Ehrenberg.

With the preceding.

FAMILY XV. -CATHYPUAD.

CATHYPNA, Gosse.

53.- C. luna, Ehrenberg.

Common among alge in quiet pools.

DISTYLA, Eckstein.

54. D. Ohtoensis, Herrick.

Not common ; among roots of Spzrodela polyrrhiza.

MONOSTYLA, Ehrenberg.

55. MW. lunaris, Ehrenberg.

Common.

56. M. bulla, Gosse.

Common among vegetation everywhere.

57. MM. quadridentata, Ehrenberg.

Less common than the last ; found with it.

FAMILY XVI. COLURID.

Co.Lurus, Ehrenberg.

58. C. deflexus, Ehrenberg.

Very common.

METOPEDIA, Ehrenberg.

59. M. lepadella, Ehrenberg.

Abundant.

163

164 THE ROTIFERA OF SANDUSKY BAY.

60. M. solidus, Gosse.

Rare.

61. WM. oxysternum, Gosse.

Few seen.

FAMILY XVII. PTERODINADZ.

PTERODINA, Ehrenberg.

62. P. patina, Ehrenberg.

Common.

63... P. refiexa, Gosse.

Rare.

FAMILY XVIII. BRACHIONIDA.

BRACHIONUS, Ehrenberg.

64. 8B. mtlitaris, Ehrenberg..

Very common, in water-supply and among plants along

shore.

NoTeus, Ehrenberg.

65. NW. guadricornis, Ehrenberg.

Few in shallow pools mantled by Lemna.

FAMILY XIX. ANURAAD.

ANURAA, Gosse.

66. <A. cochlearis, Gosse.

Extremely abundant in water-supply of Sandusky.

67. <A. stipitata, Ehrenberg.

Abundant in the water supply of Sandusky.

Nearly or quite as abundant as the last ; readily separated

by its shape as shown by Gosse and by the tessellation of the

dorsal shield. In A. cochlear?s there is a dorsal keel extending

from posterior spine to the cervical plate; in the other, the

two middle rows of dorsal plates are alternately and irregu-

larly hexagonal and pentagonal, breaking the dorsal ridge.

THE REQUISITES OF A PURE WATER-SUPPLY.

WILLIAM C. KRAUSS, M.D., F. R. M. S., BurFato, N. Y.

In the rapid growth characteristic of our American cities

and villages, the question of adequate water supply becomes

one of the great and pressing needs for early consideration, and

in many communities natural or artificial sources are selected

more with the view of supplying guantzty rather than guality

of water. Even should these sources have been of unques-

tioned purity the improper disposal of the city’s sewage,

through the stupidity or carelessness of the proper officials,

may have exposed the water to contamination and rendered

it in time dangerous and polluted.

Another phase of this question is seen in cities drawing

their supply from natural waterways upon which they may be

located, in the slowly and gradually decreasing standard of

purity, due to the refuse-disposal of rapidly growing cities or

villages situated farther toward the source of these same

water-courses.

This important and vital question of pure water supply

and means of retaining it, is just now attracting timely atten-

tion by scientists and engineers, especially in the Middle and

Eastern States of our Country. The ravages and immense

cost of epidemics through water-borne or water-bred specific

germs have awakened many communities toa proper sense of

the impending and threatening danger awaiting them, and

are devising ways and means to avert the inevitable results.

Just what a pure supply means is hardly open to much

debate and may be summed up in five propositions, as fol-

lows :

1. That the water-supply of any city or village should

166 WILLIAM C. KRAUSS:

not in any possible way be liable to pollution or contamina-

tion from the sewage of any other community.

2. That the sewage of a city should not be emptied into

any water course not having a current of three to five miles

per hour, and then the sewage entrance should be at a dis-

tance one mile or more from the intake. .

3. When the water-supply of any city or village is a navi-

gable stream the water should be sand-filtered before pumped

into the city reservoirs or water mains.

4. That for ordinary drinking purposes the water should

not be taken in its primitive or raw state, but be either filtered,

boiled or distilled and aerated.

5. That not only chemical but bacteriological examina-

tions of the water should be made, at least once weekly, to

determine its character as a safe or dangerous water for

domestic use, and where contamination is shown to exist, the

services of an engineer be enlisted to detect, if possible, the

cause and origin of such contamination.

This last proposition is the one to which I wish to call the

attention of the society today. Who is to decide whether a

water is potable, the chemist or the bacteriologist ? Up to

within a few years ago a chemical examination of water was

deemed sufficient to decide its potability, and upon the decree

of the chemist the water was either accepted or rejected.

The chemist was generally able to detect the presence of

decomposing organic matter, either vegetable, animal, or

both, which in his analysis was indicated by the presence of

ammonium compounds and the oxygen consuming power of

the water. The ammonium compounds, particularly the

albuminoid ammonia are usually the result of putrefactive

fermentation of nitrogenous matter, and water of high purity

should contain from none to .041 parts per million, while in

impure water it ranges from .082 and over.

THE REQUISITES OF A PURE WATER-SUPPLY. 167

The consumption of oxygen by the water and the forma-

tion of carbon dioxide occurs during the fermentation of small

quantities of organic matters in the water, and provides a

most delicate indication of the presence of such matters ina

suspected water. The following proportions are given by

Frankland and Tidy, as the basis of interpreting the results of

this method :

High organic purity... . . 0.05 parts per million (in three hours).

Medinm! purity ©. 5). 2s. = 0.5 to 1.5

iDsoprilayg Gaul ae peti: pean eee LE Ne) ol

PMpPUTC sn <<) 5) sex. 2.1

The presence of chlorine and phosphoric acid must also be

regarded with suspicion when found in large amounts, as they

are constant ingredients of animal excretions. Surface waters

ordinarily contain but a few parts per million.

The chemist, then, is only able to say that a water contains

organic matter in the process of fermentation, but cannot say

how virulent or innocent are these destructive agents. It is

now generally accepted that organic matters, which by ohne

means or another find their way into surface waters are oxi-

dised and eventually reduced to simple substances by the

operations of microorganisms, and not by mere chemical

changes independent of them. In other words, the oxida-

tion of impure, polluted water is the result of bacterial activ-

ity, and the decree of the bacteriologist is now imperative in

deciding the pathogenic or non-pathogenic character of the

bacteria.

The number and variety of species present in water from

any given source will depend upon conditions relating to the

amount of organic pabulum, the temperature, the depth of

the water, the fact of its being in motion or at rest, and its

pollution from various sources.

The water from artesian wells contains no bacteria, while

that of sluggish streams, lakes and rivers receiving the sew-

age of large cities contains millions of colonies per cubic cen-

timeter. Authorities consider a water having 250 bacteria

per cubic centimeter, orless, as entirely safe and usable.

168 WILLIAM C. KRAUSS:

It is now generally recognised that the mere enumeration

of the number of colonies which develop from a water under

investigation is not a sufficient indication upon which to

found an opinion as to its potability. Of course, the greater

the number of colonies the more organic pabulum is present for

these microorganisms. The bacteriologist is not able as yet

to give any definite idea of the amount of such organic mat-

ter, while the chemist is able to do so with considerable pre-

cision. But the bacteriological examination may prove to be

of great value if it succeeds in demonstrating the presence of

certain pathogenic bacteria, and in thus preventing the use

of adangerous water. Moreover, the number of colonies is

an index of the probable quantity of organic matter which

may come from a dangerous source; and the dangerous

pathogenic bacteria are not only likely to be present in such

water but they can more readily multiply in it. (Sternberg. )

Sternberg gives the number of varieties of non-pathogenic

micrococci found in water as thirty, pathogenic micrococci,

two—the Staphylococcus pyogenes aureus and the Micrococcus

Biskra. Of the non-pathogenic bacilli seventy-nine vari-

eties have been found, while of the pathogenic bacilli sixteen

varieties, including the bacillus of typhoid fever, of cholera,

and the Bacillus coli communis. These three varieties are

the most important findings possible of a bacteriological

examination and are positive proof of the presence of alvine

dejections in the water.

The continued presence of typhoid fever in a municipality

is as inexcusable as vermin in a modern dwelling, and indi-

cates a degree of shiftlessness and apathy not consistent with

modern American views and energy.

Lake Erie, the water supply of Buffalo, also of the cities

of Toledo, Cleveland, Dunkirk, Erie, Ashtabula, is subject

to periodical upheavals, due to its shallowness and the strong

west and northwest winds occurring during the winter and

spring months. Asa result we have roily water five or six

months of the year, beginning with November or Decem-

ber and lasting until May or June. It will be interesting,

THE REQUISITES OF A PURE WATER-SUPPLY. 169

therefore, to compare the results obtained by the city chem-

ist and city bacteriologist, both very capable and scien-

tific gentlemen, and see how they agree or disagree, with a

view of determining which is the more trustworthy guide.

These examinations are made daily by the bacteriologist and

monthly by the chemist, under the direction of the health

commissioner :

DECEMBER, 1895.

Chemical Analysis :*

‘‘Organic residue, 3.36 grains per gallon; albuminoid

ammonia, 0.078 parts per million ; oxygen dissolved in four

hours, 0.62 parts per million. Conclusion—Water continues

in excellent condition.”

Bacteriological Examination :

‘« Highest number of bacteria per cubic centimeter, 765 ;

lowest number of bacteria per cubic centimeter, 55 ; average

number of bacteria per cubic centimeter, 225; in reservoir,

10. The bacillus Janthinus was found on December 18th

and 23d, indicating probable filth contamination. Conclu-—

sions— Water is in poor condition.”

During December large quantities of dead fish were found

along the south shore of Lake Erie.

Enteric fever deaths, 11. Death-rate, 11.65 per 1,000.

JANUARY, 1896.

Chemical Analysis, January 28, 1896:

‘‘Organic residue, 2.72 grains per gallon; albuminoid

ammonia, 0.148 parts per million ; oxygen absorbed in four

hours, 0.43 parts per million. Conclusions—This water is in

good condition.”

Bacteriological Examination :

‘‘Highest number of bacteria per cubic centimeter, 3,250;

lowest number of bacteria per cubic centimeter, 195 ; average

* These are taken from the monthly reports of the Board of Health and are the official

figures.

170 WILLIAM C. KRAUSS:

number of bacteria per cubic centimeter, 800. Bacillus Jan-

thinus present on January 3d. At that time and during the

week following the water was in very poor condition. A

gradual improvement is noted.”

Death-rate, 11.68 per 1,000. Enteric fever deaths, 5.

FEBRUARY, 18096.

Chemical Analysis, February 28, 1896:

‘(Organic residue, 1.96 grains per gallon; albuminoid

ammonia, .092 parts per million; oxygen dissolved in four

hours, 0.56 parts per million. _Conclusions—Water is good.”

Bactertological Examination :

‘‘ Highest number of bacteria per cubic centimeter, 8,820;

lowest number of bacteria per cubic centimeter, 60; average

number of bacteria per cubic centimeter, 1,000. Tap water

figures excessive, due to storms, dirty ice and low water in

reservoir.”

Death-rate, 10.61 per 1,000. Enteric fever deaths, 3.

MARCH, 1896.

Chemical Analysis, March 28, 1896:

‘(Organic residue, 3.31 grains per gallon; albuminoid

ammonia, 0.077 parts per million; oxygen absorbed in four

hours, 0.510 parts per million. Conclusions—This water is

in excellent condition.”

Bacteriological Examination :

‘‘ Highest number of bacteria per cubic centimeter, 990 ;

lowest number of bacteria per cubic centimeter, 65; average

number of bacteria per cubic centimeter, 260. In the reser-

voir there were found, on March 2d, 2,205, and on March

13th, 19,790 bacteria per cubic centimeter, due to slush.

Conclusions—The condition of the water is good.”

Death-rate, 11.58 per 1,000. Enteric fever deaths, 4.

APRIL, 1896.

Chemical Analysis, April 28, 1896:

‘‘Organic residue, 2.67 grains per gallon; albuminoid

THE REQUISITES OF A PURE WATER-SUPPLY. IAL

ammonia, 0.032 parts per million ; oxygen absorbed in four

hours, 0.302 parts per million. Conclusions—This water is

’

in excellent condition.’

Bacteriological Examtnation :

‘« Highest number of bacteria per cubic centimeter, 20, 160;

lowest number of bacteria per cubic centimeter, 80; average

number of bacteria per cubic centimeter, 3,000. Conclusions

—Large bacterial contents during this month, due to quanti-

ties of dirty ice. The water is not in good condition, but no

harmful or polluted water organisms have been found.”

Death-rate, 12.67 per 1,000. Enteric fever deaths, 4,

MAY, 1896.

Chemical Analysis, May 28, 1896:

‘(Organic residue, 3.24 grains per gallon; albuminoid

ammonia, 0.088 parts per million ; oxygen absorbed in four

hours, 0.55 parts per million. Conclusions—This water is in

poorer condition than last month. There is evidence of con-

tamination.”

Bacteriological Examination:

‘‘ Highest number of bacteria per cubic centimeter, 18,900;

lowest number of bacteria per cubic centimeter, 230; average

number of bacteria per cubic centimeter, 2,300. Conclusions

—Ice stopped running on May 7th, after which time the bac-

terial contents gradually lowered until the 14th. On this

date and the day following the number increased, due to

wind. At present time (May 26th) water is in good condi-

tion (270 per cubic centimeter).”

Death-rate, 11.40. Enteric fever deaths, 1.

JUNE, 1896.

Chemical Analysis, June 29, 1896:

‘‘Organic residue, 3.97 grains per gallon; albuminoid

ammonia, 0.087 parts per million ; oxygen absorbed in four

hours, 0.659 parts per million. Conclusions—This water

172 WILLIAM C. KRAUSS:

has improved somewhat in quality since the last examina-

tion.”

Bacteriological Examination :

‘‘ Highest number of bacteria per cubic centimeter, 700 ;

lowest number of bacteria per cubic centimeter, 35 ; average

number of bacteria per cubic centimeter, 235. Conclusions

—The water is in good condition.”

Death-rate, 11.79 per 1,000. Enteric fever deaths, 3.

During December, although the organic matter in the

water was small and the number of bacteria correspondingly

so, yet there was found a bacillus which is generally found in

water which has undergone sewage contamination. During

this month there were eleven deaths reported from typhoid

fever. The bacillus of typhoid waS not found in the water,

although repeated examinations were made with this end in

view. It is, however, extremely difficult to detect the

typhoid bacillus, as the following extract, quoted from Rafter*

will prove:

‘*Messrs. Laws and Andrewest state that werking on ordi-

nary London sewage they failed in every case to recognise

the typhoid bacillus, until finally the failures were so numer-

ous that they became oppressed by a sense of mathematical

‘ improbability. Thus the average amount of sewage produced

in London amounts to 200,000,000 gallons per day. During

June, 1894, while the investigation was in progress, 177 cases

of typhoid fever were notified in London, to which may be

added thirteen cases of continued fever, making 190 cases in

all. Adding something for cases not reported and Messrs.

Laws and Andrewes conclude that during June, when typhoid

is by no means prevalent, it may be assumed that there were

200 cases in all. Some of these suffer from constipation and

hence contribute very little fecal matter to the general mass

of sewage. For these and other reasons cited, any estimate

* George W. Rafter, on Lake Erie as a Water Supply, Buffalo Medical Fournal, August,

1896,

t Report on the Result of Investigation on the Microdrganisms of Sewage. By J. Parry

Laws and F. W. Andrewes, 1895.

THE REQUISITES OF A PURE WATER-SUPPLY. 173

of the average amount of sewage contributed daily by typhoid

cases in London must be purely conjectural, but at a reason-

able estimate it is placed at two hundred and fifty millionths

of the whole, and, as Laws and Andrewes point out, every

endeavor is made to disinfect this before it is allowed to pass

into the sewers. The mathematical chances of detecting the

typhoid bacillus in ordinary London sewage are, therefore,

extremely remote. Assuming the typhoid bacillus to be

intimately mixed with the ordinary sewage there would be

only one typhoid bacillus in one-tenth of a cubic centimeter

of sewage at the outfalls.

‘But the investigators only found it possible to work on

one five-thousandths of a cubic centimeter, and this only

when 90 per cent. of the organisms were inhibited by the

addition of 0.05 per cent. carbolic acid and incubation at 37°

ent:

‘These considerations were so discouraging that it was

determined to work on sewage from a fever hospital, and

arrangements were accordingly made to allow the dejections

from forty patients in the Eastern Hospital, at Homerton, to

pass into the hospital sewer for two days without disinfection.

A series of samples were then taken and cultivations made

therefrom at once. Without going further into detail, it may

be stated that from the whole series of sewage taken under

these circumstances only two colonies of the bacillus of

typhoid fever were certainly differentiated. In their summa-

tion Messrs. Laws and Andrewes say :

‘« «We must be content to have shown that in the drain

from the typhoid block of a fever hospital, when the stools

had not been disinfected for two days, a bacillus can be found

which, so far as demonstration can go, is identical with that

believed to be the actual cause of typhoid fever. So far as

we are aware, this important fact has never been previously

demonstrated.’ ”

In January, according to the city chemist, the water was

in good condition, while the bacteriologist again found the

bacillus Janthinus and reported the water to be in ‘‘ very

174 WILLIAM C. KRAUSS:

poor condition ” for the first half of the month and a gradual

improvement the last half. The number of typhoid deaths

decreased to five. In February and March both officials

found the water in good condition, also evidenced by the

death-rate and the typhoid deaths, three and four respectively.

For the months of April and May there exists a disparity

between the two reports, the chemist claiming that the water

was in ‘‘excellent condition ” during May, while the bacteri-

ologist found the water ‘‘ not in good condition,” because of

large bacterial contents. The deaths from typhoid fever

were four—an unusal time for typhoid to be present. For

May the chemist found evidences of contamination, while the

bacteriologist, on the preceding day, considered the water in

good condition, containing on that day only 270 bacteria per

cubic centimeter. In June both officers found the water in

good condition.

Reviewing the opinions of the city chemist and the city

bacteriologist, it is evident that the disparity occurs whenever

the water is in an improper and unhealthy condition, and,

when such is the case, it is only fair to assume that some

error has been committed favoring the water.

The bacteriological examination as well as the chemical

analysis are, therefore, alike necessary in demonstrating the

purity and safety of a drinking water, and neither should be

omitted when the least suspicion exists as to its contamination.

The consumers should be immediately warned of the dangers

of using such water in its raw state, and should be enjoined

upon to make some attempt «at purification, either filtering,

boiling or condensing. This applies not only to those cities

whose water-supply is open to contamination but to every

city having a public supply.

Besides the chemist and bacteriologist, the water depart-

ment of every city, whose supply is liable to contamination,

should have the services of an engineer, whose fame does not

rest upon his theoretical knowledge and bureaucratic propen-

sities, but upon his. practical information of the laws of hydrol-

ogy and hydrodynamics. Such an one, well versed in the

THE REQUISITES OF A PURE WATER-SUPPLY. 175

hydrography of his locality, could almost prognose the condi-

tion of his water-supply and be an important aid to the city’s

health department. As such he would be able to render the

same valuable services, as does the Local Forecaster in

meteorology, and give warning several days beforehand of

marked changes in the quality of the water.

While the chemist and bacteriologist are only able to

detect impurities after contamination, the engineer could

foresee these changes and give sufficient warning, or attempt

to overcome the impending contamination before the city

mains and reservoir are filled with the poisonous liquid.

The question of food contamination and adulteration has

attracted the attention of the lowest tribunal up to the high-

est (Filled-cheese bill of last Congress), and severe laws are

upon the statute book punishing offenders, and yet the water-

supplies of some of our cities are openly and flagrantly pol-

luted and no attempt whatever is made at punishment, partly

because insufficient attention has been given to this most

important subject. The time, however, may not be far dis-

tant when the same rigid inspection and the same jealous

care will be extended to one of the most important adjuncts

to the life, health and comfort of every individual, of every

society and of every commonwealth. >

PUBLIC WATER SUPPLY FOR SMALL-TOWNS.

M. A. VEEDER, M.D., Lyons, N. Y.

Drinking water that is manifestly bad does not make

everyone that uses it sick. Even when the mains and reser-

voirs of a public water-system have been infected by such a

poison as that of typhoid it is only exceptionally and for lim-

ited periods that as many as one per cent. of those using the

water contract the disease. An outbreak of 2,000 cases in

a population of 200,000 is ordinarily regarded as a severe

epidemic, and yet this is at the rate of only one person in a

hundred. It is this immunity on the part of the great mass

ofthe people that permits infected systems of water-supply to

continue in operation. If there were no resisting power on

the part of the individual, all would die on the slightest

exposure and the source of danger would soon be thoroughly

identified and avoided. As it is, however, for every one that

contracts the disease there may be as many asa hundred who

escape. Thus it becomes a question of probabilities, and

there is a chance for much plausible theorising and contro-

versy. Gradually, however, as the result of increasing obser-

vation and experience, crude ideas that have prevailed are

being eliminated and the truth of the matter established.

Only a few years ago the most essential point in the

improvement of water-supply was thought to be the determi-

nation of the chemical ingredients held in suspension or solu-

tion. Elaborate systems of analysis were devised for this

purpose, and the quality of the water was judged almost

entirely by itschemical reactions. Thus it became customary

to consider the questions involved from a chemical point of

view exclusively. The simple dilution of contained matters

of a chemical nature, if carried far enough, would make them

PUBLIC WATER-SUPPLY FOR SMALL TOWNS. WZ.

harmless. Consequently large bodies of water were supposed

to have a power of self-purification in direct proportion to their

size. In like manner precipitation, sedimentation, aeration and

other chemical and mechanical processes were supposed to have

a purifying effect. The quantity of sewage entering a stream

being known, it becomes possible to tell with a good degree

of certainty at what distance, mingled with such a volume of

water, it will become so diluted, diffused and changed as to

be unrecognisable by any chemical test. The dose of poi-

sonous matter, if of a chemical nature, ought to be divided

and subdivided to such an extent as to be entirely harmless

in the quantity of water that any individual would consume.

In practice, however, this is not found to be the fact, sewage

infection being capable of producing epidemic disease for

many miles along a stream entirely out of proportion to any

possible chemical process of diffusion.

The whole tendency of modern research has been to show

that the question as to the spread of disease through the

agency of water is biological rather than chemical. It is the

presence of certain living organisms and of the conditions on

which their continued existence depends that leads to the

spread of disease. A single seed may be the means of over-

spreading an entire continent with some form of luxuriant

growth, and so a single disease germ may start an epidemic,

not through any mechanical or chemical process of division

or subdivision, but because having life it grows and multi-

plies.

The danger consists not in the quantity of such organisms

but in their power of growth under given conditions. If

capable of living in water, they may infect an entire stream

instead of disappearing by processes of dilution within a few

rods. Unlike chemical poisons, they have no fixed poison-

ous dose. The smallest possible inoculation may prove fatal

through the power of self-propagation which they possess.

If, on the other hand, their growth be hindered by unfavor-

able temperature, moisture, or food supply, they may become

harmless no matter what their quantity. It is true that they

178 M. A. VEEDER:

have chemical effects, originating substances known as tox-

ines, some of which are deadly poisons, but they themselves

depend upon the possession of life for the modes of activity

which they exhibit. Throughout it isa question of vitality

under particular surroundings.

Typhoid fever, cholera and certain forms of dysentery are

the chief diseases whose infection it is generally admitted can

live in water. In addition, about ten years ago, the writer

came to the conclusion that the term malaria, signifying bad

air, is a misnomer, and that diseases of this class are very

largely, if not exclusively, conveyed in water. Towns taking

their public water-suppiy from ponds or streams having dis-

tinctly malarial surroundings have become subject to such

fevers although previously free from them.

The manner of spreading. of the diseases which have been

named originates two classes of dangers. If water be taken

from the vicinity of human habitations there is liability to

contamination from excreta washed into the pond or stream

used as a source of supply, or, in the case of wells, the strong

action of powerful pumps may originate a rapid flow under-

ground extending many hundreds of feet and carrying

impurities through coarse gravel or open crevices in the

soil. That this is the fact appears from the manner in

which ordinary wells at a considerable distance from the

pumping station run dry when the latter is in operation.

Such contamination from human sources may originate

typhoid and diarrheal disorders. If, on the other hand, the

source of supply is remote from human habitation there may

be malarial contamination. Indeed the natural habitat of

malaria is in new and undrained countries and virgin soil.

In view of this distribution of the disease it is surprising that

well-drained cities, having perfect sewers, should yield a cer-

tain percentage of malarial fevers until the source of their

water-supply is noted, it being in such cases, as a rule, some

pond or stream in whose vicinity these diseases are prevalent.

Shallow wells in alluvial soil also may yield malarial infection.

It is said that since the substitution of deeper artesian borings

PUBLIC WATER-SUPPLY FOR SMALL TOWNS. 179

for such wells there has been a notable decrease of malarial

diseases in some parts of the Southern States of North

America.

In many localities it is difficult, if not impossible, to secure

an adequate supply of water free from the forms of contami-

nation to which reference has been made. This necessitates

some system of purification.

It has been discovered recently that there is an antagonism

between disease germs and what are known as nitrifying

organisms, which produce nitrites and nitrates in the soil.

Advantage has been taken of this to institute an intermittent

process of filtration. Water containing the bacteria that it is

desired to destroy is allowed to run into a filter composed of

sand, containing an abundance of nitrifying organisms, and

instead of being drawn off immediately is allowed to stand

for a sufficient length of time to permit the destruction of the

disease germs by their natural foes.

Such filtration as that just described is but the perfecting

of natural processes. Alternation of rainfall and dry weather

operates substantially on the same plan, tending to purify the

ground water in the soil from infection and making wells pos-

sible. Thus in localities where artificial filter beds are

impracticable it may be possible to resort to wells with similar

results. Experimental borings are required in order to deter-

mine whether the quantity of water is adequate and whether

the soil through which it percolates is adapted to secure its

purification. This being done and the system established,

the intermittent action of the pumps, running a part of each

day, like intermittent filtration, yields a much purer supply

than could be had in any other way. A point to be guarded

against is the influx of surface water, which is specially liable

to contain malarial infection as well as other impurities. To

this end, numerous small wells, consisting of iron pipes put

down tothe proper depth and having perforations over a

space of six or eight feet from their lower extremities, covered

with fine wire gauze, may be employed. Another plan that

may serve is to have a single large well, twenty feet or more

180 M. A. VEEDER:

in diameter. A convenient method of construction of such a

well is by the use of a curb, built up in a hexagonal or octa-

gonal form, of plank laid flatwise and spiked one upon the

other in layers. If such a curb be made, slightly smaller

toward the top, it can be carried down successfully through

almost any sort of soil and stoned up.

It has been thought best to enter somewhat into such

details as have been indicated, because they illustrate the

principles involved in improvement of water supply, especial

reference having been had throughout to localities whose

resources are limited. The adaptation of laboratory results

to practical uses is the point specially sought to be accom-

plished in this brief summary. The sanitary engineer, the

practising physician and the skilled microscopist are upon

common ground in these studies.

At the present stage of progress it must be admitted,

however, that serious imperfections are unavoidable in the

best systems of water-supply available in many localities.

This being the case, household methods of purification

require to be taken into the account. That preferred by the

writer is as follows: The water is boiled and allowed to

stand in a covered stone jar until all sediment has deposited.

It is then transferred to ordinary air-tight glass fruit jars, a

lot of which, having convenient modes of fastening, are kept

for the purpose. When putinan ice chest or cool cellar such

water comes out beautifully clear, sparkling and palatable.

Such water has no unpleasant flavor unless kept too long, and

even this might be avoided by sterilising the jars and filling

them with the water while hot, which would require reheating

after the sediment is removed. Practically there is no neces-

sity for this extra trouble. Certainly all the waters treated

by the writer in this way have proved to be excellent, and

there can be no question as to their freedom from the infec-

tion of any of the diseases that have been named in the dis-

cussion. It may be noted also that substantially the same

principle is employed when water is used for quenching thirst

in the form of tea, coffee, soups and the like. It is the boil-

PUBLIC WATER-SUPPLY FOR SMALL TOWNS. 181

ing that makes such waters safe, the various ingredients

added serving to please an acquired taste for the most part.

Mankind is accustomed to take many precautions of this

sort without any clear ideas of the reasons. It is the pro-

vince of advancing civilisation to enable such precautions to

be taken intelligently, and consequently more perfectly, and

this is the aim of the present discussion in regard to water-

supply.

THE INCREASING POLLUTION OF OUR MUNICIPAL

WATER-SUPPLIES.

FRANK J. THORNBURY, M. D., Burrato, N. Y.

It seems hardly necessary here to go into a detailed

account of the necessity for a pure drinking water. The

same is also precluded by the length of the paper which I

have prepared. Certainly no agent is more important to the

well-being of the human race—a fluid which constitutes about

three-fourths of the human body and animal tissues gen-

erally ; the universal solvent; the beverage of beverages,

essential to the performance of all the vital functions. As

vegetation on the earth’s surface would be impossible without

moisture, so also would the human body soon cease in its

vital phenomena without an adequate supply of hydrogen

and oxygen associated in their proper proportions. While it

is essential for the performance of these offices it is equally

necessary in removing the results of functional activity—

namely, waste tissue products. This brings us to the con-

sideration of purtty. As water can hold in solution only a

certain amount of solids, its solvent power in the system—

one of its chief effects—is necessarily impaired when it is

charged with compounds, organic and inorganic, and the

waste products which it should take up and carry off through

the emunctories, accumulate and exert their deleterious

effects, both mechanical and chemical.

While the system may combat for a time a certain excess

of mineral impurities, they sooner or later make their effects

manifest upon the excretory organs, the kidneys especially.

Just how much of a réle the lime salts carried by water have

POLLUTION OF OUR MUNICIPAL WATER-SUPPLIES. 183

in the causation of the pipe-stem arteries of advancing life,

in calcification and atheroma, is not fully established, but the

inference seems justifiable that such influence is considerable.

These changes conform to the pathological histology of con-

tracted and granular kidney the etiology of which is as yet

obscure, to the general condition of the circulatory system

known as arterio-capillary fibrosis. It being through the cir-

culatory system that water is carried through the body, and

constituting, as it does, about nine-tenths of the weight of

the blood and fluids therein contained, naturally it is in

the arterial and capillary systems that the effects of impuri-

ties thus carried are apt to be first noticed. Probably the

chief primary effect is simple irritation, as this would explain

best the microscopical changes characterising arterio-capil-

lary fibrosis.

So much with reference to the general circulatory effect

of the zzorganic impurities upon the system. The chief

feature of impure water which I wish to discuss, pertains to

its organic constituents, not chemical alone but biological ; to

the living pathogenic microorganisms which it is liable to

contain. I do not wish to enter into the effects of albuminoid

ammonia and other chemical products indicating serious pol-

lution of a water-supply, but rather prefer at this time to

confine myself to the subject of the bacterial contamination,

introducing, however, a few general considerations.

Undoubtedly the contamination of our municipal water-

supplies is at the present time reaching a degree which should

occasion great alarm, and no one who has given the subject

thought can fail to be impressed with the importance of a con-

sideration of the ways and means of suppressing the evil. It

is equally true that more ailments and diseases arise from the

use of impure water than from any other known cause, and

yet most people are conspicuously careless as to the quality

of water which they drink. In many cases this is the result

of ignorance ; in others it is due to carelessness.

Thus the subject becomes the most important sanitary

topic which we have to consider today, and thus far it has not

184 FRANK J. THORNBURY:

received the amount of attention which it merits. The con-

dition referred to is the natural outcome of the rapidly increas-

ing population of our country, without corresponding increase

of precaution in the disposition of sewage, which in most

instances is allowed to mingle with adjacent waters unaltered.

‘Even a small amount of sewage entering near the intake to

a water-supply is sufficient to destroy the small margin of

safety otherwise existing in regard to the water’s purity,”

(Rafter) and hence, as may readily be understood, there are

as yet few sanitarily unobjectionable water-supplies in the

United States. In many cities the condition of affairs is

really alarming, as attested by frequent outbreaks of typhoid

fever, or, as is the case in other instances, by the endemic

presence of this disease. Among such cities may be men-

tioned New York, Chicago, Philadelphia, Cincinnati, Pitts-

burg, St. Louis, Buffalo, Cleveland, New Orleans, Minneapo-

lis, Milwaukee and Detroit, besides many smaller towns. In

all of these and other parts we have frequent controversies

concerning the impurity of the local water-supply, and dis-

cussions and agitations as to the most available means of

improving the condition. In some of the cities active steps

have been taken, or are being taken, to abolish or mitigate

impending dangers. In others, too much politics and want

of proper sense of duty on the part of the authorities lead to

a continuance of the deplorable state of affairs.

To give an impression of the kind of water furnished to

the inhabitants in some of our large cities the following quota-

tion may be of service:

‘A sad state of affairs exists in Brooklyn. The source of

the water-supply is inadequate and the daily papers are full

of complaint. A lay contemporary, who has taken pains to

investigate the matter, speaks as follows: ‘From stagnant

ponds, vile and reeking, filled with dirt and decaying and

fermenting vegetation, covered with slimy decomposing

masses, swarming with bugs, insects and fish, full of white

snaky threads, receiving gas-house refuse and house drain-

age, and covered with green scum, ‘we get the water we

POLLUTION OF OUR MUNICIPAL WATER-SUPPLIES. 185

drink.’ No wonder the citizens howl, for this is a shameful

description of the water resources of a city that is soon to

wed New York.”

Naturally, sewage constitutes the most important source

of pollution of our municipal water-supplies. Could some

means of its treatment on a large scale (other than the sewage

farm system), as, for example, electrolysis, be devised, much

would be done toward solution of that much vexed question,

the purification of our municipal waters. As in preventative

medicine, prophylanis is the first law of sanitary science today.

Chicago discharges about 50,000 cubic feet of sewage per

minute into Lake Michigan, through its river, the Chicago.

London, England, has 200,000,000 gallons of sewage per

day. ‘‘Erie, Pa., has 5,000,000 gallons daily, and Toledo,

O., 8,000,000. Cleveland, O., in 1893, besides her sewage,

emptied 15,693 cubic yards of night soil into Lake Erie and

7,800 tons of garbage. Dunkirk has thirteen miles of sewer-

age.” (Krauss. )

From these figures an impression may be formed as to the

amount of sewage and refuse which any town has to dispose

of, and we may more fully realise the enormity of this influ-

ence in contaminating a body of water naturally pure. This,

to reiterate, is one of the worst penalties of increasing popu-

lation and the aggregation of the masses.

A timely contribution on the subject of sewage was that

of Mr. E. O. Jordan, of the Massachusetts State Board of

Health, (1889—90). Mr. Jordan reports on and carefully

describes twelve species of bacilli, most of them previously

unknown, isolated at the experimental sewage station of

Lawrence, Mass., and further adds an important report on

nitrification and the organisms concerned in the process.

The results of Mr. Jordan’s examination of the sewage of

Lawrence, Mass., gave an average of 708,000 living bacteria

per cubic centimeter, his highest result being 3,963,000 per

cubic centimeter. He obtained far greater numbers during

the summer months than at other times. Laws and Andrewes,

from whose report I take the liberty to quote, giving them due

186 FRANK J. THORNBURY:

credit, found that the number of bacteria in London sewage is

considerably higher than the above. Determinations of the

number of microorganisms in the sewage of the King’s

Scholar’s Pond sewer, London, in November and December,

1891, showed 2,618,000 and 3,179,000 respectively. In

their report to the London County Council the last-named

observers state that ‘‘in perfectly fresh sewage from St.

Bartholomew’s hospital on January 26, 1894, at 10.30 A. M.,

from which cultivations were made immediately, without

allowing any time for the multiplication of the microorgan-

isms, we found on an average 2,781,650 bacteria per cubic

centimeter. Two agar-agar plates, inoculated each with I

cubic centimeter of the sewage diluted 10,000 times and

incubated at 22° C., yielded respectively 216 and 330 colon-

ies.” Six similar plates, inoculated each with 1 cubic cen-

timeter of the sewage diluted 100,000 times, yielded respect-

ively 21, 39, 26, 27, 28 and 29 colonies. The same sewage,

however, after being kept for three days in a stoppered

bottle, showed an enormous increase in bacteria; a similar

plate, inoculated with 1 cubic centimeter of the sewage

diluted 100,000 times, yielded 388 colonies, representing

33,800,000 bacteria per cubic centimeter.

From the Fleet sewer on Snow-hill, London, the results

were somewhat higher. The sewage was taken on March 2,

1894, at 11.30 A. M., and cultivations were made immediately.

Three agar-agar plates gave 40, 28 and 34 colonies, yielding

an average of 3,400,000 bacteria per cubic centimeter. With

this sewage also further experiments were made to ascertain

what proportion of the bacteria present would grow at a

temperature of 37° C., or with the addition of .05 per cent.

carbolic acid, or under the influence of both these conditions

combined. Two agar-agar plates, inoculated each with a

cubic centimeter of the sewage diluted 10,000 times, with

the addition of .05 per cent. carbolic acid, and incubated at

37° C., yielded respectively 59 and 38 colonies, giving an

average of 485,000 organisms which could grow under these

unfavorable conditions.

POLLUTION OF OUR MUNICIPAL WATER-SUPPLIES. 187

“These results indicate that. a,temperatureiof (37°) C.

inhibited the growth of 73.4 per cent. of the total number of

organisms present in this sewage, while the addition of .05

per cent. carbolic acid inhibited the growth of 44.2 per cent.

of the total number; the combination of .05 per cent. car-

bolic acid, with a temperature of 37° C., inhibited the growth

of no less than 85.8 per cent. of the bacteria present.

‘‘Two agar-agar plates, containing each I cubic centi-

meter of the sewage diluted 100,000 times, but with the

addition of .05 per cent. carbolic acid, yielded, when incu-

bated at 22°, 11 and 8 colonies respectively, equal to

950,000 organisms per cubic centimeter of sewage able to

grow in the presence of this amount of carbolic acid, z. ¢., 50

per cent. were inhibited in their growth.

‘‘ With regard to the total number, of organisms present

in sewage, the highest results were obtained from a sample

taken at the Crossness outfall, London, England, at 2.30

P. M., of July 10, 1894. Six agar-agar plates were made,

each containing I cubic centimeter of the sewage diluted

100,000 times, and they were incubated at 22°C. They

yielded respectively 124, 127, 105, 119, 110 and 88 colonies,

or an average of 11,216,666 microorganisms per cubic ‘centi-

meter of sewage.” (Laws and Andrewes. )

Can one conceive how even great dilution of such sewage

in water can render it free from danger ?

‘« The sewage collected from the fever hospital at Homer-

ton, London, on May 23d, at II A. M., was examined chiefly

for the purpose of discovering the typhoid fever bacillus.

‘*No less than forty-five colonies resembled, at first sight,

B. coli communis, but of these less than a dozen responded

to the chemical tests (coagulation of milk, formation of gas

bubbles in gelatine shake-cultures, and production of indol

in broth,) which are relied on to distinguish the bacillus from

its allies. It was, nevertheless, if we except a certain strep-

tococcus found, the commonest, and certainly the most con-

spicuous, of the organisms present in this sewage. Those of

the forty-five colonies which failed to give some or all of the

188 BRANK ae THORNBURY =

three chemical tests must be classed, from their morphologi-

cal and cultural resemblances, as close allies of B. colz com-

munis, a near relative of typhoid, but we are unable to refer

them to any described species.

Proteus Zenkert, acommon putrefactive organism, occurred

twice. A bacillus allied to B. pyocyaneus, of green pus,

which we describe as Bacillus cloace fluorescens, occurred

twice.

The following other organisms were found to be present

in sewage in numbers varying from 200,000 to 2,500,000 per

cubic centimeter: Saczllus fluorescens stercoralis, Bacillus

albus puttdus, Bacillus fluorescens liquefactens, Bactllus cloace

fluorescens, Bacillus mycotdes, Proteus cloacinus, Proteus

Zenkert, a streptococcus coagulating milk, Staphylococcus

pyogenes citreus, Sarciya flava and its allies, and Dzplococcus

albicans tardissimus. Other bacilli which rapidly liquefy

gelatine and produce a green fluorescence, were found in

numbers varying from 10,000 to 200,000 per cubic centi-

meter.”

The method employed by Laws and Andrewes in their

study of sewage, which was designed to secure an equable

admixture of the material with the large amount of diluent

required, was as follows: Ten cubic centimeters of the mixed

and shaken sewage were diluted to 100 cubic centimeters

with recently boiled distilled water in a sterilised and accur-

ately stoppered flask, and thoroughly shaken. Of this dilution

IO cubic centimeters were taken and further diluted to 1,000

cubic centimeters with sterilised distilled water in a second

sterile flask, and again well shaken. Of this second dilution

(which represents I in 1,000) two further dilutions were made

in similar manner—one by taking 10 cubic centimeters and

diluting to 100 cubic centimeters (giving a dilution of I in

10,000), and another by taking 10 cubic centimeters and

diluting to 1,000 ubic centimeters, giving a dilution to I in

100,000. These extreme degrees of dilution were, of course,

rendered necessary by the enormous number of microorgan-

isms present even in fresh sewage. And even with the

POLLUTION OF OUR MUNICIPAL WATER-SUPPLIES. 189

extreme dilutions, the gelatine plates used for cultivating the

organisms soon became useless, on account of the rapid lique-

faction produced by the growth of bacterial colonies.

The disinfection of typhoid excreta is a matter of extreme

difficulty, and is, as a rule, very imperfectly carried out even

in fever hospitals. It hence results that sewage becomes a

very potent agent in the dissemination of this disease and the

contamination of water supplied by such sewage the chief cause

of typhoid epidemics. Attention to the inquiry which the

London investigators carried out was especially directed to

the possible occurrence of the Bacillus typhosus in London

sewage, and every colony which seemed likely to belong to

this species was the subject of careful investigation.

It is estimated that even though the typhoid fever bacillus

be intimately mixed with the city’s sewage from typhoid fever

cases direct, there will be only one typhoid fever bacillus in

one-tenth of a cubic centimeter of the sewage at the outfall.

So numerous were the failures of the above observers in their

attempt to find the typhoid bacillus in London sewage they

finally became oppressed by a sense of mathematical improba-

bility. The average amount of sewage produced in London,

England, is 200,000,000 gallons per day. Calculating that

200 cases of typhoid fever prevailed during the time when

the observations were made, it is estimated that the amount

of typhoid sewage amounted to one two-hundred-and-fifty-

thousandths of the whole. The investigators only found it

possible to work on one five-thousandth of a cubic centi-

meter of sewage

The chief interest which attaches to the contamination

of drinking water by sewage pertains to the possible

presence of the typhoid fever bacillus (or virulent colon

bacilli, which produce a train of clinical symptoms closely

corresponding with those caused by the former organism).

Laws and Andrewes have shown that in the drains froma

hospital where typhoid fever is prevalent the typhoid fever

bacillus may be isolated without difficulty. This had never

previously been done. The organism was, furthermore,

190 FRANK J. THORNBURY:

found to live in raw sewage, at the ordinary temperature, for

two weeks. Ata warmer temperature, even after thirty days

and in presence of pure cultures of various other organisms,

the typhoid bacillus was found alive and active. The

colon bacillus was cultivated in sewage through several

generations.

From the foregoing deductions it would appear that the

fact of the typhoid fever bacillus not being found more often

in water supplies is no particular argument against its presence.

The better method for demonstrating the presence of the

typhoid bacillus in water is by the inoculation of white rats with

samples of water placed in beef tea and incubated for twenty-

four hours at 40°C. The presence also of a small amount of

carbolic acid with the higher temperature will restrict the

development of most of the water bacteria, when we will

have remaining simply typhoid (or colon bacilli). Such cul-

tures injected into the abdominal cavity of a white rat

promptly lead to the development of severe inflammatory

symptoms or even death. Without this animal experiment

the task of finding the typhoid bacillus in drinking water is

often exceedingly difficult; with it it becomes compara-

tively easy. The new serum test, with which I am myself

now experimenting, promises to be an important aid.

[This consists in adding to a hanging drop of a mobile

organism a drop of blood (even after it has been dried) from

a patient suffering from typhoid fever, any time after the first

week. If the organism under consideration be typhoid its

motion ceases, the cells becoming agglutinated, when they are

seen in clumps or masses in the field of the microscope. If the

organism is not typhoid the motion continues. The writer has

tried the test upon a number of mobile organisms with the

result of convincing himself that the antitoxin of typhoid

fever does not act upon other mobile bacteria in the way

that it does upon the germ to which it owes its origin. |

Wide variations exist in the total number of microorgan-

isms present in sewage at different times and in different

places, as might be predicted. Temperature is one of the

POLLUTION OF OUR MUNICIPAL WATER-SUPPLIES. “191

most important factors in determining the rapidity of their

reproduction and increase in numbers. Dilution of sewage

by rainfalls exerts a marked modifying influence.

A striking difference exists between the organisms found

in sewage air and in sewage itself. The molds which pre-

dominate in the former are very rarely observed in the latter.

Out of the many thousand colonies which arose on numer-

ous plates made from London sewage mold fungi occurred

only seven times, and of these seven only one was allied to

the common species existing in sewage air. These results

coincide with those obtained by Jordan and others.

In showing the influence of locality on the number of bac-

teria present in different parts of a river the following obser-

vations are of value: The water of the Seine at Choisy,

before reaching Paris, is found to contain 300 bacteria; at

Bercy, 1,200; at St. Denis, after receiving sewer water from

the city, 200,000 germs per cubic centimeter (Miquel).

Water of the Spree beyond Kopenick, 82,000 bacteria.

Two hundred steps below the mouth of the Panke, 940,000 ;

below the mouth of the Panke, 1,800,000 (Koch). Water

of the Main river above the city of Wirtzburg, in the month

of February, 520; below the city, 15,500 (Rosenburg).

The water of the Thames in the autumn of 1885, in the

vicinity of London bridge, two hours after high water, con-

tained 45,000 germs per cubic centimeter; the water of the

Lea at Lea bridge, 4,200,000 (Bischoff). The water of the

Oder, collected within the limits of the city of Stettin, was

found by Link to contain from 5,240 to 15,000 bacteria per

cubic centimeter ; that of the Limmat, at Zurich, 346 in one

specimen and 508 in another (Cramer). The water of the

Spree river of Berlin contains 400 bacteria at the Stralauer

works.

Adametz (1888) has described 87 species of bacteria

obtained by him from water in the vicinity of Vienna;

Maschek found 55 different species in the drinking water

used at Leitmeritz ; and Tils (1890) has described 59 species

obtained from the city water used at Freiburg.

192 FRANK J. THORNBURY :

The following are the ordinary pathogenic organisms found

in water:

Pathogenic Bactllt.—Bactllus typhi abdominalis (Eberth,

Gaffky), Baczllus erystpelatos suts (‘‘ Bactllus murtsepticus,”

Koch), Bacillus septicemte hemorrhagice (‘‘ Bactllus cunt-

culicida,” Koch), Proteus vulgaris (Hauser), Proteus mirabilis

(Hauser), Bacillus canalis capsulatus (Mori), Bactllus canalts

parvus (Mori), Spirtllum cholere Astatice (Comma bacillus,

Koch), and a group of spirilla closely resembling it ; Baczllus

venenosus (Vaughan), Bacillus coli communis (Escherich),

Bacillus hydrophilus fuscus (Sanarelli), Lactllus venenosus

brevis (Vaughan), Baczllus venenosus invisibilis (Vaughan),

Bacillus venenosus liquefaciens (Vaughan).

Pathogenic Micrococct.—Staphylococcus pyogenes aureus

(Rosenbach), Micrococcus of Heydenreich—‘‘ Micrococcus

Biskra.” The former of the two last named germs being

the common producer of abscesses, inflammations and phleg-

mons.

Concerning the probable presence of the Plasmodium

malaria in drinking water that is charged with vegetable

matter from low marshy districts, we have an important sug-

gestion from the lower Mississippi Valley. So extensively

did this disease prevail in the large tract—the delta—between

the Mississippi and Yazoo rivers, population of the region

seemed for a time to be impossible. Now the use of artesian

wells there has brought a wonderful change. The residents

of the delta used to drink the water from small surface

streams, shallow wells and sluggish bayous. Asa result of

the use of water free from such surface contamination the

region has been robbed of many of its terrors and has proved

to be exceedingly healthy. For hundreds of years the Roman

Campagna was the home of the deadly fever called Roman

fever. The water-supply of the ‘‘Eternal City” was very

poor and the fever made great ravages; but since improve-

ment in the water-supply the death-rate of Rome is lower

than that of Naples, Florence, Turin and Milan, and there

occurs scarcely a death in Rome from malarial disease con-

POLLUTION OF OUR MUNICIPAL WATER-SUPPLIES.

tracted within the city.

193

While we in the North do not have

the extensive swamps of the Mississippi region, still there is

in the above an important lesson for us.

The following table may here be of interest:

ipts | Av aily | Revenue

Name of City. paral Wate Bom Coen Bee Mill- ee

; Water. in Gallons. | ion Gals.| 1rooo Gals.

New York. . | $3,457,347.04 | $1,520,897.20 | 154,000,000 | $ 61.50 .131%

eWicavoue we |e021502, 101.07 795,292.67 | 174,000,000 40.81 | .0o8—.1o

Philadelphia .| 2,634,481.52 125,705.73 | 163,800,000 44.06 08

Brooklyn.. .| 1,486,003.38 295,087.57 | 58,054,000 70.12 | .lo-.15

Stvouise= =|) 1,235,933. 30 555,850.50 | 44,162,000 76.67 | .1o-.30

Boston.. . 1, 838,494.30 587,850.50 | 46,740,000] 107.76 | .16-.1824

Baltimore . . 869,777.07 159,459.86 | 47,000,000 50.70 .06

Cincinnati. . 988,053.90 188,034.05 | 42,119,000 64.27 | .09-.15

Cleveland. . 598,433.50 253.3859) 36,443,000 44.98 .05%

Thus it will be seen that the subject of the water-supply

in every large city is one that involves great financial consid-

erations, and it would appear consistent to expend a little

more (or, in some instances, perhaps less,) and improve the

guality of the supply.

As I have discussed at length the subject of the purifica-

tion of water for drinking purposes, in the January, 1897,

number of The Chautauguan, I will not touch further upon it

here.

ON THE APPARENT STRUCTURE OF THE SCALES OF SEIRA

BUSKII IN RELATION TO THE SCALES OF

LEPIDOCYRTUS CURVICOLLIS.

R. L. MADDOX, M. D.,* Hon. F. R. M. S., SouTHamprTon, ENGLAND.

The structure of the scale of Lepizdocyrtus curvicollis has

occupied the attention of microscopists from the time it was

adopted by opticians in England, and I believe also in Amer-

ica, as a test object whereby to ascertain the correction of

their objectives, and yet the question may be asked, though

so often examined, has its structure been satisfactorily estab-

lished or accepted? Would not the general answer be a

negative one? It is feared it would. Now, I am not bold

enough to do more than to put in a plea for the careful exami-

nation of the scale of Sezra duskiz, which is more robust, in

the hope it may help in the elucidation of the finer marked

scale of Curvicollts.

It may be remarked that both scales are derived from the

Poduridz, and as they both present the markings termed

‘‘notes of exclamation,” may we not reasonably consider

that both are constructed upon the same plan, differing only

in minuteness of detail? I have been led to this subject by

finding some appearances in the scales of Buskzz, which

seemed to me to offer a chance of getting a little insight into

the real structure of both scales; but I at once readily con-

fess still to a difficulty in formulating a theory or statement

not open to question. It is, therefore, under this difficulty

the subject is approached and the following remarks offered

for the consideration of the members of your society. There

is, however, one point on which I have less hesitation, viz.,

* Elected an-honorary member of the American Microscopical £ociety, August 20, 1896.

THE SCALES OF SEIRA BUSKII. 195

that the appearances the scale of Sezra have presented, pre-

vent participating in the supposition that the notes in either

are due to minute spinous projections on either the upper

or under surface of the scale, or that they are anything more

than optically due to refraction through adherent and sepa-

rated portions of the membranes forming the surfaces and

the inner framework of the scale, surrounded by a more highly

refracting substance.

As the appearances in Curvicollis are so well known, let

me turn at once to the scales of Auskzz, where the notes are

so much larger. On taking a general view of these scales,

we find they differ very much in size and in the robustness of

the notes on the scale. The small scales often have the notes

stronger and thicker, or wider than in the large scales, and in

some the center ones run without a break from the stem to

nearly the point. This is shown in the Photograph No. I

x 710 diameters ; moreover, these small scales often scarcely

show any light areas in the note of exclamation, consequently

it seems to present a more or less solid structure. While the

larger scales have these notes many times more numerous

than the smaller scales, and almost all of them under high

powers show long open or light central areas, as in Photo-

graph No. 2, x 930 diameters. Looking on these as types

of the perfect scale, we meet with others which show that

there is between these notes throughout the scale a more

highly refracting substance, which does not in Busk7z7 appear

to be of such a fatty nature as in Curvicollis. This sub-

stance in many of the scales on the slide, which is an old one,

has receded in continuity from the stem toward the point,

appearing abruptly broken across in the interspaces between

the notes, yet at the same time leaving the lower point or

tail of the note a mere line ridge, or bar starting from the

base or stem end of the scale. This is seen in Photograph

No. 3, X 710 diameters. A step further, and this material

is found in a granular condition, occupying the interspaces

between the lower notes while the notes remain nearly per-

fect toward the point of the scale. See Photograph No. 4,

196 R. L. MADDOX:

x 1000, and Photograph No. 3, x 710, where the process is

fainter. One step more, and now this substance is seen dis-

persed throughout the scale in one uniform mass, save at

minute points on the edges, and only darkish lines, bars or

spaces are seen more or less extending from the stem to the

point. Here we may say we have entire obliteration of the

notes. Whathas becomeofthe notes? They have vanished,

leaving only shaded areas in their place. This appearance is

shown in Photograph No. 5, x 1000 diameters. It was then

finding these scales that led me to hope some clue could be

gathered as to the cause of the notes of exclamation, and

induced me to puzzle over what might be the entire structure

of the scale. For comparison I had by me the large engraved

plate of the scale of Lepzsma sacharina with copious marginal

notes, given me November, 1863, by the distinguished micro-

scopist and draughtsman, the late Richard Beck. Mr. Beck

found in his scale two sets of bars or lines which intersecting

each other at different angles thus produced either vertical or

oblique notes ‘‘ by the refraction of light, when the structure

of the outer and inner surfaces of the scale cross each other

in different directions.” And he states ‘‘that when moisture

is on the outer-surface, the radiating or the oblique lines

become continuous, but when the moisture is on the inner

surface, then the longitudinal markings are continuous, and

when no fluid is present, both sets of markings are inter-

rupted.” According to this view, the obliteration of the

notes is the effect of moisture. Now, in thescales of Buskzz,

it seemed to me, the obliteration of the notes is due to the

refraction, breaking up or universal spreading of the inclosed

more highly refracting substance ; in other words, that it is

broken down and no longer lies only in the interspaces

between the notes. At the edges right and left of the

base of some of the scales, we have more or less indications

of the oblique lines found in Lefzsma, but I have failed

to trace them, and if they exist beyond or towards the stem or

the central part of the scale, I consider they do not from their

direction any way share in the cause of the long or longitudi-

THE SCALES OF SEIRA BUSKII. 197

nal notes in 4uskzz. How then can the appearance of these

notes be explained? May we not suppose that the struc-

ture of the entire scale consists of a very delicate oblong bag,

more or less conversely curved on its outer surface, and more

or less flat or concave on its inner surface, or in cross section

somewhat plano-convex or convexo-concave, and that these

delicate membranes are supported or strengthened by an

inner framework of longitudinal bars, extending from the

base and gradually approaching the center, until they nearly

or quite meet at the tip of the scale, all but the most central

ones taking a slight curve right and left at the base, and fol-

lowing the shape of the scale. The membranes of the bag I

regard as plain, though some may possess a few lines or bars

radiating from the stem each side, which I regard as due to

curved notes embracing the lower rounded or more inflated

edges of the scale. This small sac seems filled with a semi-

solid or thick fluid substance of a rather higher refracting

power than either the membrane or framework. In addition,

if we suppose that the two membranes, z. ¢., the upper and

under, adhere in part to the longitudinal bars of the sup-

porting inner frame in their course to the point of the scale,

and break away from the bars at various points to again

unite either to the same bar or its neighbor, repeating the

process of adherence or close approximation and separation all

over the scale, should we not have the bright areas ; and if

the bars were themselves at all concave and the membranes

touched the edges, but not the center for the whole length of

the note, should we not have the appearance of the open

areas, the head of the note being closed in by the capillarity

of the semi-fluid interspace substance ? This would tend to

give the bars a more or less double outline, as in the Photo-

graph No. 6, x 930 diameters. This may appear as only a

fanciful rendering of the structure, but had I to try and fabri-

cate a monster scale with any transparent plastic substance,

it would be the first method adopted. The point or dark

tail of the note would have the bar and membranes closely

adherent, the clear areas the membranes only adherent

198 R. L. MADDOX:

to the edges of the bar, and then interrupted to repeat this

arrangement. It may be noted that where the scale com-

mences to have the notes changed into the appearance of

only longitudinal lines or bars, the change always begins, as

far as I can find, at the stem end of the scale, though the

breaking up of the inner substance into a granular state may

be only scantily apparent, and this change is regarded as

sufficient to disturb the adherence of the membranes along

the bars, working the same change gradually toward the

apex, as seen in Photograph No. 4, x 1000 diameters. If

complete, then the appearance shown in Photograph No. 5,

at the same magnification, though the framework is only

faintly indicated, possibly due to the inner substance having

lost its original character and refractive quality. It may be

said there is no true framework, and the bars are formed by

folds or creases in the upper or under membranes ; but in my

examination and dissection, years since, extending over a

long period, I was able to find an inner framework in the

butterfly scale, and this tempts me to the idea of an inner

support in the scale of Buskzz.

To repeat, the dark line in the tail of the note is sug-

gested as caused by the close adherence there of the three

parts, upper and under membrane with that part of the frame

and as it exists for a variable distance, so the tail of the note

may be of variable lengths. The open or central light area

is regarded as one of the two membranes adhering only at

the edges, right and left of that bar, the interspaced material

being drawn by capillarity close to the edges, thus assisting

in forming the somewhat sharp ovtline at that part, and this

process to continue through the length of the bar to the

point of the scale, or to occur in the neighboring bars irregu-

larly in Buskiz, but more regularly in Curvicollis, where the

interspace material is more or less fluid, and of a more refrac-

tive nature. The photograph of the Podura scale Curvicollzs,

is given just to show that in certain positions in relation to the

illuminating rays, the indication of lines becomes apparent,

and these are often lost in injury to the scale by reason of its

THE SCALES OF SEIRA BUSKII. 199

delicacy and the highly refracting quality of the interspace

material.

It must be distinctly understood that the above remarks

are not put forward in any dogmatic spirit, but in the hope

that in directing attention to the scale of Auskzz, clearer

views may be formulated, both of its structure and that of

Curvicoliis. At any rate it is trusted that the subject may

prove of some interest to the members of your Society, and

the readers of your TRANSACTIONS which abounds in inter-

esting details connected with microscopy.

200 THE SCALES OF SEIRA BUSKII-

No. I. A small perfect scale, x 710 diameters.

No. 2. The same large scale as No. 7, showing the notes, X 930 diameters.

No. 3. A medium scale, showing the bars at the base, the interspace

material receding and granulation begun, X 710 diameters.

No. 4. A medium scale, with the granulation further advanced towards

the apex, X I000 diameters.

No 5. A medium scale, with the change completed and the notes lost,

leaving only faint indications of previous existence, X 1000 diameters.

No. 6. The same large scale as Nos. 2 and 7, focused into showing a

double line appearance, X 930 diameters.

No. 7. A large perfect scale, X 668 diameters.

No. 8. A CurvicoliZs scale, showing a sort of lined appearance, especially

on the right hand, and by way of comparison.

THE RED BLOOD CORPUSCLE IN LEGAL MEDICINE.

MOSES C. WHITE, M.D., NEw Haven, Conn.

Much has been written on this subject, and Clark Bell,

Esq., in an able symposium, has shown that the consensus of

scientific opinion may be summarised in the following declara-

tion, viz., that ‘‘by careful and competent observers, with

instruments of high power, a reliable discrimination can be

made between human blood and the blood of other mammals,

when the size of the red corpuscle is much smaller than those

of man, notably in the case of the ox, the horse, the goat,

the sheep, the pig and most other mammals.”

In contravention of this opinion, Professor Marshall D.

Ewell, M. D., in his address delivered at Rochester, N. Y.,

in August, 1892,* advances the opinion that ‘‘the very

utmost the present state of science enables us to state is that

the blood in question is or is not that of a mammal, a bird,

fish or reptile. To say more than this is, in my judgment,

without warrant to imperil human life, and, in the words of

the late Dr. Woodward, to make scientific experts more dan-

gerous to society than the very criminals they are called upon

to convict.”

As this startling proposition has never been answered in

the TRANSACTIONS of the American Microscopical Society, I

offer the following discussion of the subject, which I had the

honor to read before the Medico-Legal Society in December,

1894. Professor Ewell’s arguments, which I controvert, will

be found in the TRANSACTIONS of this society and in the

Medico-Legal Journal, Vol. X., No. 2, September, 1892.

Professor Ewell ruled a series of eleven lines on glass,

giving ten spaces of approximately 0.004 inch, and another

* TRANSACTIONS American Microscopical Society, Vol. XIV.

202 MOSES CC. WHITE:

set with five spaces about 0.008 inch, and gave these plates to

several microscopists to report from careful measurements the

values of the ruled spaces. According to Professor Ewell,

in the results of the measurements made by the six micro-

scopists, there were differences in the results of their meas-

urements greater than ,,, of an inch, which Professor Eweil

saysds greater than the greatest difference between the differ-

ent measurements of the blood corpuscles of man and some

common domestic animals, z. e., dogs. Although these meas-

urements were made with low powers, I in., 3 in., § in., 7%

in., } in., and 4$in. objectives, giving magnifying powers

approximately of 100 to 500 diameters. Professor Ewell

appears to think such powers might give as accurate measure-

ments as higher powers. He says:

To the objection that a low power was used in every instance, it may be

answered that where the power is high enough to make the object clearly visi-

ble and of an appreciable size, as was the case in these measurements, and

where a series of measurements are made, the result is practically the same as

if a higher power were used.

The consequences of this startling proposition are too great

to allow it to be passed over without careful criticism.

Gulliver’s measurements of blood corpuscles were made

with a magnifying power of 600 diameters. Woodward,

Richardson, Treadwell, Wormley, Piper, Formad and most

microscopists who figure in Medico-Legal cases at the present

day, have used powers ranging from I,000 to 2,500 or 3,000

diameters. Professor Ewell, himself, favors 1,000 diameters

for use in measuring blood corpuscles, and yet he puts forth the

discrepancies between measurements of different observers

with powers of 100 to 250 diameters to discredit the distinc-

tions observed with powers of 1,000 diameters, or even 3,000

diameters between the blood corpuscles of man and the

domestic animals.

As a further answer to Professor Ewell we may cite obser-

vations recorded by Professor Wormley, in Micro-Chemistry

of Poisons, page 728, wherein a series of ten spaces ruled on

glass, measured by three observers with different instruments,

THE RED BLOOD CORPUSCLE IN LEGAL MEDICINE. 203

the results did not differ more than ,J,, of an inch. Also

two independent series of measurements with high powers,

of twenty designated blood corpuscles were absolutely

identical for sixteen corpuscles, and for the other four the

greatest difference was only ;4, of an inch. Still further,

Professor Wormley reports the measurement of seven human

blood corpuscles with powers varying from 1,150 to 3,500

diameters by different micrometers, and by drawing with

the camera lucida. The range of averages of the different

measurements was ;, of an inch, to 5, of an inch, as

measured by the camera lucida. The mean of the averages

being ;, of an inch. The same seven corpuscles measured

by Dr. Richardson, using a cobweb micrometer, gave a final

average of ,, of an inch, differing from the former aver-

age by something less than ,,, of an inch.

To further show the uniformity of results obtained by

different observers, I would mention that on a slide of human

blood irregularly spread and dried so that the corpuscles on

one-half of the slide appeared larger than on the other part,

Dr. T. measured, with high powers, seventy-five corpuscles

on the side showing the larger, and seventy-five on the side

showing the smaller corpuscles. The average of the 150

corpuscles thus measured was ,,- of an inch. The writer

using a power of 1,400 diameters and a cobweb micrometer

measured fifty corpuscles on one part of the same slide and

fifty on the opposite part of the slide, and found the average

of the 100 corpuscles to be jj of an inch, differing by only

am of an inch from the results obtained by Dr. T. on the

same slide.

With the above demonstrations of corresponding results

of measurements made by the microscope in the hands of

independent observers, using powers of 1,000 diameters and

upward, I think I may dismiss the objections of Professor

Ewell, based on slight differences obtained by different

observers with powers ranging from 100 to 400 diameters,

whether due to defects of instruments or to the personal

equation of the observers.

204 MOSES C. WHITE:

1. The woolly appearance and uncertain limit of the blood

corpuscle is claimed to interfere with accurate measurements.

In answer to this objection, I present photographs of the

human blood corpuscle magnified 630, 840, 2,560 and 10,850

diameters respectively ; which, I think, show about as sharp

edges as any objects can show with such enlargement.

Again, the fact that different observers working with dif-

ferent instruments can and have measured a series of corpuscles

with results differing less than ;4, of an inch, shows a mutual

agreement in regard to the exact limit of the border.

The chief cause of the indistinct outline of the edge of

the corpuscle may be accounted for by the excessive thinness

- of its edge, which is very translucent.

Another fact in regard to the limit of the edge of the cor-

puscle to be measured, arises from the fact that the corpuscle

of mammalian blood is a bi-concave disc, with a thick border,

thin at the center and falling off to a rounded edge, which,

acting like a section of a convex lens, produces the appear-

ance of a dark ring surrounding the corpuscle. Some

observers measure the whole of this dark ring, others measure

one-half the ring, and a few perhaps reject the dark border as

no part of the corpuscle.

The late Dr. Woodward of the U. S. army, measured

from the center of the dark border of the corpuscle on one

side to the center of the dark border on the other side because

(as he said in his testimony at the Hayden trial in New

Haven in 1879) he could bring the spider lines of the micro-

meter to the center of the border on each side with more

certainty, than he could bring them to the edges of the

corpuscle. Others have pursued substantially the same

course, so that in the reports of measurements of blood cor-

puscles published in the journals, and in works on legal medi-

cine, we know not how much of the corpuscle was really

measured by the different observers. Now, as the dark bor-

der of the corpuscle has a breadth of about one quarter of a

mikron, or ,,,, of an inch, this mode of measurement would

reduce the average diameter of the. human blood corpuscles

THE RED BLOOD CORPUSCLE IN LEGAL MEDICINE. 205

from ;, inch, to yg, of an inch, or if the dark border was

rejected altogether, the average diameter would be reduced

to ;,, of an inch, which is exactly the diameter given by Hans

Schmid in 1878. These facts show that in quoting the

standard measurements made by experts, we ought to be

informed how much of the corpuscle was measured, if we

would compare the work of one expert with the measure-

ments made by another.

I have satisfied myself that the whole of the dark border

on both sides of the corpuscle should be measured. I have

ground glass discs in the form of the human blood corpuscle,

and found that the border of the dics presented a dark ring like

that seen when the blood corpuscle is seen in the microscope.

I have also carefully measured the corpuscle seen by transmitted

light showing the dark border, and have also measured the

same corpuscle seen by reflected light, in which the border did

not appear dark but of a color like the rest of the corpuscle,

and I have found the measurement in the two cases the same.

Among the most valuable recent contributions to the

study of blood corpuscles, is the article of Prof. Marshall D.

Ewell in the Wedico-Legal Journal, Vol. X., No. 2, Septem-

ber, 1892, which I have referred to above.

After noting differences in the results of measurements of

spaces ruled on glass, which we have noted above, he shows

by measurements of 100 corpuscles of his own blood, taken

on six different days, that there were slight differences on the

different days, varying from 9.05 mikrons to 8.23 mikrons, the

general average being 8.03 mikrons, the greatest average

differences on different days being about ;, of aninch ; show-

ing that for the same individual while in health, the average

of 100 or more corpuscles remains substantially constant.

The following table of measurements of blood corpuscles

of man and domestic ‘animals, which I published in Wood’s

Handbook of Medical Sciences, is better adapted for the

purposes of this discussion than any other with which I am

acquainted. This table was reduced by the writer from

measurements made by the late J. B. Treadwell, M. D., of

206

MOSES 1G) WHEE:

Boston, with a z's inch objective, made by R. B. Tolles, and

a Jackson eye-piece micrometer made by Tolles, ruled by

Professor Rogers, and a stage micrometer, ruled, tested and

rated by Professor Rogers :

SOURCE OF BLOOD.

. 5 No. of | Mean

M Mik , = :

yaaa ieeaea eed aoe eae

Five men, ages 23 to 49 years. 1000]7.941 \

Bive women, ages 28 19 5511 cody ger}

Three infants at birth, I male,| {

MEMES 6 6 0 oO a be 6 | ge 7.950 }

Boy, 8 yearsold...... | 200 7.983 |

Man, 70 yearsold. ... . : 200 7.916 }

Fifteen persons, as above. . i 000 7.938}

Blood stains (human) restored 1 1000 7.910}

Woman, I9 years old, anemia i 100 7.346 }

Child, 6 weeks old, starved to ss

Geathye Gagesaeece : { LO0|7-573 \

Twenty-five dogs, een ‘100 i) Bele ist

corpuscles . ealne 5 9 f

Pigs, 2 of 3 months, I “of 2) § bealotes

WWECKSI ei oy Nelaeers ate a let an : \

Ox, 3 males, 2 eremaies I of! §

I day, I of 3 MORES jf exis Loans 436 |

Horse, Io years old. 200 5.503 }

Ass, I male, I female... . 400 6.293 \

Mule, 6 yearsold...... { 200|5.421 \

Two cats, I adult, I kitten 3} §

weeks old ene 5-463 \

Male cat, stupefied 5 hours §

bytalcohola4 sys tye ieee 5.489 }

Guinea-pig, male, 3 months . 200 7-476 \

Two rabbits, I white, I mixed i 4006. 365

vatesrall Gmementera ete) Couette 200|6.500 t

Sheep, male, 15 days, female, | §

afeeh mip op oO diac fomeow a « c le merelty 745 \

Goat, I male, I female. . . | 400} 3.567

. |Av. by

10'S.

Av by

20's.

Av.by

50's.

Av.by

100’s.

Av. by

200'S.

7.697

8.152

7.825

8.152

7.667

8.298

TTAd

8 282

7.658

8.121

5-773

9 394

6.350

9.287

4 233

10. 160)

6.929

9.160

7.005

9.230

4 233|7.658

10.160/8.298

5 57°|7

9 687|8.189

3.464

9.237

4.405

8.636|7.712

4.618|6.138

8.931|7.352

3.849|5.418

8.391

3.916

6.774

4.618

6.774

5.003

7.697

3-464

6.312

2.617|4.311

6.774|5.780

4.772 5.327

7.605

5.703

5.203

6.566

5.680

7.235 5.080

5.849 7.231

8.390 8.698

4.618 6 196

8.082 6.596

3.079 6.289

8.005 6.820

3-079 4.503/4

6.774'4.972

2.617/3.394

ose e704

.700

6.674

7.328

6.520

55S

5.818

6.018

5.280

7.782

8.110

7.787

8,026

7 716

8.100

7.828

8.191

7.662

8.105

7.662

8.191

7.723

8.010

7.012

7.628

7 493

7.639

6.445

7-305

5-757

6 466

5.296

5.622

7.845

8 O61

7.873

7-993

7-833

8.031

7.891

8 079

7.768

8.028

7.768

8.079

7-177

7-515

7-572

7-574

6.523

7.258

5.880

6.246

5-345

5-543

5.257|5 473

5.633 5.553

6.1386, 201

6.539]6.377

5-327|5-377

5-545|5.472

4.361/5.268

5.676/5.573

5.426|5.479

5 846|5.498

7.309|7-249

7.659|7.634

6.227/6.294

6.845|6.409

6 346/6.441

6.695|6.694

588) 4.665

4.869) 4.785

3-401|3.467

3.710/3.693

7.884

8.046

7 gOl

7.963

7.918

7.983

7.965

8,000

7.852

7.980

7.852

8.046

7.346

7.573

6.673

7.198

5-347

5.482)5.

5-493

5-513

6.376

5.419

5.424

5.522

5.489

7-393

7-559

6.349

6.383

6.490

6.510

4.725

4.764

3-535

3.638

6.02816.

6, 169)6.

6.2196.

5-419|5.

7.903

7.983

7-913

7.950

7.938

7-970

7-983

7.916

7.903

7-983

6.354

6.377

4.744

4.746

3.546

3.587

* From an article on Blood Stains by M.C. White, M. D, in Wood's Handbook of

Medicine.

THE RED BLOOD CORPUSCLE IN LEGAL MEDICINE. 207

In this table the measurement of 3,000 corpuscles from

man are given, 200 having been taken from each of fifteen

different persons. The measurements are given, maximum

and minimum, by tens, by twenties, by fifties, by hundreds

and by two hundreds. Six hundred from pigs were meas-

ured; 200 from a pig three weeks old, 200 from one of two

months, and 200 from a pig three months old.

As the corpuscles of the pig have a larger average than

those of the ox, horse, sheep or goat, we make our compari-

sons between the blood of man and the blood of these three

young pigs.

Mikrons. Mikrons.

Man, smallest ten... .. . 7.658 Warees tate Niemen ite eee ee OEZ OS

Pig, = Sees to Paar Sea eS SSR rodeo Gi, ota np OLR ZO

Man, smallest twenty... . 7.662 Margeststwenty. 110s (i enOMLOL

Pig, as ot Sane er er hil < a Slee 6) Onarre aoe OATS)

Mac, smallest fifty. . ... . 7:768 Warsest filty peso) ea setueon ea KOLO O

Pig, os Ges rere mi Geeres) OY Lien iten ica, Gibbet hey dey OL AANS

Man, smallest hundred . . 7.852 Largest hundred... .. . . 8.046

Pig, ce eg Ao BGR Hs es Dials: Reo On OS

Smallest ten from man... . . . 7,658 mikrons.

Largest ten from the pig. . . . . . 6,520 as

Difference. . . . . 1,128 mikrons.

This equals 0.000045 of an inch,—ss,, inch.

Smallest twenty from man... . . 7.662 mikrons.

Largest twenty from the pig.. . . . 6,466 a

Difference. . . . . . 1,196 mikrons.

This equals 0.000047 of an inch,— ;,}4,, inch.

Smallest fifty from man . ... .. 7,768 mikrons.

Largest fifty from the pig... . . . 6,246 ei

Difference. . .. . . 1,522 mikrons.

This equals 0.000060 of an inch,—,,44, inch.

Smallest hundred from man. . . . 7,852 mikrons.

Largest hundred from the pig. . . . 6,169 a

Difference. - =... . 41,683 mikrons.

This equaJs 0.000066 of an inch,—;;+,; inch.

We thus see that where only ten corpuscles are measured

from man, taking the smallest average of ten consecutively

measured, this average for an adult man is one-sixth larger

than the largest average of ten consecutively measured from

208

MOSES C. WHITE:

a young pig only three weeks old; while the smallest aver-

age of one hundred from man taken consecutively is between

one-fifth and one-fourth larger than the largest one hundred

taken from the pig. :

TaBLE SHOWING DISTRIBUTION OF VARIOUS SIZES OF BLOOD-CORPUSCLES

MEASURED IN PARTS OF AN INCH.

Fractions of aninch)

Man.

hig.

Ox.

(By J. B. TrREapwELL, M. D.*)

No. of corpuscles. .

Maximurmicncne secre

Minimum

Mean

seen eens

ers

3-2727 |

I-3203

1-4400

1-3657 |

1-3473

I-5500

1-4227

200

1-3837

I-5500

Sheep. Goat.

2° Ai evele(e jeleatnjeliaiaaae

TS. ¥ Uijeasteto meee

S* | Osea spear

eos eisg goSA 0

19 cite

5h Ma ESS Ie 5.5.

20;> 8 |i cee

Fes Pe ee crchs o-

GON Nes A. ere

47 © 427 acldelne eee

bo OT Sc,

3. . dol soe eee

6 3

I re)

° 2

oO 4

= 5

I 30

o °

u 45

a eee veneers Oo

200 200

I-4647 1-5892

1-6600 1-8048

1-6204 1-6839

1-4654

* The number of corpuscles include all found between the fraction opposite to which

they are placed and the next succeeding fraction of an inch.

THE RED BLOOD CORPUSCLE IN LEGAL MEDICINE. 209

Professor Ewell says—Medico-Legal Journal, Vol. X., page

201—that ‘‘ fasting diminishes both the size and number of

the red blood corpuscles. This is also true of various drugs.”

This agrees with my case of achild six months old, starved to

death, given in the preceding table.

A stain from human blood in such a case might possibly be

mistaken for that of a dog or a pig. Such a condition might

tend to acquit a guilty person, but never to convict of murder

an innocent man.

Professor Ewell says: ‘‘ Many diseases alter the size of

the red blood corpuscles,” and he gives the result of careful

measurements which he has made in a number of diseases. I

take great pleasure in acknowledging the excellent work done

in this line by Professor Ewell, and, for the present discus-

sion, I have compiled from Professor Ewell’s reports the fol-

lowing table :

| No. of |Mean in ; B B

Source oF Boop. es Mikrons,| M@*- | Min. Ae 2 ro s

Repnsp Man es... . 7 2050 8.03 | 9.98 | 503 8.28 7.95

Boy, 36 hours old .. . ..!| 200 8.86 | 11.39 5-70 | 9.06 | 8.65

Adnlt Man... ... - || 400 7:85 || (Gr32 6.73

Purpura Hemorrhagica oe =|) 200 8.26 | 10.87 3.45 8 28 8.25

Two cases Pseudo Leuco- } |

cythemia . Seat e Sei Bas, G50) e 55 8.42

Tuberculosis Anemic. . | 100 | 8.35 | 10.70 5 35 |

Pinmbism ssc |. =. = | 100 8.65 | 10.10 5.18

‘CARISTI OD 4) deen Sena 100 8 32 | 10.18 6 22

Two cases Syphilis... . . 200 8.11 9.32 3.97 8.11 811

Erysipelas... . sop oo ol Ie 7.83 9.15 6.90

Pernicious Anemia . eee) te 100 7.69 9 93 6.04

Menstrual blood. .... . 100 Veal 8.80 5-76

2,350 8.14 | 11.39 3.45 9.06 7.95

If we take ,4, of an inch, or 7.937 mikrons as the gener-

ally accepted average diameter of human blood corpuscles,

and compare it with the average obtained by Professor Ewell

from blood in diseases, we find his largest avetace is in

plumbism or lead poisoning and is 8.65 mikrons, ; or a little

over one-twelfth part larger than the normal average.

Z2¥O MOSES) Ca WiHiGheE =

Now, if we take the young pig, which, excepting the dog,

is the domestic animal having the largest corpuscles, and to

the normal average of the pig, 6.10 mikrons, add #3 its diam-

eter, 0.55 mikrons, we shall obtain for the blood of a diseased

pig an average diameter of 6.65, which is smaller by 1.287

mikrons than the average human blood corpuscle.

This possible enlargement by disease is only one-third the

difference between the blood corpuscle of man and that of

the pig.

Certainly no microscopist of ordinary skill, provided with

modern instruments, rated to measure ;,,, of an inch, like

the ordinary filar micrometer, with powers of 1,000 or 1,500

diameter ; or even the glass eye-piece micrometer, rated to

ows OF EVEN = Of an inch, would be in any danger of mis-

taking blood of even a young pig (whose corpuscles had been

enlarged by disease as much as that of the man suffering by

lead poisoning) for human blood.”

Professor Ewell further objects that ‘‘drying the blood

corpuscles in a clot multiplies the difficulty of identification,”

and says: ‘‘It has never been proven that dry corpuscles

can be restored to their normal proportions,” and continuing

says: ‘‘In view of the foregoing it is impossible in the

present state of science to say of a given specimen of blood,

fresh or dry, more than that it is (or is not) the blood of a .

mammal.”—WMedico-Legal Journal, Vol. X., p. 201.

In answer to this objection, I again refer to the table of

measurements given above, whichI have quoted in part from

my article on Blood Stains in Wood’s Handbook, showing

measurements of 3,000 corpuscles of fresh human blood,

including males and females of all ages, from the infant at

birth to the man of seventy, contrasted with 1,000 corpuscles

restored from stains of human blood. The measurements are

in mikrons.

THE RED BLOOD CORPUSCLE IN LEGAL MEDICINE. 2I1I

Number of Individuals.

Number of

corpuscles.

Average

Fifteen persons, aa 3,000 | 7.938] 4 233) 7-658] 7.662| 7.768] 7.852] 7.913

- O.1 -9

Stated!. a... 10.160] 8.298] 8.191 | 8.079 | 8.046| 7.983

Blood stains — 1,000] 7.910] 5.570] 7.700] 7.723

IIVAM 4s) sss 9.687 | 8.184] 8.010

Three young ) €00} 6.101} 3.849] 5 418] 5.757] 5.880] 6.028| 6.069

“SES Gea j 8.391 | 6.520| 6.466| 6.246] 6169] 6.144

Here we see that the average of 1,000 corpuscles restored

and measured from stains of human blood is 7.910 mikrons,

all probably being stains from the blood of adults ; while the

average from fifteen persons (three being infants) is 7.938

mikrons, the maximum and minimum, where infants are

included, in fresh blood being a little more widely separated

than in the restored stains from adults. So also the range,

when taken by tens or twenties, is a little less for restored

blood than for fresh blood, for the same reason. No closer

similarity of results could have been expected had all the

measurements been taken from fresh blood, one set including

infants and the other taken from adults alone. The fact that

there is this difference given above goes to show the great

accuracy and perfect restoration of dried blood corpuscles to

their normal dimensions.

As a further confirmation of the possibility of restoring

dried blood stains to a condition in which their dimensions

can be properly compared with fresh blood corpuscles, we

copy, by permission, the following table from Professor

Wormley’s Micro-Chemistry of Poisons:

22 MOSES C. WHITE:

EXAMINATION OF OLD BLoop STAINs.

Animal. Age of Stain. Remarks. Average. | een

(1) Human .| 2 months old, | Stain unknown... . . gasy im. | gz'gp in.

Me ss alae: ours! ‘\ | Stam 2. 5... es. | eee ee

ee ves 3 « e RO ae ees a 2S | a en

(2) ee .| 19 ; is |, Clot 2. teres Late ree es in. lc in

(5) Elephant, | 13 13 an ae my mere meres | (co rials |) a Tia

(6) Dog .. 4 ns ‘* | Trace of stain unknown, | 3's, in. | gs457 in

(7) Rabbit .. | 18 a * 1 Clots... % Se © 2) slope lle eaten

($)-Ox 2) alae bt) (oe¢ Stain oo oe.

(9): Faced se a ‘| Stain unknown .. . . .| g2gg in. | gop in

(ro) |! 4S Yeats old . Clot... s+ + «| gegg in. | gotpy in

(11) Buffalo .|18monthsold .| ‘ ......... .|ggysin.| qizin

(12) (Goat cin ela 4. \sStaines 3397 iD. | aygg in

(13)"ibex as |ps “2 st Glot = - gers in. | gqgyz in

In the case of the human blood No. I, two months old, the deposit was in

the form ofa thin stain on muslin, and its nature, other than that it was mam-

malian blood, was unknown at the time of examination. The corpuscles were

readily found, and two series of thirty corpuscles were measured. In the

human blood two and a half months old, fifty corpuscles, ranging from 5,4; to

saa5 Of an inch were measured.

The blood stain of the dog, No. 6, was prepared by Dr. Frankenberg, and

consisted of a single stain so minute as to be barely visible to the naked eye;

its nature at the time of the examination was unknown. In the ox blood four

and a half years old, the corpuscles were readily obtained, and twoclosely con-

cordant series of measurements were made.

The table of Professor Formad, Collective Results of Some

of the Series of Measurements of Red Blood Corpuscles in

Blood Stains, in his article on Mammalian blood (/ournal of

Medicine and Surgery, July, 1888, copied in the MMedzco-

Legal Journal, Vol. X., p. 157), proves still further the suc-

cessful recovery and measurement of red corpuscles from dried

blood stains.

These tables show that blood corpuscles can be, and have

been, recovered and measured and found to correspond with

the average of fresh blood of the same animal from which

the stain was taken as closely as the corpuscles of any two

animals of the same species correspond when fresh.

The only remaining possibility of mistaking stains from

blood of a pig, ox, horse, sheep or goat for human blood,

THE RED BLOOD CORPUSCLE IN LEGAL MEDICINE. 213

when fifty or one hundred corpuscles have been measured and

found to average 7.9 mikrons, or even 7.0 mikrons, is to sup-

pose that the blood corpuscles have become larger than fresh

blood, or that the expert has wickedly and purposely measured

only the largest corpuscles and has not done honest work.

Professor Ewell says that ‘‘ by selecting the corpuscles it

would be possible for a dishonest observer to make the aver-

age much larger or smaller than the above given (in his table)

without the possibility of detection—a fact the bearing of

which upon the value of expert testimony upon this subject

is so obvious as to need no comment.” We have never

claimed, and shall not now claim, that it is any more difficult

for a witness to swear falsely in regard to blood stains than in

regard to any other subject. But it would be quite possible

on cross examination to ask the expert whether in measuring

the corpuscles obtained from a stain he had measured all the

well-defined corpuscles in the field of the microscope, or

whether he had selected the large corpuscles and rejected

others which were smaller.

In the case of State of Connecticut vs. Herbert H. Hayden,

Superior Court Special, October term, 1879, Dr. J. J. Wood-

ward, U. S. A., gave testimony for the defense in regard to

examination of blood stains.* He stated that in 1875 he had

published in the American Journal of Medical Science the

measurements of thirteen sets of human blood corpuscles,

about fifty in each set. The average diameter of the whole

series was 0.000295 inch. The largest set of fifty corpuscles

measured 0.000304 inch, and the smallest set 0.000295 inch,

but that he left out some of the larger corpuscles because they

were not perfectly circular, and that the result would give an

average rather too small for the general average of human

blood.

That he also measured nine sets of about fifty ina set from

the blood of a dog; the average of the nine sets from the

dog was 0.000290 inch. Some of the averages of fifty from

the dog were larger than some of the averages from men,

* Report of Court Stenographer printed by Black & Bryant, Boston, Mass.

214 MOSES C. WHITE:

though the average from all dogs would be smaller than the

average from all men. These were measured with an eye-

piece micrometer ruled on glass.

In 1876 he published in the Proceedings of the American

Medical Association measurements of twenty-two sets of cor-

puscles from men and thirteen sets from one dog. The aver-

age of all the sets from men, then published, was 0.000323

inch, which is larger than Gulliver's measurement of ,4, inch

by eleven millionths of an inch, but some of his averages of

150 corpuscles from a dog, published at that time, were also

larger than some of his averages of 150 in a set from men.

Allthe measurements above referred to, published in 1876,

were measured on photographic negatives.

Dr. Woodward also stated in the same case :

Within the last two or three weeks I have made a still further series of

measurements of man and dog. I used for the purpose a cobweb micrometer,

and the lens which of all other lenses in my acquaintance defines the best—

namely, one of the Zeiss lenses ; Zeiss of Jena.

With that lens and with a cobweb micrometer I made a series of measure-

ments of forty corpuscles of human blood—it was from one of the assistants in

the museum. I brought the corpuscle into the center of the field and I meas-

ured it with the cobweb micrometer, that is by turning the screw I set the

cobweb on the extreme limit of the corpuscle so that the cobweb line just

touched the edge on the outside, and then the readingsof the turns of the screw

gave the number of divisions.

I got an average of those forty corpuscles of 327 millionths of an inch—

This was fifteen millionths of an inch larger than 5355 of an inch. Now, in

these 40 corpuscles, the biggest individual was 366 millionths of an inch.

Then I pricked my own finger and took a drop of my own blood and I meas-

ured.fifty corpuscles, and there I got the average size to be 324 millionths of

an inch, that you see is three millionths of an inch smaller than I just got on

another set.

Then in another sample of human blood I got the figure 316 millionths of

an inch on the measurements of twenty corpuscles. This last figure would

differ only four millionths of an inch from Gulliver's 5555 of an inch.

I measured, on the 14th of December of the present month, fifty corpuscles

of the blood of a dog; it was a Newfoundland crossed with setter ; a pup four

weeks old. I measured fifty corpuscles, and the average was 326 millionths of

an inch.

Q. Differing, I see, only one millionth of an inch from the first forty cor-

puscles of human blood ?

A. Yes, and larger than my second fifty, larger than any of that set of

human measurements, except the first, and larger than any of the photographic

THE RED BLOOD CORPUSCLE IN LEGAL MEDICINE. 215

measurements I have published of dogs’ blood except one. Well, then I

measured another dog’s blood on the 12th of December, a Scotch terrier, forty

corpuscles, and I got an average of 320 millionths of an inch.

Q. That, I see, is larger than the last for human blood ?

A. It is larger than the last for human blood, and larger than the 5345, of

Gulliver.

Q. It is larger by eight millionths than Gulliver's average ?

A. Yes, sir; then alsoon the 14th of December I measured another dog's

blood, a Gordon setter, full grown, and his blood was smaller than either of

the young dogs I have spoken of, the average of twenty-nine corpuscles was

300 milhionths of an inch.

Q. Excuse me for asking you how much larger that is than your figures

published in 1875, of human blood ?

A. It is five millionths of an inch larger.

Q. Then, if I understand it, you measured several other dogs at this time?

A. Not at this time, those were all I measured at this time, and I desire to

put myself on record as distinctly denying that those measurements of the

dog’s blood would represent what you would be likely habitually to get if with-

out picking out young dogs, and without selecting a spot to measure appearing

to have unusually large corpuscles you were to measure dog’s blood. You

would then habitually get smaller figures than I have given here. The aver-

ages of the corpuscles of dogs would habitually be smaller than I have given

here, but I have purposely selected for fixed measurements young dogs, for I

knew they had bigger corpuscles, and, in the second place, in taking an old

dog, I purposely selected a place (on the slide) where, to my trained eye, I saw

there was a group of big corpuscles; that is the place on the thing I was

measuring. My reason for doing that is to show that if you pick up a half

dozen corpuscles at chance, you may chance on these big things. But I have

nowhere stated, on the contrary I would like to read my express statement

from my printed utterance, that the general average for the dog, for a great

number of measurements, will be less than for a great number of men.

Q. You have stated that your object in selecting these dogs, and these

large corpuscles of these dogs, was to show how it might innocently happen

that in the measurements of a given number of corpuscles, say twenty, or

thirty, or forty, or fifty, as you have here, you might get this large average ?

A. Yes, and you would get it if you stumbled upon such a group.

In relation to the dark border of the corpuscle, Dr. Wood-

ward said:

When you look at a blood corpuscle, for instance, in a microscope of high

power, there appears to be a certain thickness at the edge; there is

a certain dark shadow at its edge, and that has a certain degree of

thickness. Now, should you measure all the shadow as blood corpuscle, or

none as blood corpuscle, or shall you measure one-half of that shadow as blood

corpuscle? There is always more or less uncertainty about that. I myself

2716 MOSES C. WHITE:

have always thought, when the objective of the highest definition was used ;

when we had exquisite defining power, and when, in consequence, the shadow

which accompanies the corpuscle is more nearly round, you may safely bisect

it with the cobweb, setting one on one shadow and one on the other, soas to

take in a half shadow on each side as part of the corpuscle, but if you have

taken in the whole you would get slightly larger measurements.

On cross-examination by Mr. Waller, in regard to the

shadow or dark border of the corpuscle, Dr. Woodward said:

A. My opinion is that about one-half of that line is shadow.

Q. Iask you now, in your measurement, how much of that doubtful quan-

tity that we call shadow, do you include in your measurement of the corpuscle?

A. I always include half of the surrounding dark area.

In treating blood stains with solvents of fibrin, to liberate

the corpuscles for measurement, it has been found in many

cases that the corpuscles were smaller than in fresh blood,

unless maceration was long continued, old stains requiring

several weeks before the corpuscles were in a condition to be

measured. When a bi-concave blood corpuscle is placed in

water, the coloring matter (hemaglobin) is dissolved out, the

corpuscle swells up, thickens at the edges, becomes trans-

parent and spherical. In this condition the diameter of the

corpuscle becomes less than normal. It thus happens in

examining blood stains that all corpuscles which have lost

their color or have become spherical are by some experts

rejected and not measured. Some corpuscles in fresh blood

have much more coloring matter than others, and these cor-

puscles retain their color and form (as we think) much longer

than paler corpuscles. We are not aware that any fluid used,

or likely to be used, for softening blood stains, will cause the

corpuscles to become larger than normal. This point, I

admit, requires further investigation.

If the corpuscles obtained from a stain do not recover their

normal dimensions, it is almost absolutely certain that their

average measurement will be less than normal and never

greater than normal. Thus, in the language of Professor

Wormley, we may confidently say: ‘‘ Thus then, whilst the

blood of man might, on account of contraction in diameter of

THE RED BLOOD CORPUSCLE IN LEGAL MEDICINE. 217

the blood corpuscles, be confounded with that of some animal

having smaller corpuscles, the reverse could never occur.”

Professor E. S. Wood in lWaetthaus & Becker's Medical

Jurisprudence, Vol. IL, p. 42: ‘‘ There is noreagent that

we know of at the present time, and no influence outside of

the living body, which tends to increase the diameter of the

red corpuscles.”

From this discussion we claim that it has been proved

beyond any reasonable question :

1. That in favorable cases blood stains can be so treated

that reliable measurements and credible diagnosis of their

origin can be given, as shown in the tables given and in

others which might be referred to.

2. That if error occurs on account of imperfect restora-

tion of the form and diameter of the corpuscles obtained from

a stain proved [by (a) the Guaiacum test, (4) the spectro-

scope, (c) by the production of hemin crystals] to be blood,

the error, if any, will be to make human blood appear like

that of one of the inferior animals, and never to mistake the

blood of the ox, pig, horse, sheep or goat for human blood.

3. In general, when a stain has been proved to be blood

by the above tests, it may be decided certainly whether it is

or is not mammalian blood. So, also, a stain from the blood

of the ox, pig, horse, sheep and goat may be distinguished

from human blood: thus confirming the claim of an accused

person in many cases that his clothes are zof stained with

human blood. This negative testimony is certainly quite as

important in many cases as testimony inculpating a prisoner.

Lastly, the expert can say, when the average of a suitable

number of corpuscles from a blood stain corresponds with the

average of fresh human corpuscles, that the stain is certainly

not from the blood of the ox, pig, sheep or goat; and in

other cases he can say, with great certainty, that a given

stain is not human blood.

Such testimony, by a skilled microscopist, is of untold

importance in saving the lives of the innocent, and often in

218 THE RED BLOOD CORPUSCLE IN LEGAL MEDICINE.

overthrowing the plea of those who are guilty. Such testi-

mony is quite as reliable and important to the welfare of

society as that of the chemist who testifies to the presence or

absence of poison that might have some resemblance to the

many recently discovered ptomaines.

NoTE.—All the photoengravings in the following pages

which are represented as magnified x 2560 are from nega-

tives on wet plates by J. B. Treadwell, M. D., of Boston.

Those magnified x 10850 diameters are enlargements made

by the writer from the negatives x 2560 of J. B. Treadwell.

Plate x 840 and all marked x 640 are from photographs

made by the author, and show very clearly the appearance

seen in ordinary good microscopes of moderate power at the

present day. M.. Cy We

Human Blood, Red Corpuscle—X 10850.

Red Blood Corpuscles of Goat—X 10850.

ae ai” ed

Red Blood Corpuscle, Pig—X 10850. Red Blood Corpuscle, Pig, Medium—X 10850.

Small size.

* :

{

Red Blood Corpuscles of Man—X 2560. As seen when out of focus.

Red Blood Corpuscles of Ox—X 2560.

—X 2560

Red Blood Corpuscles of Horse

Human Blood Corpuscles (Pernicious Anemia)—X 2560.

Red Blood Corpuscles, Man (Anemia)—X 600. Very small and generally

small size. Photo. by W. N. Sherman, M. D., of Merced, Cal.

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Blood of Man—X 640. Blood of Guinea Pig—

X 640.

Blood of Pug Dog—X 640.

Blood of Man—xX 640.

Blood of Bull Dog—-X 640.

Human Blood: -X 640.

Blood of Young Calf—X 640.

X 640.

Human Blood—

Blood of Ox—X 640.

X 640.

Blood of Man

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Human Blood—X 640. Blood of Cat—X 640.

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Human Blood—X 640. Blood of Ass— X 640.

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Blood of Man—X 640. Blood of Sheep—X 640.

YEASTS AND THEIR RELATION TO MALIGNANT

TUMORS.

ALLEN ROSS DEFENDOREF, A. B., M. D., WorckstTEr, Mass.

Since the possibility of a parasitic origin of cancer, as well

as other tumors, was suggested by Paget,’ who likened the

growths produced upon trees by the stings of insects to the

tumors of men, almost every pathologist of any renown has

investigated the subject.

A critical investigation of the voluminous literature on this

subject impresses one with the fact that something is at fault,

for when almost all are united in asserting the presence of

‘‘Cancer Bodies,” yet few have dared to tell us just what they

are. The fault lies in the fact that, with a very few excep-

tions, research has been conducted only on a historical basis.

Six years of investigation have shown that from the mor-

phological standpoint, there is no hope of establishing the

specific cause of these neoplasms, for, since the promulgation

of Koch’s laws, scientists in mycology have been loath to

accept as the cause of disease, organisms which do not con-

form to its requirements.

The recent discovery of the fact that the class of fungi

called yeasts are pathogenic has opened up a new field.

Since this discovery by Sanfelice, in 1893, the subject has

aroused much interest, especially among the Italian and Ger-

man pathologists, so that now the yeasts which meet the

requirements of Koch’s laws are to receive a large share of

the attention which was so lavishly bestowed upon the sup-

posed protozoan parasite.

Yeast fungi, also called B/astomycetes, are the chief repre-

sentatives of the genus Saccharomyces. It is to be regretted

that their exact botanical position has not been determined.

220 ALLEN ROSS DEFENDORF :

Formerly they were considered as a stage in the development

of filamentous fungi, but now authorities agree that they form

a distinct class.

Morphologically they are round or oval cells, arranged

singly, or in chains, increasing by budding or by spores, and

occasionally forming mycelia. Each cell consists of a mass

of granular protoplasm, surrounded by a double contoured

membrane. The younger forms are, forthe most part, homo-

geneous, while the older forms contain one or more refractive

granules.

The cells as they are seen in animal tissues are somewhat

different, in that they usually possess refractive granules,

and a membrane varyingin thickness. Insome cases they are

surrounded by another double contoured hyaline membrane.

The protoplasm is usually hyaline. The mother cell rarely

gives rise toamycelium, which is considered an abortive form.

Much discussion has arisen in regard to these refractive

granules, whether or not they are or represent nuclei. Raum

says that he could never establish a nucleus. Sanfelice says

that the granules cannot be compared to such a nucleus as

we findin a fully organised cell. Though they stain more

deeply than the protoplasm, they cannot on account of their

lack of consistency be called nuclei, and besides, they have

never been seen to take part in the process of budding (except-

ing Sirleo and Maffucci). They are persistently present in

all kinds of Blastomycetes, but they present no constant

attributes as to form, arrangement, number orchanges. They

were observed by Schwarm and de Legues, also by Rees and

Hausen, and were called endospores, a view which Raum,

Moller and Brefeld justly opposed.

Yeasts stain equally well with any of the aniline dyes, also

with carbofuchsin, and hematoxylin (Bisse). The methods

of staining are as follows :

The tissue is stained in toto with lithium-carmine for

twenty-four hours, twenty-four hours in alcohol acidified with

1 per cent of hydrochloric acid, treat with absolute alco-

hol as long as stain is removed, clear with xylol, imbed

YEASTS AND MALIGNANT TUMORS. Z21

in paraffine, free sections of paraffine with xylol, treat with

absolute alcohol, let stand from five to fifteen minutes ina

flask filled with Ehrlich’s solution, wash with water, treat with

a few drops of 5 per cent. oxalic acid, which acts asa mordant,

wash off the acid with water, treat with absolute alcohol as

long as the color is removed, clear in xylol, mount in balsam.

By this method, which was selected by Sanfelice because

of the beautiful colors, the tissue ground work is stained red

and the parasite violet.

In Ehrlich’s fluid, methylene-blue or malachite-green can

be substituted for gentian-violet, when the parasites are

colored respectively blue and green. If the tissue is stained

in sections, the following is a good method.

The section freed of paraffine is stained ten to fifteen

minutes, or one to three hours in the following solution :

Saturated watery solution of Safranine ......... Tap:

Saturated alcoholic solution of Malachite-green. ... . iy p.

Distiledswater sam Meisee kee Natt CR) -arseta ee Sanew eee y p.

Wash in distilled water, treat five minutes with 5 per cent.

oxalic acid, wash, treat with absolute alcohol, clear in xylol

and mount in balsam.

By this method the parasite is stained green or bluish-

green according to the length of time the tissue is allowed to

stand, the protoplasm flesh-red and the nucleus safrin-red.

In place of the staining fluid, mentioned in the above

method, the following solution may be substituted :

Saturated watery solution of Safranine . ... ... 5-6p.

Saturated alcoholic solution of Gentian-violet . . ...Ip.

IDEN Cl at 5 5 6 oO ple 6 6 oS HS SS Sa BS X{ p.

Leave the specimen in the staining fluid three or four

minutes, which stains the parasite violet and the tumor the

high reds of safranine.

Good results can be obtained from a mixture of borax

carmine and indigo carmine. After staining, the sections are

treated with a saturated solution of oxalic acid. The para-

sites stain blue and the tumor red.

222 ALLEN ROSS DEFENDORF :

Gram’s method may be used, but the solution of iodine

must be very weak, so as not to decolorise too strongly.

Yeasts are widely distributed throughout nature. Bre-

feld’ found them in air, dust, plants, leaves, fruits and

manure. The most difficult part in the study of these fungi

has been to get them to grow on nutrient media and to

isolate them, so as to procure pure cultures. Their behavior

in culture growth resembles very much that of bacteria,

which exhibit a few characteristics in common, but present

individually their peculiar reactions in different media. They

prefer acid media, in which they grow very slowly. They

do not liquefy gelatine. Potato is a favorite medium, upon

which their growth is usually luxuriant. A common charac-

teristic which most of them possess is the ability to produce

alcohol in sugar cultures. An idea of the manner of their

growth on the different media can be obtained in the study

of some of the pathogenic varieties. They do not produce

toxins, but those which produce pathological effects do so by

means of general infection.

Since the discovery of the yeasts, in the early part of the

century, they have been identified with the process of ferment-

ation, in which they are the active agent. It was not known

until the studies of Newmayer’ and Raum‘ that they possessed

pathogenic qualities.

Raum, who inoculated ten rabbits seventeen times with

the Cereveus and the Elizpsoideus, found that death resulted

when large quantities were inoculated. Quantities of the

parasites were found post-mortem in the lungs, where they

had produced thrombosis. In one instance, a tumor was

produced in the ear of a rabbit injected intravenously, which

proved a caseous mass containing fungi.

Sanfelice,® although he had done much work on the mor-

phology of Blastomycetes, as he prefers to call them, did not

study their pathological effects until the latter part of 1894,

when he found that a certain variety which he had isolated

was pathogenic in pure cultures for guinea-pigs, sheep, rab-

bits, rats, sluts and pigeons.

YEASTS AND MALIGNANT TUMORS. 223

Because of the similarity of the colonies of this B/lastomy-

cete on solid media to those described by Cuboni and

Pizzigonni as characteristic for the Saccharomycetes ellipsot-

deus, Sanfelice placed them in the genus of Saccharomyces

and on account of the pathological changes he called them

Saccharomycetes neoformans.

The culture growths were as follows: On_ gelatine

plates the surface colonies, about the size of a pin-head and

cup-shaped, were white in color, while the colonies below

the surface were smaller, spherical, with a yellowish-white

color and a well-defined margin. The medium was not

liquefied, and whether neutral or acidified with I per cent.

tartaric acid, offered an equally good soil. Under a micro-

scope of high power, the cells were easily distinguished,

packed very closely together. Colonies on agar plates pre-

sented the same appearances asabove. In gelatine stab cul-

tures the growth was luxuriant, both on the surface and along

the stab. On the surface of slant agar, neutral or slightly

acidified, they produced a finely granular, dry, non-glistening

membrane, which very slowly covered the whole surface.

On the potato it had the appearance of a white, lusterless

membrane, with warty prominences, but a smooth border.

The growth was luxuriant in milk, but produced no change

in the medium. In fluid media, to which different kinds of

sugars had been added—glucose, maltose, dextrose, lactose

and saccharose—there was arich growth, producing no tur-

bidity, but oftentimes there was found on the surface a more

or less thick white membrane. Dried preparations of media,

stained with the watery or alcoholic solutions of aniline dyes,

showed the greater number of cells to be stained intensely,

throughout their entire structure. A few were stained more

intensely at the periphery, while one large or several small

deeply stained granules lay in the center. Examined in the

hanging drop, these cultures by careful observation showed

the process of budding.

The observations of Sanfelice upon the pathogenic quali-

ties of this variety of yeast were made from inoculations of

224 ALLEN ROSS DEFENDORF:

guinea-pigs with pure cultures. The fungi were scraped from

the surface of an agar or potato culture, mixed with a small

quantity of sterilised water and immediately inoculated.

Cultures from each of the solid media were equally virulent.

Age had no effect upon the virulence, for cultures five months

old were no more virulent than fresh cultures. In all, forty

guinea-pigs were inoculated subcutaneously, into the testi-

cles, into the liver and into the peritoneal cavity, with fatal

results. Those which ingested the pure culture showed no

apparent effect. With the exception of the last, all died in

about thirty days, only two living longer; one forty-three

days, and another seventy-five days. Of those inoculated

subcutaneously, there appeared in the adjacent connective

tissue a tumor, which was as large as a hazel nut. Withina

short time after the inoculation, the lymphatic glands in the

inguinal and axillary regions began to enlarge. At the

autopsy the tumor seemed to be composed of a firm white

tissue and was adherent to the skin. The lymphatic glands

of the axillary and inguinal regions were greatly enlarged

and exhibited a tissue similar to that of the tumor. Upon

opening the abdomen the spleen was found to be enlarged

and covered with white spots. The liver and lungs were

enlarged and with the kidney, showed similar white spots on

their surfaces. :

Guinea-pigs inoculated in the testicles showed at the

autopsy swellings of that organ, together with changes in

the abdominal cavity, much the same as those of the animals

inoculated subcutaneously. In the guinea-pigs inoculated in

the peritoneal cavity, the organs of the abdomen and thorax

were more profoundly involved than in those inoculated sub-

cutaneously or in defined organs. In the cavity there was a

severe peritonitis, which might have been called neoplastic,

and the surface was covered with a milk-white fluid. Tumors

the size of a hemp seed, white in color, were found on the

parietal peritoneum and the omentum. The lymph glands

were enlarged.

The tissues of the guinea-pigs, when fixed, hardened,

YEASTS AND MALIGNANT TUMORS. 225

stained and mounted, showed interesting changes. The

tumors at the site of the subcutaneous inoculation presented

a nest of young connective tissue, in the meshes of which a

varying number of cellular elements, which were very simi-

lar to lymph corpuscles, and whose nuclei laid mostly at the

periphery of the cell body. Among these elements there

were so many parasites that the tumor seemed to be due

rather to the presence of the parasites than to the tissue

elements.

The fungi were mostly free, and well stained, though a

few were without a trace of stain. Their size varied greatly.

Among the very young forms no membrane was seen; in

forms of medium size there was a hyaline membrane, and in

the oldest forms there was a deeply stained membrane. The

last forms correspond in the fresh preparations to the forms

with strongly refractive membrane.

The granules were usually deeply stained, though in some

cells which had undergone degeneration nothing within the

membrane had taken on stain. The protoplasm of some cells

showed very clearly the two kinds of protoplasm stained to a

different degree. Among the very large forms were seen

some with avery clear hyaline membrane outside, but no

trace of an inner membrane.

The tumors of the guinea-pigs inoculated in the liver

seemed due rather to the presence of large numbers of the

parasites than to any great change in tissue elements.

Aggregations of yeasts corresponded to the white spots and

granules scattered on the surface of the organ. These groups

were found not only under the capsule but also in the paren-

chyma.

The tumor of the great omentum in the guinea-pigs inocu-

lated in the peritoneal cavity presented the same structure as

those noted above—namely, numerous fungi lying between

the meshes of a loose connective tissue, which was in some

places thickened, but otherwise normal. Many parasites

were found also in the pancreas and salivary glands.

In the kidneys they were more numerous in guinea-pigs

226 ALLEN ROSS DEFENDORF :

inoculated into the peritoneal cavity than into the subcuta-

neous tissue or into special organs. The situation by prefer-

ence seemed to be in the cortex and inside of the increased

connective tissue, corresponding to the white spots seen by

the naked eye. Groups of the parasites had destroyed parts

of the convoluted tubules. They were seen in the loops of

the glomeruli, and, as a consequence of the rupture of the

glomeruli, had escaped into Bowman’s capsule. By this it

was proved that in the kidney, at least, they spread through

the blood.

The number of parasites was much larger in the lungs of

the guinea-pigs inoculated in the peritoneal cavity than sub-

cutaneously. They were found in larger numbers in the

lungs than in any other organ. They laid in the spaces

between the alveoli, and caused a considerable increase of

tissue.

This variety of yeasts was of less importance on account

of the pathological conditions which it produced than because

of the morphological similarity which its forms presented to

the structures, which have been described by the many

authors on malignant tumors of men as belonging to the Pro-

tozoa.

Sanfelice has since discovered several varieties of yeasts,

which he has not yet described fully, but which he claims

belong to the group of Weoformans. Whether or not they

are pathological he has not determined. He has, however,

succeeded in two cases, one of an epithelioma of the lip and

the other in an epithelioma of the mammary glands, in secur-

ing pure cultures of yeast fungi, which he has proved by

inoculations to be pathogenic to animals.

Sanfelice’ remarks upon the neoplastic growth in a slut

inoculated in the mammary glands with a pure culture of

another yeast, that a tumor was produced at the site of

inoculation, and also that there were metastatic tumors in

the intestines and in the spleen. In the connective tissue

which surrounded the gland, groups of cells were noticed,

some of which possessed a large nucleus pressed to the peri-

YEASTS AND MALIGNANT TUMORS. 227

phery, and other smaller nuciei similarly disposed. The

cells were packed together in rows which crossed each other,

giving the appearance of a fibrous carcinoma. From these

groups radiated outward rows of cells which seemed to bur-

row between the connective tissue fibers. There was no

evidence of inflammation. The parasites could not be found

in the center of these groups, even by the most careful

searching. Cells at the periphery, however, contained them,

where they appeared to be in the early stages of growth,

mostly without membranes. The histological structure of

the new growths in the other organs was of a similar charac-

ter to that in the breast. The yeasts were situated in the

cytoplasm of the cells, were round, and possessed the char-

acteristic double contoured membrane. With this variety

an inoculation was made between the leaves of the comb of a

rooster, and caused a neoplasm, which approached in charac-

ter asarcoma. The sections of the tumor showed that the

larger number of the yeasts was in the central part of the

tumor. Many of the parasites were degenerated, and so

stained lightly. The tissue of which the tumor was com-

posed consisted of young connective tissue elements, among

whose bundles lay many cells with intensely stained nuclei

and sharply defined cell bodies. In some places these cells

produced thick bands, among which could be perceived

isolated yeast cells.

In May, 1895,‘ Sanfelice isolated a variety of yeasts from

an ox which had died of primary cancer of the liver and sec-

ondary invasion of that process into the whole lymphatic

system. Pieces of the enlarged glands were applied to the

different fluid and solid media and a culture established.

By teasing pieces of the glands in a fluid consisting of equal

parts of glycerine and water, yeasts were found in large

numbers, of different sizes, mostly round and possessing a

tefractive membrane. Most of them contained refractive

granules. Near these parasites were found many others of

an appearance which the Slastomycetes ordinarily give inside

of the cells. They were homogeneous and of a glassy refrac-

228 ALLEN ROSS DEFENDORF :

tibility, or of that sort of refractibility which calcareous

bodies present in pathological tissues. Besides these forms

there were irregularly formed masses witha sharp outline and

a calcareous refractibility, which he at first considered to be

calcareous degeneration products.

Plate cultures of gelatine showed colonies of yeasts which

on the surface were round, white and of the size of a pin-

head, but beneath were smaller, spherical, sharply defined

and of a yellowish color. Stab cultures in gelatine showed

colonies both on the surface and along the stab. On slant

media the colonies were white, elevated and of a dried

appearance. Examined microscopically, they appeared as

round cells, of different sizes, according to the age of the

culture, and with glistening granules ; but the glassy-looking

bodies, described above, could not be found,

From the culture growths and the microscopical appear-

ance, the yeast seemed in no way different from the patho-

genic variety, named Saccharomycetes neoformans, and

described above.

Guinea-pigs inoculated subcutaneously with an emulsion

of pieces of the glands and sterilised bouillon died in two

months and showed the following pathological conditions:

The axillary and inguinal lymph glands were enlarged ;

the great omentum showed a few small nodules the size of a

hemp seed ; a few were seen also in the spleen; the lymph

glands of the abdomen were also enlarged; small nodules

were seen in the lungs ; the liver, intestines and brain exhib-

ited no changes. When inoculated intraperitoneally, condi-

tions identical to those just described were found.

Small pieces of the lymph glands of the dead guinea-pigs,

teased and examined fresh under the microscope, showed

parasites both free and enclosed in the cell elements of the

gland. They disclosed the characteristic membrane, while

some of them had amore or less hyaline halo surrounding

the membrane. The protoplasm was homogeneous with

the usual number of refractive granules. Besides these nor-

mal forms were seen others, which refracted the light like

YEASTS AND MALIGNANT TUMORS. 229

glass. These were degenerate forms of the fungi. In the

kidney they were present in such numbers that upon section

it seemed as if the organ was full of calcareous deposits. It

was noticed with those guinea-pigs which died a greater

number of days than usual after the inoculation that the

reaction on the part of the tissue was greater, from which

fact it was concluded that after some time, if the animal sur-

vives, the parasites tend to degenerate and disappear.

Sanfelice gave this variety of yeast fungi the name of

Saccharomycetes litogenes, from the appearance of calcare-

ous degeneration which it gave. The Saccharomycetes

litogenes were pathogenic also for white rats, rabbits, sheep

and cattle.

Shortly after the first contribution of Sanfelice appeared,

Maffuci and Sirleo® described a pathogenic yeast fungus which

they obtained from a guinea-pig that had died of marasmus.

They were successful in establishing pure cultures, which

upon inoculation into guinea-pigs gave fatal results.

The parasites were found in the lung, kidney and lymph

glands. They observed that the structure of the cellular

tissue was the same in all of the above organs, and similar to

that which was described above, in Sanfelice’s investigation.

They noticed, however, a greater activity in the formation of

new structure in the lungs than in the other organs. This

dissimilarity may be explained by a longer time, which the

parasites had acted before the death of the animal, which

fact was not mentioned.

Otto Biisse® discovered a pathogenic fungus in the study

of a malignant tumor of the tibia of a woman, which during

life was diagnosed as a sarcoma, but by post-mortem

examination appeared as a form of chronic pyemia, with a

number of giant cells. They appeared in the pus among the

giant cells as small, clear, refractive, round or oval bodies,

of a size varying between that of a small nucleus and a liver

cell. They were also found as cell enclosures within the

giant cells. At first, they were looked upon by Professor

Grawitz as belonging to the group of Microsporidia, being

230 ALLEN ROSS DEFENDORF :

Cornalia’s bodies or Coccidia. Later, as the result of positive

culture, they were identified by Professor Loffler as a kind of

pathogenic yeast fungus. The possibility that he might be

dealing with a variety of Coccidza, as the descriptions and

drawings of Darier and Wickham suggested to him, led him

to try a culture in sugar bouillon, which produced alcohol.

This left no doubt that the parasites were yeast fungi.

He injected into the marrow of the tibia of a rabbit a

small piece of the tissue taken from the tumor. The leg

became gangrenous in three days and was amputated, when

it was found that the whole length of the tibia was beset

with yeast cells, which proved that the yeast cells had the

ability to multiply in human tissues. Some of the pus from

the tumor was injected into the peritoneal cavity of a rabbit,

with fatal results in three days. The mesenteric glands were

much enlarged and in them were found the parasites in large

numbers.

The fact that Biisse published his results a month after his

first inoculation, before some of his test animals had begun

to show the effects of the inoculation, or before their tissues

had been examined histologically, prevented him from draw-

ing any other conclusion than that the yeasts were capable of

multiplying in animal tissues.

Ajevoli” and Pianese"™ have done work which could not be

obtained.

Corselli and Frisco” succeeded in isolating a pathogenic

yeast from a case of sarcoma of the mesenteric glands with a

milky exudate. At the autopsya neoplastic mass was found,

consisting of enlarged mesenteric glands with many small

tumors, of the size of a lentil, situated on the diaphragm and

small intestines, and a quantity of milky fluid in the abdomen

and thorax, similar to that seen during life. | Microscopical

examination of the fluid, made during life, showed cellular

forms of different sizes, some small, others the size of a liver

cell, mostly round, which were isolated or in groups, very

often of four. Most of them showed one or more granules.

They stained by the usual methods.

YEASTS AND MALIGNANT TUMORS. Zoe

Inoculations of the pathological material were made upon

the ordinary media, but neutral or alkaline focus was the only

one upon which a culture grew. From this medium colonies

of the Blastomycetes were isolated and transferred to gelatine,

simple agar, glycerine agar, and sugar agar, and also bouillon,

where the culture flourished. A microscopic examination of

the pure cultures showed the fungus to be of a larger size

than those in the pathological material, though in respect to

the refractive granules no difference was noticed. The cells

were surrounded with a thin membrane. The protoplasm

was usually homogeneous, with a granular appearance at

some places. In the hanging drop were seen small granules,

which increased in size and approached the appearance of

round bodies, and which later became still more prominent

on account of their different refractive contour and their dif-

ferent disposition toward stains. Finally, they burst the

membrane and became free, assuming the first stage of the

parasite. The more usual means of propagation was that of

budding. Another unusual form was that of forming a rod-

like appendix, which showed the tendency for producing a

mycelium.

The results of the inoculation of guinea-pigs, rabbits and

dogs, with both the pathological material and the pure cultures,

were uniformly fatal. The guinea-pigs inoculated with five

cubic centimeters of the milky fluid, or two cubic centimeters

of aten-day bouillon culture, died in about thirty days. The

lymphatic glands of the mesentery were greatly enlarged.

At other places in the mesentery appeared numberless groups

of ball-like nodules. Similarly many little nodules were

found along the line of the lymph channels, in the axillary

and inguinal regions. A microscopical examination of these

nodules disclosed a structure similar to that found in the

woman, except that mycelial forms of the fungi were very

rare. Rabbits inoculated with five cubic centimeters of the

fluid, or five cubic centimeters of the bouillon, died in from

thirty to thirty-five days. The same appearance, macrosco-

pically and microscopically, were noted in the guinea-pigs.

232 ALLEN ROSS DEFENDORE :

Of the dogs which were inoculated intravenously and intra-

peritoneally, one died in five days without any apparent

changes. The parasite was regained only from the blood of the

heart. One of the dogs inoculated intraperitoneally, showeda

tumor of the mesentery, the size of a small hen’s egg, and

lymph nodules as large as white beans along the spine and in

the peribronchial glands.

The facts that negative results were obtained in the cul-

tures of the parasites in the juices from fruits, that there was

a slight tendency to grow on acid media, and a failure to

produce alcohol in saccharin fluids, influenced the investiga-

tors to conclude that during their life as parasites in the

tumors of animals, they naturally suffered a change in their

mode of life, and acquired a character qualified for their para-

sitic existence in animals. .

From these observations it follows that this Blastomycete

caused among the inoculated animals neoplastic growths of a

malignant character.

Observations have been made by Roncali® upon Blastomy-

cetes, but only from a histological standpoint. He found

them in the cytoplasm of certain cells, similar to those of a

corpus luteum, which were present in the stroma of an adeno-

carcinoma of the ovary. The tumor, the size of a child’s

head, consisted of three cysts, which contained a slimy fibro-

serous fluid. On the inner wall of the cysts, and floating in

the fluid, there were found little bodies of different sizes with

a cauliflower appearance. Histologically, these neoplasms

consisted of a ground-work of connective tissue, from which

there were numerous ramifications lined with cylindrical epi-

thelium. In the enlarged cell bodies of the epithelium were

found the parasite. The cell protoplasm was granular and

the nucleus usually apparent. In some cells the nucleus was

pushed to one side and hardly distinguishable, and in others

the protoplasm appeared as if vacuolated. The parasites in

great numbers were both within the cells and free in the con-

nective tissue, most of them, however, in the former condi-

tion. Very many of the cells contained a single parasite,

YEASTS AND MALIGNANT TUMORS. 233

though some of them had as many asten. These cells were

swollen, with the nucleus shoved to one side. The form of

the parasites was round, rarely oval or kidney-shaped. They

varied in size, some being larger and others smaller than the

nucleus of acell. They were always within the cell proto-

plasm, never within the nucleus. A capsular membrane sur-

rounded them, which appeared as a hyaline circle. The

younger forms possessed no membrane. No nucleus was

found. The younger and growing forms were more numer-

ous than the old and degenerate ones, as the latter, he con-

sidered those forms which did not stain, but appeared pale

and refractive.

Twelve weeks after the operation for the removal of the

adenoma, the patient died. At the autopsy many metastatic

tumors of the diaphragm and omentum were found. The

omentum was thickened and on its surface appeared several

nodules of different sizes and of greyish-white color, which,

upon being incised, appeared compact and of pearly white-

ness. By microscopical examination, many parasites were

found in these metastatic tumors. They were similar to

those found in the primary lesion, with the exception

that only a few older forms were seen. A number was

extra-cellular, when they appeared in groups of from seven

to thirteen, surrounded by leucocytes or epithelial ele-

ments.

Roncali failed completely in the production of pure cul-

tures. From the histological examinations, he concluded

that these cells were a variety of ASlastomycetes, because of

their close identity to forms seen by the many other investi-

gators. Naturally, Roncali comes to the conclusion that there

is an etiological connection between the primary adeno-carci-

noma and the secondary metastatic tumors of the omentum and

the mesentery, from the fact that the parasites which were

nested between the bundles of connective tissue and in the swol-

len epithelial cells of the tumor, are likewise found in the

mestastic tumors, both in the epithelial cells and among the

fibers. Another important fact is that only younger and

234 ALLEN ROSS DEFENDORF :

growing forms were present in the metastatic tumors, and the

older and degenerate forms in the primary tumor.

Roncali,”“ in trying to establish the etiological relation of

yeast fungi to sarcoma, made histological examinations of

five sarcomas. The first, a large round celled sarcoma of the

crest and body of the ileum; the second and third, spindle

celled sarcomas somewhat melanotic, from the orbit; the

fourth and fifth, large spindle celled sarcomas of the superior

maxilla, also somewhat melanotic. His results were as fol-

lows : in five tumors from different locations and in different

tissues, he found in every case parasites. They resembled

morphologically the forms which Sanfelice had described.

They took the stains of the Blastomycetes and withstood the

action of acids and alkalies. “They were found both inside

and outside of the cells. They multiplied by budding.

Some were found in youthful stages without a membrane,

with highly colored protoplasm ; and others older, with a

thick membrane and a somewhat chromatic heterogenous

protoplasm which had lost the faculty of staining.

Colpi,”’ claims to have found a variety of yeasts in a case

of chronic endocervicitis, which acted as the etiological

agent. But from the fact that he could in no way produce

fermentation with it, authorities believed either that it was.

not a yeast, or if it was, it represented a degenerate form.

Other Italian authors, Claudio, Fermi and Aruch,” have

worked on this subject and have concluded that there isa

pathological yeast, whose chief characteristic is to produce

neoplasms of a chronic nature, whose cellular elements had

the property of wandering away from the neoplasm into the

lymphatic glands. They isolated their yeast from a horse

affected with an infectious kind of lymphangitis, and found

by inoculations that it was markedly pathogenic.

Lydia Rabinowitsch,” under the direction of Koch, has

studied the action of fifty different varieties of yeast on test

animals. Of these only seven were found to be pathogenic,

and none of those were from culture yeasts. Inoculations of

the culture yeasts proved fatal in mice and rabbits only after

YEASTS AND MALIGNANT TUMORS. 235

immense doses, and even then only a few parasites were

found in the tissues.

She concludes from her research that none of the

pathogenic varieties were identical to those which had been

described by the other authors. In her cases it is probable,

from the fact that the yeasts were more plentiful in the blood

than in the organs, that death was due to the infection. In

the dead animals most of the cells were found free in the

tissue, only a few being seen in the cell elements.

On a gelatine plate culture of pus, taken from an appendix

removed by Professor Carmalt, a colony of yeast fungi was

found, which the author studied. In gelatine stab culture

the growth appeared in the form of the needle along the

whole stab. On gelatine plates they formed a small white

globular colony, which spread very slowly without liquefying

the gelatine. On slant agar the colony, which spread more

rapidly than on gelatine, presented a pearly white appear-

ance. On potato the growth was quite luxuriant, giving a

yellowish-white appearance. Examined in the hanging drop,

the cells were found to be mostly round or oval, consisting of

a granular mass of protoplasm, which was surrounded with a

double contoured membrane. Stained with methylene-blue,

the protoplasm of the cell showed deeply-stained granules.

Because of the lack of material, no inoculations were made to

ascertain whether the yeast was pathogenic. Consequently

the results are of little value ; however, had a like discovery

been made two years ago it would have been regarded as an

accidental inoculation from the air. Now, with the knowl-

edge that yeasts have been found in the pus of a sarcomatous

sub-periosteal tumor and in a sarcoma accompanied with

Ascites chylosus, there is reason to believe that this specimen

of the yeast fungi, when inoculated into test animals, may

prove to be pathogenic.

Reviewing the whole field of research on this subject, what

conclusions can be drawn, first, as regards the yeast fungi in

their relation to animal and human tissues ; and second, in

regard to their relationship to malignant neoplasm ?

236 ALLEN ROSS DEFENDORF:

(a.) Yeast fungi are known to invade the tissues of ani-

mals and men, where they subsist in the same manner as

bacteria.

(o.) Certain varieties of yeast fungi are pathogenic

through infection to animals, among which are dogs, pigeons,

horses, cats, rabbits, guinea-pigs and mice.

(c.) They are present in diseased conditions of the human

tissue.

Before trying to establish any relationship between the

yeast fungi and malignant tumors, it is necessary to review,

with that idea in mind, the work of the several investi-

gators.

The investigation of Roncali is, perhaps, of the least real

value in this problem, because he dealt with the question from

a histological standpoint only. His case of adeno-carcinoma of

the ovary with metastatic tumors in the mesentery, presented

what he believed to be yeast fungi. The fact that they are

fungi he infers from their marked similarity in shape, size and

appearance under the influence of stains, to the forms which

Sanfelice has proven to be yeasts. His investigation of the

five cases of sarcoma was of the same nature. In all cases

he found bodies identical to those which other authors have

isolated from sarcoma, inoculated into test animals, and

caused tumors similar histologically to the original one.

Busse succeeded in isolating a pure culture of a yeast,

from a sarcomatous sub-periosteal tumor of the tibia. This

he found to be pathogenic to animals, and in the case of an

inoculated dog to cause a tumor. His observations were not

very complete, as he published his paper before the tumor

had been examined histologically. Although there is no

direct evidence as to what the tumor was, yet we are war-

ranted in inferring, from results obtained by other men, that

if it had been examined the presence of yeast fungi would

have been determined.

The observations of Maffucci and Sirleo are of importance,

because they succeeded in producing neoplasms in all of their

test animals, for which their fungi were pathogenic. They

YEASTS AND MALIGNANT TUMORS. 237

were among the first to suggest the possibility of the yeast

fungi being the cause of malignant tumors.

Corcelli and Frisco present results of the utmost import-

ance. They succeeded in procuring a pure culture of a Slas-

tomycete from a tumor, which, both during life and at the

autopsy, showed itself to be a malignant neoplasm. This

caused, among the test animals, tumors which were identical

to the original tumor, both in location and structure. It is

certainly easy to establish an etiological relationship here.

Furthermore, with the discovery of this parasite, equipped

with the power to cause malignant tumors, there is opened a

new field in the study of Ascztes chylosus and the connection

which exists in man between these tumors and the exudate.

To Sanfelice we are indebted, more than to any other

investigator, for our present knowledge of pathological yeast

fungi. The uniformity of his success in producing tumors

among the test animals with all of his pure cultures is most

remarkable. This fact, together with the notable similarity ~

of the yeasts in the tissues of the animals which had been

inoculated, to the so-called Cocczdia of many authors on the

cause of cancers, led him to investigate malignant growths,

with the result that he succeeded in making pure cultures of

yeasts from a case of carcinoma of the breast and one of car-

cinoma of the lip. These cultures, by inoculation, proved

pathogenic.

The results of Lydia Rabinowitsch, who found only seven

pathogenic varieties of yeast among fifty, which in no case

produced tumors, somewhat temper the results of the other

investigators. None of her yeasts produced neoplasms, and

none of them were pathogenic to guinea-pigs although to

other animals. These results are not of so much importance

when we consider that of all the yeasts known four years ago

only two varieties were found by Sanfelice to be patho-

genic.

The results of Fermi and Aruch, who produced a pure

culture from a horse affected with an infectious lymphangitis

and proved it pathogenic, add evidence not only to the patho-

238 ALLEN ROSS DEFENDORF:

genic character of yeast fungi but also to their ability to pro-

duce malignant growths.

Almost all the investigators of yeast fungi have alike been

impressed with the marked similarity which exists between

the yeasts as they appear in tissues and the numerous forms

of cancer bodies, as they have been described and pictured

by the many writers on the parasitic nature of malignant

tumors, especially carcinoma. With this fact in view, it

seems best to consider them here and, if possible, to show

that they represent in the tissues a variety of yeasts.

After the suggestion offered by Paget, in 1887, at various

times, several authors, as Rappin,” Scheurlein,” Brault,” Sen-

ger,’ Baumgarten,” Rosenthal” and Kubasoff* described vari-

eties of bacteria as the specific cause of cancer, but the

discovery of similar microorganisms in non-cancerous tissue

led to the belief that their presence in those cases was merely

an incident.

The apparent protozoan nature of certain bodies in epithe-

lial formations, such as Molluscum contagiosum, described

originally by Virchow’ and a number of other investigators,

among them Rivolta,” Bollinger,” Neisser,” suggested the

likelihood of the existence of cancerous bodies in the allied

cancerous formations.

In 1888, Pfeiffer described Sporozoa, and Malassez,” in

1889, announced the discovery of bodies resembling Cocczdia

oviformes in the cells of the epithelioma of the jaw.

About the same time Thoma” described small cell-like

bodies found in the epithelial cells of glandular cancers of

the rectum, breast and stomach, all of which, and especially

the latter, might be, from their description, easily confounded

with yeasts.

Albarren” found round bodies in the epithelia, which he

described as psorospermes, a greater part of which he says

had the form of round or little egg-shaped cells, also possessing

a single central nucleus. Some of the parasites were clearly

encapsulated with a membrane of varying thickness. There

were others which were very refractive and homogeneous with-

YEASTS AND MALIGNANT TUMORS. 239

out nuclei. One could scarcely need a better description of

the Blastomycetes found by Sanfelice in the tumors of the

guinea-pigs which had been inoculated with a pathogenic

variety of yeast fungi. The latter part of the description

tallies precisely with the form which the degenerated L/asto-

mycetes take on.

Darier® found, in a certain skin disease, Psorospermosts

follicularis vegetaris, round, intra- and extra-cellular bodies

with a thick refractive membrane. His figures correspond

exactly with drawings of yeasts.

Wickham, a scholar of Darier, found similar bodies in

cases of Paget’s disease. His drawings also were like those

of yeasts.

Nils Sjobring,* who had been studying the process of

nuclear division in cancer cells, had noticed certain bodies

which he called Protozoa. The cycle of development, so well

described and pictured by him, can be easily explained by

stages in the development of the yeast fungi.

These descriptions of Albarran and Sjobring were soon

corroborated in publications of Balbiani,*” Hacks,*® Wright,”

Strobe,** Steinhaus” and Kursteiner.*

Soudakewitch" found in the cells and cell nuclei of glandu-

lar cancers small round or oval bodies, sometimes with a

membrane about them. Metchnikoff, who also examined

‘them called them Coccidia. His drawings are very similar, in

some respects, to those of authors on Alastomycetes.

Sawtschenko and Podwyssozki™ failed to notice parasites

within the cell nucleus, but in most cases found them in the

cell bodies.

Sawtschenko* described the apparent life history of the

so-called Sporozoa from sections of a cancer of the lip. Here,

also, both the descriptions and drawings of these stages

resembled very closely conditions of the yeasts.

Foa* studied especially carcinoma of the breast and men-

tioned small bodies, which were usually homogeneously

but sometimes contained deeply-stained central granules,

-also larger forms, which might reach the size of a white blood

240 ALLEN ROSS DEFENDORF :

corpuscle. They were surrounded with an intensely stained

capsule. He also described forms which, had he not been

looking for Cocctdia, might have been explained as Blastomy-

cetes in the process of budding. Other forms, which present

a striking resemblance to these, were those which he described

as not staining. Whether this was due to degeneration he

was unwilling to say.

Koretneff,*® Kurloff,** Smith” and Clarke* describe forms

of a gregarine-like body, which they claim is the fully devel-

oped form of the parasite, and to which the name of Rhopalo-

cephalus carcinomatosum was given. An undeveloped stage

of this parasite, which was found most frequently in the sec-

tions, resembles very much the yeast fungi.

These are the only writers who have recognised gregarine-

like forms as a factor in the etiology of the epithelioma.

From the fact that they were found only in relation to pearls

of epitheliomata of the lip or penis, it seems as if they had

mistaken degeneration products for genuine organisms.

Buchardt* studied cancers of the mucous membrane and

found in most of them intracellular structures surrounded

with a clear capsule.

Ruffer and Walker” confirmed the investigation of conti-

nental workers and, later, Ruffer’’ announced that he had

seen every stage in the life history of the Protozoon of can-

cer, from the time the parasite appeared as a spore in the

nucleus until it left the latter as a young, fully formed parasite.

Galloway” has recently announced his belief in the proto-

zoan nature of the various bodies described, on account of

their apparently organised structure, their staining reactions

and their analogy to well-known Protozoa. He figures them

as small round masses of protoplasm, which may become

encysted and then break up into a number of sporules.

Of all the authors who have busied themselves with the

parasites of malignant tumors, Russel’* is the only one who

has described a fungus as the real cause. These, because of

their affinity for acid-fuchsin, he calls ‘‘fuchsin-bodies,” and

states that they may be found in cancers without exception.

YEASTS AND MALIGNANT TUMORS. 241

These bodies may occur in groups of two, three, four or

more ; generally have a clear space about them ; are bounded

by a capsule ; are spherical in shape, measuring from four to

twelve mikrons in diameter, and are structureless in appear-

ance. He judged that they grew by gemmation. They

were found in the more rapidly growing part of the tumor.

Realising the weakness of a parasitic theory of the origin

of cancers, which is unable to comply with Koch’s laws, sev-

eral investigators have attempted to inoculate cancerous tis-

sues into test animals. Hanan made a successful inoculation

of carcinoma taken from the vulva of one rat into that of

another, producing not only a similar tumor but also metas-

tasis. Fuschel tried inoculation experiments, but failed.

Klebs, in his inoculation experiments, found that the parts

were absorbed. Power” assumed that the parasites, as in

malaria, were propagated in soil, and collecting soils from

districts which were evidently cancer districts impregnated

them with cancerous tissue. On these, white rabbits, which

had been subjected to irritation on different parts of their

bodies were compelled to live for some time. His results

were also negative.

Pathologists have succeeded in finding parasites in sar-

coma as well as in carcinoma.

Vedeler,” after the study of four sarcomas, comes to the

conclusion that probably the numerous cell enclosures which

he found were Sporozoa. His drawing of the stages of their

development compared with those found by Bisse are very

significant ; and, with the description of yeasts by Corselli

and Frisco, cause one to be impressed with the marked simi-

larity of forms which were found by those authors, both in

the original tumor and in the tumors produced in the test

animals.

Pawlowsky,” in his study of fourteen cases of sarcoma,

came to the conclusion that the parasites which he found had

an etiological connection with the spreading and growth of

the tumors. In the description of the life history of the

parasites, he maintained that the spore was the starting

242 ALLEN ROSS DEFENDORF :

point. His drawings also show strong resemblance to the

yeast fungi described by Corselli and Frisco, as well asa

similarity in form to those shown by Bisse.

Steinhaus, Hadden, Wernicke, Jackson and Clarke are

other pathologists who have recognised similar parasites in

sarcomas.

In the author's investigation of tumors the specimens were

prepared as follows: Taken in most cases absolutely fresh,

and in some still life-warm, they were cut into pieces, five

cubic centimeters in size, and placed in a saturated solution

of corrosive sublimate at least three hours, but no longer

than twenty-four. (The fixing solution was prepared by

adding to boiling distilled water as much corrosive sublimate

as would dissolve. Upon cooling the supernatant fluid was

not decanted, but placed in a dark bottle. The solution will

keep only two weeks, and must be placed where it is cool.)

After being washed they were removed to 70 per cent. alco-

hol, where, with daily changes, they remained a week. The

strength was then increased daily to 80, 95 and absolute

alcohol. Then the specimens were cleared in oil of Berga-

mot for twenty-four hours, then in xylol twenty-four hours,

and finally placed in xylol and paraffine, and paraffine alone.

The sections were cut as thin as possible. Besides the stains

of eosin and hematoxylin, the Ehrlich-Biondi triple stain,

safranine and malachite-green, lithium-carmine and Ehrlich’s

fluid with gentian-violet were used; but the most beautiful

results were derived from the following method: Place the

slide for twenty-four hours in a dilute solution of Delafield’s

hematoxylin (2 per cent. is found strong enough), wash in

water twenty-four hours, changing frequently ; leave in gen-

tian-violet and aniline-water twenty-four hours, wash thor-

oughly ; differentiate quickly in acid alcohol, then a moment

or two in eosin alcohol ; dehydrate quickly in absolute alco-

hol, clear in xylol and mount in balsam.

With a few exceptions, parasites were found in all the

specimens examined. These included specimens from

eighteen schirrus cancers ofthe breast, five recurrent cancers

YEASTS AND MALIGNANT TUMORS. 243

of the same variety from the same region, two cancers of the

penis, one from the upper lip, one schirrus cancer from the

mesentery and one from the stomach, one round-celled sar-

coma of the stomach and one of the breast. Of these, the

results of the research in a few selected tumors will be taken

to represent the study of the whole.

In a case of carcinoma of the penis there were seen numer-

ous cell enclosures, which stained similarly to yeast fungi

found in cancerous tissue by Sanfelice and Roncali. Some

were found in vacuoles and others showed no differentiation

from the cell contents but that marked by the stain. A few

were found which presented deeply-stained granules. Many

of them were so small that they did not change the contour

of the nucleus, while a few were of such proportions that the

nucleus was not only crowded to the periphery of the cell but

was pressed into a crescent shape. Besides those bodies

which appeared as real parasites there were found numerous

other bodies of forms similar to those described by some of

the authors mentioned above. Among these forms were sev-

eral specimens similar to the so-called Rhodalocephalus

Carcitnomatosum, of Koretneff, which bodies, from the

appearance presented in the sections of the writer, could

be more readily explained as products of degeneration than

as parasites. Steinhaus has described the process by which

the cells are gradually pressed together until they become

degenerated masses, which upon section may present many

different shapes that might be taken for parasites. In this

case of carcinoma of the penis the arrangement of the cells

about these masses suggested the existence of pressure, the

cells in contact with the mass were very thin, much like the

superficial cells of the epidermis, there remaining only the

evident outline of the cell, without a nucleus. The next lay-

ers of cells were thicker, and many of these possessed dis-

torted nuclei, and finally, toward the periphery, perfectly

normal cells were seen. Bodies were found which corres-

ponded very closely to some of those described and drawn

by Foa, which seemed more like cell invaginations.

244 ALLEN ROSS DEFENDORF:

Many parasites were found in the schirrus carcinoma of

the breast. These were similar in form and size to those

drawn by the various authors who have described the yeasts.

In a case of schirrus carcinoma of the stomach and the

metastatic tumors from the axilla, parasites were found, which

were identical in form, size and in their reaction to staining

reagents. They were uniformly round, homogeneously

stained and situated within vacuoles. Ina case of a round-

celled sarcoma of the stomach, besides forms similar to those

mentioned above, there was found a form which was under-

going what seemed to be a process of budding, being similar

to those forms described by Roncali in his research.

In comparing the yeast fungi and the parasitic bodies of

malignant tumors, something ought to be said in regard to

the staining reactions of the latter. Opponents of the para-

sitic theory claim that all of the appearances presented by

the so-called Protozoa can be explained by the staining reac-

tions of the different kinds of cell metamorphoses, as hyaline,

colloid, gelatinous and horny degenerations ;. or by irregu-

larities of cell life, as cell invagination, vacuolisation, dropsy

of cell bodies, irregularities in the distribution of chromatin

and dispersion of chromosomes, fragments of such during

and after the karyokinetic process and asymmetrical mitosis,

or they can be explained by the inter- and intracellular inva-

sion of leucocytes and red blood corpuscles. While their

statements may be true in the case of many forms which

has been presented as parasites—for, at one time or another,

no doubt, every one of the irregular forms mentioned above

have been pictured among parasites—yet a greater part of

them cannot be explained away by any method of staining.

In fact, our knowledge of the reactions of the different

products of degeneration toward stains is so meager that

neither side can disprove claims of the other in many cases.

A specific stain has not been found for Protozoa or yeast

fungi, so that staining reactions are of little value in procur-

ing evidence in support in either class of bodies.

Most of the forms, as we have seen, which have been

YEASTS AND MALIGNANT TUMORS. 245

described by investigators as cancer bodies, can as readily be

considered as yeast fungi. As regards the remaining forms,

it may be said that, in order to obtain the knowledge that

they were dealing with Protozoa, they were compelled to

hunt for forms which were not present, and consequently

christened as such bodies which were not parasitic.

Finally, in drawing our conclusions as to the relationship

of these fungi to the malignant tumors of man, we may say

that :

First—From a histological standpoint, we probably have

as evidence the results of the investigations of those who,

for the past eight years, have upheld the parasitic theory of

malignant tumors, men who have seen yeast fungi, but have

incorrectly called them Protozoa.

Second—From the researches of Sanfelice, Corselli and

Frisco, and Bisse, that yeast fungi have been found in man

and the lower animals affected with malignanttumors. These,

isolated, grown on nutrient media and inoculated into other

animals gave rise to malignant tumors, which showed the

same characteristics as the original tumors.

The field of research is but just opened and the investiga-

tions confined to a few centers of learning ; still, with the

main obstacle overthrown—namely, compliance with the laws

of Koch, it seems that we are much nearer to the solution of

that difficult problem, the etiology of malignant growths.

246

CMI AM

ALLEN ROSS DEFENDORF :

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Surgical Pathology. Brit. Med. Jour., 1887.

Landw. Jahrbiicher, Bd IV., S. 405.

Untersuchungen iiber die Wirkungen der verschiedenen Hefearten welche

bei der Bereitungen weingeistiger Getranke vorkommen auf der Thier-

ischen und Menschlichen Organismus, 1890.

Zur Morphologie und Biologie der ee ange Zeitschrift fiir Hygiene

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Annali dell’ Instituto d’ Igiene della R. Univ. de Roma, Vol. IV., 1894,

Il Policlinico, 1895.

Centr’! fiir Bak., Bd. XVIII., Nov. 9, 1895.

I] Policlinico, Anno 2 Marzo, 1895.

Ueber Parasitare, Zelleneinschliisse und ihre Ziichtung. Centr’! fiir

Bak., Bd. XVI-., S: 175-

Il Policlinico, Sept. 1, 1895.

Giorn. internaz. d. Scienzie mediche. 15 Juni, 1895.

Centr’! fiir Bak., Oct. 15, 1895.

Il Policlinico, and Annales de Micrographie, 1895.

Die Blastomycetes in den Sarkomen. Centr’l fiir Bak, Bd. XVIII., Oct.

26, 1895.

Hefezellen als Krankheitserreger im weiblichen Genital-kanal. Archiv.

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Ueber eine neue pathogene Hefeart. Centr’! fiir Bak., Bd. XVII.,1895.

Untersuchungen iiber pathogene Hefearten. Zeitschrift fir Hygiene und

Infectionskrankheiten. Bd. XXI., Dec. 6, 1895.

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Deut. med. Wochensch., Bd. XLVIII., 1887.

Archiv. gen de med., Bd. 11. S. 586, 1885.

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Centr’! fiir Bak., 1888.

Zeitschrift fiir Hygiene, 1888.

Wiener med. Presse, Bd. XXXI., S. 1890.

Virchow’s Archiv., Bd. XXIIL., S. 149.

Dei parassiti vegetali. Turin, 1878.

Virchow’s Archiv., Bd. LVIII.

Vierteljahrschrift fiir Dermatologie, Bd. XV., 1888.

Die Protozoen als Krankheitserreger, S. 189, zweite Aufl., 1891.

Les tumeurs de la vessie. Paris 1892.

Fortsch. der Med., June, 18go.

Sur des tumeurs epitheliales contenant des psoro-spermies.

Comp. rend. de la Soc de biol., p. 265, 1889.

Annales de Dermatologie et de Syphilographie. Tx p. 597, 1889.

Ein parasitarer protozoen-artiger Organismus in Carcinomen. Fortsch.

der Med, 1890. Bd. VIII., S. 529.

Virchow’s Archiv., Bd. CXV., Hft. L.

Comp. rend. de la Soc. de biol , 1890.

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YEASTS AND MALIGNANT TUMORS. 247

Virch. Archiv., Bd. CXXVII., Heft 1, and Bd. XLI., Heft 3.

Virch. Archiv., Bd. CXXX, Hft. 3.

Ann. de 1’ Institut. Pasteur, 1892—'93.

Centr’l fiir Bak., Bd. XI., S. 93.

Centr’! fiir Bak., Bd. XII.

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Centr’l fiir Bak., Bd. XIII., No. 11 and No. 12, and Sporozoen als Krank-

heitserreger Berlin, 1893.

Centr’! fur Bak., Bd. XV., No. 1o and No. 11.

New York Med. Jour., Jan 5, 1895.

Centr’! fiir Bak., Bd. XVI., S. 281.

WVireh.Archiv,, Bd. ©€XXXI., S. 121:

Brit. Med. Jour., Vol. II., p. 113, 1892.

. Brit. Med. Jour., Nov. 5, 1892.

Brit. Lancet, No. 5, 1893.

Brit. Med. Jour., Dec. 13, 1890.

Brit. Med. Jour., 1894, Vol. II., p. 636.

* Virch. Archiv., 1893, Bd. CXXXIII., S. 464.

Centr’l fiir Bak., Bd. XVI., S. 849.

A STUDY OF THE CELLULAR PATHOLOGY OF

CARCINOMA.

CLIFFORD WALCOTT KELLOGG, M.D., New Haven, Conn.

It is not the intention of the writer, in the following paper,

to enter at all into a general discussion as to the etiology of

cancer. Todo so, in the present state of our knowledge,

would be simply to theorise, to indulge in useless speculation,

adding rather to the mist of obscurity that enshrouds the

origin of these growths than being of any practical or sugges-

tive value.

This mist of obscurity, however, it may be said, is no denser,

the veil no thicker than that which up to a comparatively

recent period enveloped a number of the diseases with which

mankind is afflicted, diseases which we now know to depend

upon the presence of a specific organism. One after another

of these so-called ‘‘ microbic affections” have yielded, in so far

as the causative agent is concerned, to the careful, patient

investigations of the pathologist. There are still many, how-

ever, that remain refractory, refusing as it were to disclose

the secret of their birth; and among them, overshadowing

all perhaps, in the matter of importance to human kind is the

one now under consideration—carcinoma.

The genesis of cancer is no longer in doubt; the studies

of Waldeyer and of Thiersch having demonstrated almost

beyond the possibility of question that it involves that of

epithelium generally. Aimless, purposeless, destructive

growths then, the proliferative and infiltrating elements of

which are epithelial cells—cells always derived from preéxist-

ing epithelium, standing invariably in a direct genetic relation

to tissues originating in the epiblastic or hypoblastic layers

of the blastoderm.

THE CELLULAR PATHOLOGY OF CARCINOMA. 249

In so far as this, our knowledge of the pathology of can-

cer may be said to be accurate ; but here it practically ends.

The question now is, and the answer is all important : What

furnishes the stimulus for this aimless, infiltrative growth of

epithelial elements ? What causes these tissue cells to leave

their normal situation and by a process of excessive multipli-

cation and proliferation not only to force their way into the

lymph-spaces of adjacent structures, but to reproduce them-_

selves in even remote parts of the organism ?

Theories without number have from time to time been

advanced, our works on pathological science teeming with

them, admitting, the while, that they are but theories. Thus

long-continued mechanical irritation has been assigned as a

cause ;—the failure of an organ, like the female breast, to

perform its physiological functions;—developmental faults, as

the aberrant embryonic remains of Cohnheim ;—errors in

nutrition dependent on trophic neuroses ;—loss of balance, in

after-life, between the connective and epithelial tissues, with

insubordination of the latter (Thiersch) ; all of these and a

host of others have been assigned a place among the etiologi-

cal factors, and in a certain way, perhaps, they may all be

entitled to such a place. For example, long-continued

mechanical irritation is unquestionably, in very many cases,

associated with cancer ; as witness the often quoted scrotal

cancer of the sweeps, the arm of the paraffin worker and the

cancer of the lip in smokers of clay pipes. In thousands of

such cases, however, of prolonged irritation no cancer appears,

and, fer contra, in hosts of cases of cancer no history of such

irritation can be obtained.

In view of these last considerations, we are certainly justi-

fied, for the present at least, in holding to the opinion of

Cohnheim; that while most if not all of the factors mentioned

have a place in the pathology of carcinoma, they tend rather

to produce a constitutional, or it may be a local predisposi-

tion to the disease than to act, per se, as primary or prolifera-

tive causes ; that a certain weakening or diminution of the

normal physiological resistance of the tissues is produced,

250 CLIFFORD WALCOTT KELLOGG:

whereby morbid influences, at other times wholly inoperative,

are enabled to produce their characteristic effects.

Billroth rather aptly defines this vague ‘‘ predisposition”

as a ‘‘specific formative irritability” of the tissues ; while the

acting morbid influence is referred to as a ‘‘ specific formative

stimulus.” Adopting, then, Billroth’s terminology (The

Mutual Action of the Living Animal and Vegetable Cell.

New Sydenham Soc., 1894,) as the more explicit of the two,

it would seem as though we are warranted, as has been said, in

considering that the various forms of irritation, e¢ a/., act by

producing a ‘‘ specific formative irritability” rather than as

‘specific formative stimuli.” And yet for the production in

various and varied situations of neoplastic formations as spe-

cific and unvarying in type as cancer, there must exist a form

of stimulus, and a far-reaching and a continuously-acting

stimulus that cannot be considered as otherwise than specific.

There are some features that characterise the growth of a

carcinomatous tumor that seem to point to an analogy between

them and certain other tumor formations that were some

years ago classed by Virchow as ‘‘infective granulomata.”

Thus, that which was said by Dr. Green of a tuberculous

deposit may with slight modification be equally well said of a

cancer nodule: ‘‘ The progressive character of the growth

and its tendency to infect adjacent and distant portions of the

body show the existence of some irritant capable of multi-

plying in the body and of spreading from primary to second-

ary foci.”—Green, Pathology and Morbid Anatomy. Seventh

Am Cap 5 5A:

This resemblance to a tuberculous process, this tendency

to spread from primary to secondary foci, taken in connection

with the characteristic cachexia that marks the progress of a

carcinomatous growth, has led to the belief, now more or

less widely spread, that cancer itself is of an infectious

nature, even though its inoculability from man to man be not

absolutely proven. Add to these features a certain observed

tendency to hereditary transmission, if not of the disease

itself, to atleast a predisposition to the disease, and it is lit-

THE CELLULAR PATHOLOGY OF CARCINOMA. 251

tle to be wondered at that the belief in an infective or para-

sitic origin should have become, in the minds of some path-

ologists at least, quite firmly implanted.

This idea having taken root, it is hardly necessary to state

that a most active search for the infective agent has for a

number of years been carried on ; with results that are cer-

tainly interesting, not to say startling, even while they aston-

ish one by their variety.

Inasmuch as this paper has to do with some of the appear-

ances that in a measure give color to this theory of parasitism

in cancer, it may be well to state here that the bibliography

upon the subject is already enormous ; so much so that any

extensive reference to it is unnecessary and in a limited

space impossible. With the exception, then, of a few casual

allusions, the writer will content himself with a more or less

imperfect demonstration of what may be found here at home

in specimens of cancer met with in ordinary routine work.

In 1888, it will be remembered that Neisser, of gonococcus

fame, published an elaborate paper embodying the results of

his investigations into this subject, and placing the ‘‘ para-

site,” which he described, in the Cocczdza group of the Sporo-

‘goa. (Vierteljahrschrift fir Dermatologie und Syphttes,

1888.) A little later (Br7ztzsh Medical Journal, December

13, 1890,) Dr. W. E. Russell, of the Royal Infirmary, Edin-

burgh, described and depicted a so-called parasitic organism,

presenting the appearance of round, homogeneous bodies,

staining deeply with basic fuchsin and retaining it strongly

when treated with other reagents, such as iodine-green.

These he denominated ‘‘ fuchsin bodies,” considering them

of a fungoid nature.

Contemporaneously with these, and continuing up to the

present time, a host of other observers have described micro-

scopic appearances attributed to result from the presence of

an organism ; some considering it to be a Fungus or Alga,

others a Protozoon. .Thus, Soudakewitch, Pio Foa, Thoma,

Metchnikoff, Korotneff, G. Sims Woodhead, Ruffer, in con-

junction with Walker and Plimmer, C. H. Castle and a host

252 CEIFFORD WALCOTT KELLOGG :

of others have, from time to time, described appearances

that, whether dependent upon the presence of a parasite or

not, demand, from the very importance of the subject, the

closest study on the part of every student of pathology.

The assumption, on the part of these observers, that we

are dealing with a parasitic organism, has, as is to be

expected, met with a storm of criticism from pathologists of

the highest repute. Thus, Klebs, Cornil, and, in our own

country, Welch, of Johns Hopkins University, Prudden, of

New York, and others, while admitting the appearances

question the probability of their being due to a parasite, and

ascribe them to various sources, to which we will refer later.

Looking, however, at the matter from both points of view,

weighing the evidence as we get it from the literature, pro

and con, and it becomes at once manifest that we are not by

any means justified in taking too radical a stand upon this

subject ; that there must be something to warrant the opin-

ion of such men as Pio Foa, Thoma, Russell, Ruffer and

G. Sims Woodhead, and, such being the case, careful and sys-

tematic study is the course that should be pursued, rather

than the maintenance of a position of sceptical inactivity.

The feature that strikes one most forcibly, on looking over

the various articles upon this subject, is the lack of uniformity

in the results obtained. And it is this very feature perhaps

that more than any other leads conservative minds to main-

tain a sceptical attitude, and it was this feature that led, in

part, to the series of investigations that form the basis of this

article; one of the objects having been to ascertain what there

was in the microscopic appearances of cancer that should lead

Dr. Russell to describe a round, homogeneous ‘‘ fuchsin

body” as a Fungus, while Neisser described a Protozoon ;

albeit the boundary line between the two is by no means

well defined.

In addition to this, the writer, in making these investiga-

tions, hoped to be able to satisfy at least himself as to the

following points:

1. Whether in the specimens of cancer met with in ordi-

PE SCL LUULARS PATHOLOGY OF CARCINOMA. 253

nary class-room and routine work, without special methods of

hardening and fixing, microscopical appearances could be

found that might be interpreted as indicating the presence of

an organism or body foreign to the tissues.

2. Whether these appearances are to be demonstrated in

all specimens of carcinoma.

3. Whether they are peculiar to the carcinomata alone.

The possibility of being able to definitely determine the

nature of these bodies was also considered, but it must be

admitted, scarcely hoped for.

In selecting the material for these studies it will suffice to

say that, with a few exceptions, it was taken from the ordi-

nary material provided for laboratory work in the Medical

Department of Yale University, under the supervision of Pro-

fessor M. C. White. A few specimens, however, were per-

sonally prepared by the writer from tissues derived from

various sources.

As to methods of fixing and hardening, they were various;

chiefly, however, a simple passing of the tissues through

alcohols of progressive strengths ; as, for example, 55 per

cent, 67 per cent., 75 per cent., 82 per cent. and finally into

95 percent., in which the specimens were kept. Oneor two

specimens, involving nervous tissues, were hardened in

‘*Miller’s fluid, while one or two were fixed in a saturated

solution of corrosive mercuric chloride for an hour, thence

passing through progressive strengths of alcohol, as above.

It will thus be seen that ‘‘ especial methods of fixing and hard-

ening” can hardly be said to be a predominant factor in the

production of the appearances about to be described.

With regard to embedding and cutting of sections, all of

the methods in common use were employed ; thus, some were

embedded and cut in paraffin, some in celloidin and some

were cut by the aid of the freezing microtome.

As to the methods of staining, a few words may well be

said, although they will be made as few as possible.

Inasmuch as the first studies were devoted to the ‘‘fuch-

sin bodies” of Dr. Russell, the methods of staining employed

254 CLIFFORD WALCOTT KELLOGG :

by him were naturally first made use of. He, it will be

remembered, stained his sections first in a 2 per cent. solu-

tion of basic fuchsin in 5 per cent. carbolic acid; they were

then placed in at percent. solution of iodine-green (Gribler’s)

which replaced the fuchsin in everything but the above men-

tioned bodies. (Op. cit.)

The writer soon found that practically the same or better

results could be obtained with fuchsin and methylene-blue ;

there being no difficulty in demonstrating, in many sections

of carcinoma, the rather characteristic, deeply stained, homo-

geneous bodies referred to. . They vary in size from four to

eleven or twelve micro-millimeters in diameter, and are met

with singly, in twos, or threes, or in clumps of four or five

lying both within the protoplasm of the cells and in the

intercellular spaces. They are not confined, however, to the

carcinomata for a section of lympho-sarcoma now at hand

shows them in large numbers.

Not wishing at this time to devote much space to these

bodies the writer would suggest, in taking leave of them,

that they certainly merit close study. Red blood corpuscles

readily take up and strongly retain basic fuchsin; and there

are certainly in some of these ‘‘fuchsin bodies” appearances

that suggest red corpuscles. There is, however, rarely so

much variation in the size of the corpuscles, and they are

almost never found within the cell protoplasm, although the

writer has in one or two instances so found them.

Again the variation in the size of the ‘‘fuchsin bodies”

serves as no real basis of distinction. As is well known we

may have in certain pathological conditions the greatest

diversity in the size and appearance of the red corpuscles.

Thus in chlorotic conditions and pernicious anemia the so-

called microcytes and macrocytes, as well as the huge

‘‘oiganto-blasts ” of Eichhorst, twenty micro-millimeters in

diameter, are of frequent occurrence. For all this the writer,

after careful study, is not disposed, for many reasons, to

regard these ‘‘fuchsin bodies” asred blood corpuscles ; their

precise nature, however, it is impossible at present to state.

THE CELLULAR PATHOLOGY OF CARCINOMA. 255

While still engaged in the study of these bodies, with

other reagents than methylene-blue and fuchsin, certain

appearances presented themselves from time to time, in some

sections of carcinoma, that were not explainable by ordinary

methods of reasoning. For instance in staining with such

combinations as hematoxylin and safranine, hematoxylin

and acid fuchsin, and hematoxylin and eosin there appeared

to be certain enclosures in some of the larger epithelial

elements that differed in appearance from the cell nuclei,

and also from the bodies previously described ; and yet the

differentiation was not sufficiently well marked, both nuclei

and enclosures staining with hematoxylin, to warrant an

expression of opinion as to their nature.

Without going too much into detail it will suffice to say

that in the attempt to further differentiate these enclosures

there was no staining reagent, or combination of stains in

common use, but that was made use of, with, however, but

indifferent success. At length attention was directed to an

article or paragraph in Landois’ Physiology (4th ed., p. 389,)

on the beautiful results to be obtained in the demonstration

of the nuclear figures that appear during the process of mitotic

or indirect cell division (karyokinesis) by the use of a reagent

now widely known as the ‘‘ Ehrlich-Biondi” triple stain.

A trial of this reagent soon showed that by its use the

enclosures mentioned above, the cell nuclei, and in fact, all

of the component parts of the tissues could be differentiated

with almost diagrammatic effect.

This ‘‘Ehrlich-Biondi fluid,” as it was formerly called,

owes its introduction really to Haidenhain; and is a mixture

of methyl-green, methyl-orange or orange G. (Gribler), and

acid fuchsin; (Rubin S. ‘‘saure fuchsin”). It is prepared

by ‘Gribler in a dry form ready mixed for use, 100 cubic

centimeters of a 0.4 per cent. solution, with the addition of

7 cubic centimeters of a 0.5 per cent. solution of acid fuchsin

(both aqueous) making the ordinary desk reagent. The

method of using is given in nearly every recent work on

histology.

256 CLIFFORD WALCOTT KELLOGG:

Staining with this reagent secundem artem, using thin

sections, cut in paraffin and with careful attention to

technique we are told to expect the following results: the

nuclei to appear of a bright green, the cell protoplasm taking

an orange red or a reddish orange, while the connective

tissues appear of the vivid or crimson red of the fuchsin.

Briefly, while we expect these results we don’t always

get them. At the best the stain is an uncertain one, acting

at times and with certain tissues in a most inexplicable way.

In this the experience of the writer coincides, I think, with

that of most microscopists. At the same time, with all its

uncertainties, it is a most invaluable aid in histological

studies ; a well stained section presenting a beautiful picture,

and one that as has been said is almost diagrammatic.

Attention may be called to the fact that certain methods

of hardening are not compatible with the use of this stain ;

thus in sections hardened in ‘‘ Miller’s fluid” the cell nuclei

appear of a peculiar blue color, while the protoplasm appears

of a rosy red, lacking, however, entirely in orange. Again

embedding in paraffin seems to produce the only perfect

results, inasmuch as sections cut in celloidin rarely show any

orange in the protoplasm, unless it be after excessively long

exposure to the stain. Embedding in paraffin, however,

in itself leaves, in many cases, much to be desired. In

tissues particularly of an encephaloid or purely cellular type,

a marked and detrimental shrinkage is sure to take place.

With celloidin this does not occur; and in such tissues it is

vastly to be preferred. The slight differences in staining

incurred by its use, are after all but differences of degree ;

and to one at all practised in histological work in no way

impair the usefulness of either the reagent or method of

embedding. *

Returning now to the enclosures that have been referred

to as occurring in certain of the epithelial cells of some

sections of cancer, we may consider the appearances pro-

duced by the use of this ‘‘ Biondi” reagent.

These, in the main, do not differ from those above

' THE CELLULAR PATHOLOGY OF CARCINOMA. 257

described ; but there appear in many of the cells, bodies that

stain differently, and in other ways present an appearance

entirely unique.

These enclosures appear to be of two kinds. Thus some

of them appear to possess a distinct capsule or wall of a

vivid red color, a protoplasm that remains colorless and a

small distinct nucleus either centrally or laterally placed and

which is also of a bright red. They are almost invariably

contained within the cell protoplasm, it being very unusual

to find them extra-cellular in position. They are found

singly, in groups of two and three, or more, while in some

cases the cell appears crowded with them, the nucleus being

displaced or, as occurred in one instance, having entirely dis-

appeared. In size they vary from scarcely more than two or

three micro-millimeters in diameter up to twelve, or possibly

fifteen or even more.

The other form presents an appearance entirely distinctive

from this. In the first place they are never so small, rarely

falling below twelve micro-millimeters in diameter. They

are also perfectly spherical, have a small distinct nucleus,

but the protoplasm stains most decidedly; appearing of an

indescribable lilac color, or of even a distinct bluish red ; the

nucleus itself being of a more decided red. They are rarely

found otherwise than one in a cell, although two cells con-

taining them may be closely approximated. They never

appear in groups.

Reference to the accompanying plates will give a better

idea of these enclosures than could be obtained from pages

of text.

The sections from which these drawings were made were

taken from perhaps six or eight selected specimens of carci-

noma, including both primary and secondary growths. - All

of these, I think, with one exception, were removed by Pro-

fessor W. H. Carmalt, at the New Haven hospital, during

the past year. This exception, and the one most prolific in

the matter of ‘‘enclosures,” was a secondary growth of an

‘encephaloid,” or purely cellular type, involving the cere-

258 CLIFFORD WALCOTT KELLOGG :

bellum and resulting in death. The primary growth was a

scirrhus cancer (fibro-carcinoma) of the breast, which was

also removed by Professor Carmalt some two years before.

The results embodied in these plates, with the brief

appended description, may be said to be the results of some-

thing more than a year’s study into the microscopical appear-

ances of the carcinomata. Sarcomatous tissues have also

come in for their share of study, with results that, while of

great interest, are as yet too imperfect to warrant a considera-

tion of them at this time, even if space permitted.

As to the ‘‘cancer bodies,” or enclosures, the writer simply

presents them as evidence corroborative of the results obtained

by other pathologists. As will be noted, they correspond,

except in minor details dependent in part upon a difference

in ‘‘technique” in preparation, to the bodies described by,

at least, Ruffer and Pio Foa. The results obtained by other

observers are strangely at variance, and, it must be admitted,

unexplainably so.

For a discussion, vo and con, as to the nature of these

bodies, it is sufficient to refer to Sajous’ Annual of the Unt-

versal Medical Sctences for 1895.

With regard to Cornil’s idea that they are simply invagi-

nated cells, it is hardly to be thought of when we refer to the

examples of this depicted in Plate I., Figs. 4, 5 and 6, and

Plate III., Fig. 24. Dr. Welch, of Johns Hopkins, in express-

ing the opinion* that they are fragments of eleidin or kerato-

hyalin, or other products of protoplasmic degeneration, is

probably in error. If such were the case, fragments of elei-

din or kerato-hyalin, under similar treatment, would present

the same appearances zz normal tissues, and the same may

be said regarding other explanations that have from time to

time been offered.

A process of endogenous cell formation has been suggested

as explanatory of these appearances; but here again comes

in ‘‘control sections” of other instances of exceedingly rapid

cell proliferation, such as granulation tissue and certain forms

* Quoted by Dr. Ruffer, Jour, Path and Bact., 1893.

THE CELLULAR PATHOLOGY OF CARCINOMA. 259

of rapidly growing adenomata. Such appearances, arising

from endogenous cell formation, or any other method of cell

formation are not, and, so far as the writer's knowledge goes,

never have been demonstrated in these or other tissues.

Mastzellen, the so-called ‘‘feeding cells” of Altman,

have also been mentioned in this connection, for no other

reason that the writer can see than that certain of the Protozoa

in their early stages present the appearance of a simple mass

of granular protoplasm. These Mastzellen are very abund-

ant in certain rapidly growing tissues, as, for instance, in

young animals, such as the sheep, where they may be readily

demonstrated in the lung. They are also met with very

frequently in the human subject, and are particularly notice-

able in some sarcomata.*

Professor Klebs, in June, 1890, refers to these enclosures

as hyaline bodies, and is ‘‘decidedly disposed to regard them

as degenerative products” (Deutsche Medicinische Wochen-

schrift, Nos. 24, 25, 32, June, 1890). Without, however,

going into the discussion further, it may be said that the fore-

going sum up the most rational attempts at explanation of

these appearances, aside from those in which they are regarded

as Protozoa.

In so far as the writer's experience goes, these enclosures,

as above described, are peculiar to the carcinomata. Profes-

sor M. C. White states that he has met with one or more in

a section of apparently normal kidney. The writer, however,

had no opportunity of examining it. A. A. Kanthack says

(British Medical Journal, March 14, 1891,): ‘‘ These organ-

isms, whether we call them Protozoa, or psorospermiz, or

sporocysts, or what not, occur, and even frequently, in other

diseases, even in apparently healthy tissues.” Be this as it

may, the study by the writer of over a thousand sections of

various tissues has failed to show them in any other situa-

tion.

As totheir occurrence in a// carcinomata as much can not

be said. Some sections have failed to show them, but sec-

* See Plate I., Fig. 9.

260 CLIFFORD WALCOTT KELLOGG :

tions from another portion of the tumor, possibly, might have

done so. Inthe vast majority of instances, however, they

are to be found without great difficulty. They are more

abundant, seemingly, in soft, rapidly growing cancers, as for

instance, the encephaloid growth above referred to. They

are also more readily demonstrated, apparently, in secondary

growths, although this cannot be said to be invariable. They

cannot be said to be everywhere present, or, as a rule,

abundant. One may have quite a search without finding a

single enclosure, while again a solitary field may show half a

dozen or more. As has been said, they are almost invariably

econtained within the protoplasm of the cell. The writer has

never found one within the cell-nucleus, and in but one or

two instances have they appeared outside the cell.

A short time since, the writer was enabled, through the

courtesy of Dr. Charles J. Foote, to see the colored plates,

together with original paper, of Ruffer and Walker (Jour. of

Path. and Bact., 1893). Engravings, however, prepared from

these, appear in Green’s Pathology and Morbid Anatomy

(Seventh Am. Ed.).

Dr. Ruffer employed the ‘‘Ehrlich-Biondi” stain with

good effect, describing, however, an orange cell protoplasm

with a parasite (?) of ‘‘Cambridge” blue. Precisely his

effects the writer has been unable to obtain, but it is to be

noted that he embedded and cut in paraffin, while the draw-

ings that accompany this paper were from tissues cut in celloi-

din. Again, Dr. Ruffer describes the parasite as refractory

to hematoxylin, while Pio Foa (Annual Universal Medical

Sciences, 1894,) demonstrated his bodies most satisfactorily

by its use. The writer finds, with him, that they stain very

readily with ripe hematoxylin (Gage’s), but inasmuch as the

cell nuclei do thesame, it requires a practised eye to differen-

tiate them.

We have thus, in a necessarily brief and incomplete way,

studied some of the appearances that, as has been said, in a

measure tend to give color to the theory that cancer is

dependent upon the presence and growth of a specific organ-

THE CELLULAR PATHOLOGY OF CARCINOMA. 261

ism; and we have also considered, in part, the various expla-

nations that have from time to time been offered to account

for these appearances. Most, if not all, of these attempts at

explanation, however, are manifestly inadequate and by no

means cover the entire ground, and hence it is useless, in the

face of such amass of evidence as has accumulated, to attempt

to deny that the cells of carcinoma, in many cases, contain

structures that, if we can rely upon our present teach-

ings in the science of histology, are not an integral portion

of the tissues. At the same time, however, we are forced to

admit that evidence as to their precise nature is wholly and

entirely wanting. And this must be so, inasmuch as at

present we are dependent upon mere morphological appear-

ances for our knowledge, rather than upon biological detail,

and a knowledge of the life history of the organism, if organ-

ism it be. Artificial cultures have been attempted, but up to

the present time have not been successful. We are hence

compelled, as it were, to suspend judgment, bending our

energies meanwhile to the development of thorough and sys-

tematic methods of study, methods which involve the study

of the living, growing cancer, rather than that of simple

microscopic sections alone.

The fact has been befure referred to that Neisser (oc. cit.)

was among the first to regard these structures as Protozoa

(class Sporozoa, sub-class Coccidia). In this he is supported

by nearly all of the recent observers, including that most accu-

rate of zoologists, Metchnikoff. Even the great Billroth

inclines to the same belief (op. czt.). He was apparently

much impressed by the investigations of Bollinger and J.

Pfeiffer into the etiology and pathogenesis of the infectious

epithelioma of birds; they stating as follows: ‘‘ The epitheli-

oma formation is brought about by the immigration of the

germs of a Protozoon of the class of the Sporozoa (Gregarine)

into the cells of the rete malpighii. Whilst the cells affected

by the parasite are entirely consumed up to a narrow border

line, and the nucleus pressed against the cell wall, a prolifera-

tion of the still intact epithelial cells in the neighborhood of

262 CLIFFORD WALCOTT KELLOGG:

the invaded region takes place, the progeny of which are

successfully invaded by the parasite.”

The simple comparison of this description with some of

the appearances in the accompanying drawings™* in itself fur-

nishes some food for thought.

For the best brief exposition of the life history of the Pro-

tozoa themselves, the reader, perhaps, had better refer to

Lankester’s article in the Eucyclopedia Brittanica. A few

words, however, based upon his terminology may perhaps

be offered as a fitting conclusion to this paper.

‘« Protozoa,” as is well known, is the name applied to the

lowest grade of the animal kingdom, being sharply and defi-

nitely distinguished from the higher groups of Metazoa and

Enterozoa by the fact that they are structurally single cells

or units of protoplasm ; whereas the latter consist of aggre-

gations of such units, which are embryonically arranged into

two, or in the highest types, three layers. While, however,

the Protozoa are essentially unicellular organisms, this is by

no means always the case ; as many consist of aggregations of

such cells with, however, this marked and peculiar distinction,

there is no differentiation into embryonic layers, and each

component cell is capable at any time of taking up and main-

taining an zudependent existence, the cohesion between the

cells having no economic significance.

As distinguishing the Protozoa from the lower grades of

plant life—the Fungi and Algze—we have the one great

feature that marks plant life as distinguished from animal life

in the higher orders; the plants are synthetical, capable of

elaborating their nourishment from the simplest compounds,

as carbonic acid and ammonia, while the Protozoa, like other

animals, require the preformed, higher organic compounds

for their nutrition. (The somewhat anomalous position of

some of the Fungi it is unnecessary to discuss here.)

The Protozoon individual, then, is a simple mass of proto-

plasm, varing in diameter from ,4, of an inch up to an inch

(as witness the gigantic Mummulites). In common with

*Plates II. and III.

THE CELLULAR PATHOLOGY OF CARCINOMA. 263

other forms of animal life, they are endowed with the power

of motion, possess a certain irritability, and are capable of

growth and reproduction. Perhaps not their least important

characteristic, when considered in connection with cancer, is

that of ‘‘ producing by chemical processes that take place in

their substance (over and above those merely related to nutri-

tion) a variety of distinct chemical compounds, which may

form a deposit in or beyond the superficial protoplasm of the

Fic. 28.

Renal cell, from Helix hortensts, containing full grown Gregarine,

Klossia helicina, (copied from Lankester). Compare with Figs. 16, 17, 18 and

26. MV. Cell nucleus. J. Body, nature unknown. &. Nucleus of AZossza.

corpuscle, or may accumulate centrally.” It will be noted

that there is every possibility of these chemical products pro-

ducing analogous effects to the so-called ‘‘toxines” of the

pathogenic bacteria.

As to modes of growth and reproduction, the Protozoon

follows the same course as tissue cells in general. While

simple binary division is thé rule, it is very usual that under

given conditions the Protozoon breaks up rapidly in from ten

to a hundred little pieces, each of which leads an independent

life and grows to the form and size of its parent. This is

shown in Fig. 28, where the Protozoon has gone on to the

264 CLIFFORD WALCOTT KELLOGG :

formation of a cyst, the contents of which break up into a

number of chlamydospores (coated spores). The analogy to

Figs. 15 and 23 is very striking.

A discussion as to the part played by various Protozoa in

the life drama of both vertebrates and invertebrates, while of

exceeding interest, is impossible at this time. As is well

known, they are intimately associated in the human family

with Paget’s disease of the nipple, with the so-called Kera-

tosts follicularis,” and with Molluscum contagiosum.” The

often quoted Cocczdium oviforme, that so frequently occurs

in the liver of the rabbit, particularly of those that inhabit

marshy districts, not infrequently gains access to and excites

inflammatory processes in the human liver. The so-called

‘‘Rainey’s tubes,” or ‘‘sacs of Meischer,” that occur in the

striated muscle fibers of the hog (Sus scrofa), are simply the

chlamydospore cysts of a Protozoon, in the majority of cases

being filled with falciform young. The epithelioma of birds

we have already referred to. Finally, as we pass down the

animal scale, the gills of the fresh water perch, the common

earth-worm, the garden snail and the familiar cockroach

(Llatta ortentalis) are all of them fertile fields for the demon-

stration of Protozoa.

These instances, together with innumerable others that

might be cited, simply show the extent to which these lowly

organisms participate in pathological as well as apparently

non-pathological processes occurring in the various types of

animal life.

In concluding, the writer once more begs to call atten-

tion to the fact that the foregoing demonstration of the

cell-enclosures of cancer simply corroborates the results

obtained by a number of pathologists during the past hemi-

decade. Inno sense do they furnish indubitable evidence

that the disease is dependent upon the presence of a parasite.

Neither can there be said to exist even proof positive that

these bodies are Protozoa. The resemblance, however,

of the anatomical details here presented, to those that illus-

trate the various phases in the life history of certain of these

THE CELLULAR PATHOLOGY OF CARCINOMA. 265

organisms, is certainly very striking. Still, the evidence is

far from complete, and for the present we are simply justified

in considering the whole matter as sub judice. In the face,

however, of the facts presented, we can certainly do no less

than admit that the cells of carcinoma, in very many instances,

present appearances that are wholly and entirely unexplain-

able by any reasoning based upon our present knowledge of

pathological histology.

The writer wishes, in closing, to acknowledge his great

indebtedness to Dr. M. C. White, Professor of Pathology in

Yale University, for the advice and assistance so kindly and

courteously given. ;

266 THE CELLULAR PATHOLOGY OF CARCINOMA.

PLATE I.

Fig. 1. Cancer cells.

m. Nuclei.

s. Small round cells.

Fig. 2. Cancer cell.

Nucleus dividing.

Fig. 3. Cancer cell.

Two nuclei.

Fig. 4. Cancer cells.

Invaginated. 2. Nuclei.

Fig. 5. Cancer cells.

Invaginated.

Fig 6. Cancer cells.

Division after invagination.

Fig. 7. Cancer cell.

Hydrophic degeneration about nucleus (7).

Fig. &. Cancer cells.

Invaginated cell; nucleus broken up.

Fig.9. Mast Zellen. (Methyl-blue.)

Zeiss. Objective, #y. Oil immersion. Ocular, 4. C. W.K., Pinx.

Plate |.

Fig 3

Bis.

Fig 6.

Figs

Fis 4.

Fig 9

Fis: 7.

268 THE CELLULAR PATHOLOGY OF CARCINOMA.

Fig. 10.

Fig. 11.

Fig. 12.

PLATE II.

Cancer body or enclosure.

From scirrhus of breast.

2. Nucleus.

Cancer body or enclosure.

(From another case.)

Two cancer bodies in one cell.

(From scirrhus.)

Three cancer bodies.

(From scirrhus of breast.)

Five cancer bodies involving two cells.

From encephaloid of cerebellum.

v. Vacuole.

A crowd of cancer bodies.

From same specimen as Fig. 14.

Different type of enclosure.

From encephaloid.

Different type of enclosure.

From same growth as in Fig. 16.

Two enclosures involving two cells.

From same growth as in Figs. 16 and 17.

Objective, 75. Oil immersion. Ocular, 4.

C. W. KeePinxe

\ ou Me) a)

‘ON ee on

le - fc

= :

£ * | i

a = ic

pal

=) ) a

on pe ©

Hie i =

pan oe a” be Des -_ am —- a4

270 THE CELLULAR PATHOLOGY OF CARCINOMA.

PLATE Ill.

Fig. 19. Two cells.

(From scirrhus of breast.)

Fig. 20. One field.

(From scirrhus. )

Fig. 21. Two cells.

(From scirrhus.)

2 = Fragment of nucleus.

Fig. 22. Single cancer alveolus, showing three enclosures.

Fig. 23. Single cell.

Nucleus has disappeared.

(From secondary cancer of liver.)

Fig. 24. One field.

Enclosures and invaginated-cell.

Fig. 25. Apparent division.

Nucleus displaced.

Fig. 26. One field.

(From encephaloid.)

Fig. 27. Fuchsin bodies. (Russell.)

Fuchsin and iodine. (Green.)

Zeiss. Objective, #5. Oilimmersion. Ocular, 4. C. W. K., Pinx.

Plate Il.

OS ee ee

Fig 21.

Fis 20.

Fig 19.

é 23.

Fié 26.

Fig 25

DIPHTHERIA—ITS BACTERIOLOGY.

CHARLES F. CRAIG, M. D., Danspury, Conn.

HISTORICAL.

The history of the discovery of bacteria in this disease is

one full of interest. In 1868, Oertel found micrococci present

in the false membranes, and in investigations made in 1874 he

found the Bacterium termo present. He was even successful

in producing croup experimentally in animals, and stated his

belief to be that these micrococci were the cause of the disease.

Nasililof, Hueter and Tommasi also found micrococci present

in this disease, and Klebs, tn 1871, and Eberth, in 1872,

claimed that the diphtheria micrococci were identical with

those of sepsis. At this time the theory of the microbic

origin of this disease seemed well founded, but it had many

enemies, among the most prominent of whom were Senator

and Billroth.

In 1877, Drs. Curtis and Satterthwaite were selected by

the New York City Board of Health to investigate the cause

of this disease, and as the result of their investigations they

reached the conclusion that the so-called diphtheria micrococci

were not essential in the production of the disease, and Drs.

Wood and Formad, who conducted a series of investigations

for the National Board of Health, arrived at the same con-

clusions. It was thus that the question stood when, in

1883, Klebs first called attention to a bacillus which he found

upon the false membranes, which he cultivated, and in 1884

Loffler published his investigations upon the same organ-

ism. He was able to separate and cultivate it, and, though

not at that time able to produce the typical disease in animals

by inoculation, he showed that the organism was poisonous.

272 CHARLES F. CRAIG:

His observations were confirmed by Frankel, and Roux was

shortly after successful in producing the disease in animals by

using cultures of the bacillus. The organism became known

as the Klebs-Loffler bacillus, and is now generally recog-

nised as the cause of diphtheria.

Very valuable contributions to our knowledge of this

organism have been made by various observers, among the

more recent being those of Kolisko and Paltauf, of Vienna ;

Ortman, of Konigsberg; Escherich, in Munich; Bech, Brieger,

Frankel and Behring, of Berlin ; Babes, in Bucharest ; Klein,

of London ; Roux and Yersin, of Paris ; and Welch, Abbott,

Prudden, Park, Councilman and others, of this country.

DESCRIPTION.

The Klebs-Loffler bacilli are short rods, straight, or

slightly bent, about as long as the tubercle bacillus, but

much thicker, and presenting a plump appearance. The ends

of the rods are rounded. These bacilli vary greatly in size

and appearance under different modes of cultivation, some-

times appearing to be enclosed within a capsule, either as a

straight rod or transversely segmented, or oval or elliptical

in shape, with swollen ends. Very often, either at the ends

or the middle of the bacilli, small round portions, more

deeply stained than the remainder of the bacilli are seen,

which by some authorities are regarded as spores, but spore

formation has not as yet been proved. They are non-motile.

In microscopic slides made from portions of false membrane,

the bacilli appear in patches and clumps, and also scattered

singly over the field examined. The bacilli are found only

upon the false membranes and the mucous membranes of the

air-passages. They are very resistant, and have been found

to be virulent in dried membrane after four weeks. Roux

and Yersin found that serum cultures were virulent, under

ordinary conditions, after five months, and if protected from

heat and light after thirteen months.

Regarding the persistence of the bacilli in the throat dur-

ing and after recovery from the disease, Park, the inspector

DIPHTHERIA—ITS BACTERIOLOGY. 273

of diphtheria for New York City, reports that of 752 cases

examined, 325 were free of bacilli in the throat three days

after the disappearance of the membrane, 201 after from five

to seven days, 84 after twelve days, 69 after fifteen days, 57

after three weeks, I1 after four weeks, and 5 after five weeks.

In one case the bacilli were found after seven weeks, and not

only present but virulent.

He also found in healthy persons exposed to the dis-

ease, where isolation was not practised, virulent bacilli in 50

+ 1,200 and enlarged threefold.

per cent. of the cases examined, forty-five in number, and

iat, of these, 40 per cent. later developed the disease.

Where isolation was carefully attended to, virulent bacilli

were found in only 11 per cent. of the cases examined of

healthy persons exposed to the disease.

Park and Beebe examined the throats of some 330 persons

in New York City, who, as faras known, had not been exposed

to diphtheria, and found virulent bacilli present in eight cases.

Park has cultivated virulent bacilli from dried stains on

spreads and bed linen, where diphtheritic patients had expec-

274 CHARLES) Fr (GRAIG:

torated, and has also shown that the sputum of patients, even

after being free from bits of membrane, contains great num-

bers of the bacilli. Wright and Emerson have obtained

virulent cultures from the hair, finger nails, shoes and cloth-

ing of nurses to diphtheria patients, and also from chairs,

brooms and other objects in the diphtheria ward of the

Boston City Hospital, and also in dust collected from the

same ward. Williams, of Boston, has found that 50 volume

solution of hydrogen dioxide will kill the diphtheria bacillus

in five seconds in the laboratory, and recommends it in the

treatment, locally, of the disease. A solution of 1-4000

bichloride of mercury is much thought of by Park in the local

treatment of the disease. The bacilli perish at a temperature

betweenpa5 "to 507 € r(112"to122 iy)

STAINING.

These bacilli do not stain by Gram’s method, nor well by

the ordinary aniline dye solutions. They stain best by the

following method. Make up the following staining solution :

ANicoholtsol-gmethyl-bluerrm rast -mcr (wees s 00 aren BO'GuC:

©:01 per cent. sol-.caustic) potash = <2). ye) os 100 ¢. C.

(1 part caustic potash in 10.000 of water.)

Stain the specimens in this for ten minutes, and then place

them for fifteen seconds in a } per. cent. acetic acid solution.

Wash in absolute alcohol and mount in balsam. The bacilli

will be stained a dark-blue color.

Crouch, of Denver, in an article recently published,* states

that he believes that a direct cover-glass diagnosis of this

organism can be generally secured by attention to certain

peculiarities in the behavior of this bacillus to certain stains.

He found that if a cover-glass prepared as usual, froma blood

serum culture, about twenty-four hours old, be treated a few

seconds only with methyl-green, in 1 per cent. solution, the

following appearances were noticed: ‘‘ The majority of the

bacilli will be stained faintly green and contain at both ends

a well-defined round body much more deeply stained, and of

a distinctly red color.”

* New York Medical Journal, October 5, 1895, page 430.

DIPHTHERIA—ITS BACTERIOLOGY. 2

unr

He found the following fluid most serviceable :

I per cent. sol. methyl-green (freshly prepared). . a 5 parts:

I per cent. sol. dahlia (freshly prepared). ..... . : I part.

Pistiblediwater 7.) hs) 2. SS. Uk het sate eee 4 parts.

He states that only a second is required for staining—stain-

ing being too intense after a longer time. He further says:

‘‘ By smearing a piece of the membrane on the cover-glass,

drying and flaming in the usual way, and staining (with the

above solution) one or two seconds, the diphtheria bacilli, or

certain of them, will present the appearances described above.

Wherever I have found such forms, even if only two or three,

in the direct cover-glass examination, the cultures have

developed diphtheria bacilli without one exception, so that I

have come to regard this reaction as of the greatest diagnos-

tic importance.”

CULTURE.

These bacilli are facultative anerobic, growing best between

60° and 104° F. They grow on gelatine, potato and other

media, but the media must be slightly alkaline in reaction.

Kolisko and Paltauf found that growth takes place readily

upon nutrient bouillon containing sugar. Loffler obtained

the best results upon the following media :

Bigodssenumay(Cattle) iiss: 01 isco we Nees pects Cale. Wer om mone 3 parts.

Beet DOUUION rn fmt) Seis cls 4G Geter area eee ee eae I part.

eC PLONC Meg sr chle) seeks cil's Lat oath iyd 1 beeen paca eee I per cent.

COmMOntsaliimeeetedey cows ie Cok kre ken: at nee ee ¥% per cent.

GREYS CULE Sie oat Aen ineo ne Guten ed Geers 8! che I per cent.

They also grow especially well upon glycerineagar. Cul-

tures on this media are dull white in color, flat, and present

a glistening appearance, with smooth edges and about the

size of a millet seed. They develop in from twenty-four to

forty-eight hours. Welch and Abbott have found that the

bacillus can be cultivated upon potato. Thrust cultures in

gelatine are composed of white globular. colonies, which

develop along the line of puncture.

In some of the large cities of this country the resident

board of health makes cultural examinations of suspected cases,

276 CHARLES F. CRAIG:

for the convenience of physicians, and the methods employed

being of interest, I therefore quote largely from a paper by

Park,* the inspector of diphtheria in New York City, regard-

ing the manner of collection and examination of the speci-

mens. The methods described can be carried out well by

the general practitioner, where there are no laboratory facili-

ties. Following are quotations from his papers:

‘* Technique of Preparing the Serum Tubes and the Swabs.

—The blood is received directly from the slaughtered sheep

or calf into large, thoroughly cleansed preserve jars, and

covered. These jars are putas soon as possible on the ice.

After a few hours the jars should be inspected, and if the clot

is found adhering to the sides it should be separated. After

twenty-four hours on the ice, the serum is poured off and

mixed with one-third its quantity of nutrient bouillon, to

which 1 per cent. glucose has been added. This is poured

into test tubes, which should be about five inches in length

and filled one quarter full. They are placed very obliquely

in the serum coagulator, and kept just below 100° C. for one

hour on twoconsecutive days The tubes with the sterile

solidified blood serum can then be placed in covered tin

boxes and kept for months. The serum prepared in this way

is quite opaque, but its value is not lessened for the purpose

for which it is intended.

‘« The Swab.—A stiff piece of wire, or, better, a thin

steel rod, six inches in length, is roughened at one end by a

few blows of ahammer. About this a little absorbent cotton

is firmly wound. A number of these are placed in an equal

number of glass tubes, the ends of which are plugged with

cotton. They are sterilised by dry heat at about 150° C. for

one hour, and stored for future use.

‘‘For convenience in carrying the tube containing the

blood serum and the tube containing the swab, they are

wrapped in a little cotton and placed in a cheap, strong pen-

cil box.

* Diphtheria and other Pseudo-Membranous Inflammations. Medical Regord, February

II, 1893.

DIPHTHERIA—ITS BACTERIOLOGY. 277.

‘« Directions for the Physician to Use in Inoculating the

Tubes with the Exudate.—The patient should first be placed

in the best available light, and if a child, properly held.

Taking the swab from its tube, the tongue is depressed, and

the side of the swab is rubbed firmly against any visible mem-

brane, thus catching little particles in its meshes. Without

laying it down, it is inserted the full length of the blood

serum tube, and the part of the swab which was previously

rubbed against the throat is drawn rather firmly along the

full length of the serum surface. ‘It is then re-inserted in its

own tube for future use in making control cultures.

‘« A second culture on a blood serum tube is made from the

swab (at the laboratory office). Both serum tubes are placed

in an incubator at 37° C. for twelve hours. They are then

ready for examination. On inspection the blood serum sur-

face will be seen to be dotted with very numerous, just visi-

ble, translucent colonies. At this time no diagnosis can be

made by simple inspection. He then takes a clean cover-

glass and with a platinum loop makes a sweep over a major-

ity of the colonies, and smears upon the cover-glass, staining

with the Loffler methyl-blue, as described under Stazuing.

There will then be seen either a large number of characteris-

tic diphtheria bacilli, with a small number of diplo- or strep-

tococci, or a more equal distribution of the true bacilli and

the other cocci, or else, where diphtheria is not present, a

pure culture of diplococci or streptococci.”

Regarding the diagnostic value of this method, he says:

‘« A very extended trial has convinced me that cultures on

blood serum, made immediately from the. fresh exudate on

sterile swabs, can be thoroughly relied upon to show a growth

of Loffler bacilli, when these were present and living in the

throat at the time of the swabbing, whether visible membrane

existed or not.”

The method above described can be carried out by the

general practitioner, and as a reliable diagnosis of diphtheria

is many times of inestimable value in protecting other lives,

it should be done where access can not be had to a bacterio-

278 CHARLES F. CRAIG:

logical laboratory, and where doubt exists as to the nature of

a given case. The general practitioner should be some-

thing of a bacteriologist, for many lives often depend upon

his diagnosis of just these cases.

EXPERIMENTAL.

Inoculations in animals of cultures are not always followed

by success, rabbits, guinea-pigs, chickens and doves being

very susceptible, rats and mice not very much so. In the

susceptible animals, false membrane is formed in the trachea

and sometimes there are constitutional symptoms. Guinea-

pigs are very susceptible, and die in a few days after inocula-

tion.

Babes, in a series of experiments, irritated slightly the

conjunctive of rabbits and then placed upon them pure cul-

tures of the bacillus. The rabbits died in a short time after-

ward.

Brieger and Frankel have succeeded in separating a tox-

albumin from cultures of the bacilli, which when injected pro-

duces albuminuria and paralysis.

IMMUNITY.

Frankel, Brieger, Kitasato, Behring, Roux and other

observers have studied the problem of producing immunity

to this disease in animals. Behring and Kitasato have done

so by making use of sterilised cultures, by adding iodoform

to cultures, and in various other ways, and they found that

animals rendered immune are not only safe from the living

diphtheria bacilli, but also from the products of their metabol-

ism. Frankel also obtained immunity by using sterilised

cultures.

ANTITOXIN OF DIPHTHERIA.

Of great practical interest is the question of the treatment

of this disease by its so-called antitoxin. The principle

involved is that the blood serum of an animal rendered

immune to the disease, is possessed of curative power when

injected into a patient suffering from the disease, by virtue of

DIPHTHERTA——ItS BACTERIOLOGY. 279

an antitoxic substance which has been elaborated. The

method of preparing the antitoxin depends upon continuously

and progressively injecting a very powerful toxin into an

animal ordinarily non-susceptible (the horse is used), and

thus the production in this animal’s blood of the antitoxin.

The antitoxin is in the serum only of the blood.

In 1888, Roux and Yersin discovered and isolated the

diphtheria toxine, and to Behring, of Berlin, belongs the credit

of the great discovery that the blood of an animal immunised

to this disease may be used in treating the disease in the

human subject. His observations were published in 1894,

and since that time the treatment has been followed out ina

great number of cases, both abroad and in this country. In

the Berliner Klinische Wochenschrift, 1894, No. 36, Behring

thus sums up the blood serum therapeutic method:

‘*1, It isan antitoxic method by which we endeavor to

combat those infectious diseases which we know to be of

micro-parasitic origin. These include the infectious diseases

and certain vegetable and animal poisons (as snake poison).

The specific antitoxins, which are the active agents, have

until now been found in quantities sufficient to be available

for human medication only in the blood of immunised

animals.

2, itis a principle of the bleod serum therapy, that

larger doses are never injurious, but, on the contrary, can be

only beneficial.

‘¢3. The blood serum therapy isa specific therapy. Each

blood antitoxin is immunising and curative only for one infec-

tion.

‘‘4. Under the influence of a specific toxin there is pro-

duced a specific antitoxin from the albumin of the living cell.

Whilst this is going on there is a disturbance of the regulat-

ing mechanism of the general organism. The febrile and

other symptoms of a toxic infection are an expression of the

effort of the living organism to render the foreign poison

innocuous. In animal experiments we can so arrange things

that the living organism succeeds. In immunising animals

280 CHARLES F: CRAIG:

we render the absorption of even larger quantities of the

poison harmless by increasing the antitoxin production. |

‘¢c. If we examine the bodily fluids after recovery from

an artificial or natural toxic infection, we find not only that

the toxin is compensated by the antitoxin, but that thereis a

surplus of the latter. This surplus is the reason why a larger

quanity of the toxin must now be introduced in order to pro-

duce intoxication. And this surplus can be employed to

help other individuals to overcome the same intoxication.

The entire blood serum therapy rests on this fact.

‘©6, Since these antitoxins are soluble chemical bodies,

it is not impossible that they may eventually be produced

outside the living body, or even compounded syntheti-

cally.”

This treatment, as applied to diphtheria, has been elabo-

rated by Aronson, Roux and Yersin, and others, and today

stands preéminent as a life-saving measure inthis disease. It

has received the endorsement of such eminent clinicians as

Baginsky, Virchow, Ganghofer, Sonnenberg, Kolisko, Bokai,

Moisard, Fischer, Welch, Park, and many others, and

should always be tried along with the older methods of com-

bating the disease. In 9,487 cases, tabulated from reports in

the Medical News, 1894-95, and Bulletin of Johns Hopkins

Hospital, July-August, 1895, the death-rate is 16.5 per cent.

where antitoxin serum was used, while by the old methods

alone the death-rate was 47.5 per cent. In the Deutsche

Med. Wochenschrift (1895, No. 32,) is published a collective

investigation of cases treated both with and without the anti-

toxic serum. In Berlin, of 562 cases treated by serum, 84

died, or 15.1 per cent. ; of 282 cases treated without the

serum 49 died, or 17.4 per cent. Outside of Berlin, of 5,271

cases treated with the serum 9 per cent. died; and of 4,197

cases treated without the serum 14.4 per cent. died, Totals,

5,833 with serum, 9.6 per cent. died ; 4,479 without serum,

14.7 per cent. died. From the foregoing reports, it will be

seen that the mortality in this dread disease has been reduced

nearly or quite one-half.

DIPHTHERIA—Its) BACTERIOLOGY. 281

A few cases have been reported in which death has been

blamed upon the serum, but this is not by any means proven

to have been at fault, and considering the immense number

of injections which have been made with nothing but favor-

able results, these cases must be of doubtful nature.

THE PSEUDO-DIPHTHERITIC BACILLUS.

Hoffman, Frankel, Escherich, Loffler and others have

described a bacillus occurring in cases of membranous angina,

differing but slightly from the Klebs-Loffler bacillus, some

observers even claiming that it cannot be differentiated.

They are somewhat shorter and thicker, grow at a tempera-

ture of 20-24° C. (68° to 72° F.), forming a mere yellow

layer upon agar, and changing the reaction of bouillon less

rapidly. They do not grow as well inthe presence of oxygen

as do the true bacilli. Inoculations into animals sometimes

produce local manifestations, but never death.

Hoffman found them frequently in the heaithy pharynx ;

Frankel, Roux and Yersin think that they are the same

bacilli as the Klebs-Loffler, which have in some way lost

their virulence. Welch thinks that the name pseudo-diph-

theria bacillus should be applied only to bacilli which, though

resembling the Klebs-Loffler bacillus, differ from it in being

non-virulent, growing more luxuriantly on agar, and the pre-

servation of the alkaline reaction of the bouillon cultures.

He holds it to be of a different species than the diphtheria

bacillus, and considers it of no diagnostic importance. Pal-

tauf, Sevestre, Baginsky, Martin, Park and Prudden have

described cases of membranous disease where the Klebs-

Loffler bacillus was absent and only streptococci could be

demonstrated. Staphylococci are often found within the

false membrane, but they bear no relation to the disease.

For clinical purposes, all cases which give bacilli resembling

the Klebs-Loffler bacillus in culture and under the microscope

should be considered diphtheria.

THE BRAIN OF THE EMBRYO SOFT-SHELLED

TURTLE.

SUSANNA PHELPS GAGE, Ph. B., IrHaca, N.Y

In a paper read before the Microscopical Society last year,

upon the ‘‘ Comparative Morphology of the Brain of the Soft-

shelled Turtle (Amyda mutica) and the English Sparrow

(Passer domesticus*),” certain questions were raised, which

could only be answered by studying the development in the

soft-shelled turtle, as: When and how do the characteristic

features of the brain in this group of turtles arise? When

and how do those features arise which distinguish them from

birds?

Professor Eigenmann, who was present, kindly sent me six

embryos of Asfidinectes, a closely allied genus of the turtle,

in different stages of development. Serial sections were

made of the heads and mesal views reconstructed. A brief

summary ofthe result obtained is given below. Fuller state-

ment, with illustration, is reserved until more material is

studied.

The body of the youngest specimen was 7 mm. long;

the form generalised; the face short; the diameter of

the eye, one-half the lengthof the head. A narrow carapace

was distinguishable ina specimen, with length of body II mm.

In the oldest specimen the carapace was I6x1I mm., and

had the characteristic leathery appearance and markings of

the adult. The snout had also the elongated form of the

adult. The feet were webbed. The diameter of the eye,

though twice as great as in the youngest specimen, was only

one-third the length of the head.

* TRANSACTIONS Ainerican Microscopical Society, Vol. XVII., 1895, pp. 185-238, 5 plates.

BRAIN OF THE EMBRYO SOFT-SHELLED TURTLE. 283

1. As seen from the meson, the most striking difference

between the early and late forms of the brain is the general

shape. Taking as reference points the center of the geminum,

the union of the myel with the oblongata, and the tip of the

olfactory lobe, in the youngest embryo the figure formed is

an isosceles triangle, in the succeeding stages changing to a

flattened triangle by the elongation of the base. The cephalic

limb of the triangle increases greatly, while the folding of the

caudal part of the brain produces an actual shortening of the

caudal limb of the triangle. Inthe adult Amyda, the flat-

tening of the triangle has proceeded to an extreme. The

change of form in the brain is apparently greater between

the time when the external appearance of the adult is estab-

lished, as in the oldest embryo, and the true adult condition,

than between the oldest and youngest of the above-described

embryos. This is due to the fact that after the external adult

appearance is complete the cerebrum and the cerebellum

both acquire their largest comparative growth.

2. At the constriction occurring in the brain-tube,

between the postcommissure and the floor of the cranial flex-

ure, the brain shows the least increase in size, as shown by

different measurements upon the meson, of the embryo and

adult brain. This stationary condition is probably due to

the early maturing of the region.

3. The union of the olfactory lobes across the meson was

not found in these turtles until the beginning of the carapace

was distinguishable, and did not present the comparative

extent and close connection of the adult until the oldest

embryo with the adult appearance. That is, as was found

with the sparrow, the union across the meson is of late

occurrence and secondary importance.

4. Those parts of the cerebrum, apparently connected

with olfaction, the hippocampal, progress with equal step

with the olfactory lobe, and not until the oldest embryo is

the fimbrial edge of the hippocamp and its union across the

meson, the fornicommissure, well established. The late

appearance of this commissure is consonant with great varia-

284 SUSANNA PHELPS GAGE:

tion in different types, but this study tends to corroborate

the opinion now gaining ground, that this commissure in the

lower vertebrates is not a callosum.

5. That part of the cerebrum so prominent in the adult,

the caudatum, or elevated portion of the striatum, is only

found as a rather inconspicuous object in the oldest embryo,

but the precommissure, in which fibers from the upper parts

of the striatum cross, arises as the carapace begins to form.

6. In the roof of the brain the postcommissure is a well-

formed landmark in the earliest of the embryos, while the

commissure, bounding the opening of the epiphysis, the

supracommissure, shows as a mere trace in the youngest

embryo and attains a disproportionate development in the

oldest. A similar culmination in growth is seen in the oldest

embryo in the associated epiphysis, habenz and the fiber

tract extending from this region to the cerebrum, a fact

apparently indicating that in ancestors of this group having

comparatively simple brains these parts were of more import-

ance, for in the adult turtle they are overshadowed .by the

later developing parts.

7. The membranous roof in all embryos is a simple

unfolded membrane, clearly continuous with the paraplexuses

of the cerebrum. The latter, in the early stages, are simple

membranes, which show folds only when the carapace begins

to develop, and become quite complex in the oldest embryo.

The paraphysis, at the point of union of the diaplexus with the

paraplexuses, is a widely open tube in all the stages, and

becomes early convoluted.

8. The medicommissure, a feature which is found in

mammals and reptiles, but not in birds, arises in this turtle

only in the oldest embryo, in this being like mammals, in

which it also appears late, and showing that though charac-

teristic, it is of secondary importance.

g. In theinfundibular region of the embryo are seen dis-

tinct folds and pits, which are nearly obliterated in the adult.

A pair of protuberances, dorsad of the hypophysis, occurs in

the younger forms, and is represented in the adult by a single

BRAIN OF THE EMBRYO SOFT-SHELLED TURTLE. 285

mesal notch. Dorsad’‘of these, a mesal protuberance, lying

between two commissures, is much more prominent in the

younger specimens before the commissures are formed. The

decision upon homologies of these protrusions of the wall

with either the albicans of the higher forms or the hypoaria

of fishes must be reserved, for there are details of difference

with both.

10. In the turtle, all parts connected with vision are well

developed. In the youngest embryo the optic recess is

clearly traceable to the eye along the optic nerve, as the

remains of the originally open vesicle. This remnant becomes

more convoluted, the endymal cells giving an almost glandu-

lar appearance, in the stages when the carapace begins to

develop. In the oldest embryo this appearance is gone, but

the numerous cells of the chiasma in the adult may repre-

sent this convoluted vesicular remnant.

11. The optic geminum does not lose the form of a thin-

roofed single vesicle until in the oldest embryo a mesal

depression occurs, forming the paired geminums, and at the

same time an extensive union across the meson by means

of the geminal commissure, and a division of the cells into

two layers arise. The late formation of this solid roof of the

geminums is interesting in connection with the fact that in

birds the roof remains a membrane.

12. In the latest embryo the cerebellum is only just

beginning its growth as a great mesal feature, though consid-

erably earlier it is apparent asalateralorgan. In the young-

est embryo its appearance is like that of the Amphzdza,

having a small mesal portion. With its growth caudad it

revolves, so to speak, about a fixed point, carrying the thin

membranous wall before it, and thus forms the folded meta-

plexus of the adult. The oldest embryo shows this admir-

ably.

13. The floor of the oblongata undergoes wonderful

changes, from a comparatively thin-walled condition in the

youngest embryo, through one in which series of rounded

thickenings occur, these in turn becoming united, as the car-

286 BRAIN OF THE EMBRYO SOFT-SHELLED TURTLE.

apace develops, to form the continuous thickened floor of the

oldest embryo.

From the above it is seen that partial answers to the ques-

tions mentioned are now possible.

(a.) The general form of the brain of the soft-shelled

turtle wherein it differs markedly from the other described

turtles is only acquired after the embryo has the external

appearance of the adult, the great relative growth of the cere-

brum and cerebellum taking place after that period. (Sec.

id 324)

(2.) The union of the olfactory lobes across the meson

and the large caudal growth of the cerebellum seem to be

characteristic of this group of turtles, and it was found that

both are of late development. (Sec. 3, 12.)

(c.) The broad distinctions between the bird and reptile

brain are, that the latter possesses a medicommissure and a

solid roof to the geminums ; in the soft-shelled turtle both of

these features arise in the late embryo.

That is, in the brain not only those features which dis-

tinguish the group of turtles, but which most evidently dis-

tinguish birds from reptiles, arise in this turtle about the time

the external form is characteristic of the genera. The brain,

however, lags somewhat behind the body in assuming charac-

teristic features.

Other questions arose as to the appearance of the nidi and

their relation to sulci, which cannot yet be answered conclu-

sively.

NOTES ON TECHNIQUE.

PIERRE A. FISH, D. Sc., CorneLty University, Iruaca, N. Y.

In many of the modern articles, the methods by which

certain pathological structures are demonstrated, if mentioned

at all, are frequently so meager in the description of import-

ant details as to be practically useless to many workers, unless

a certain amount of their time is devoted to experimentation.

A person, who has obtained fairly successful results with his

older methods, is loath to forsake them, especially if his first

few attempts with the new are failures. Each investigator

may have certain laboratory conveniences ; reagents of the

best quality and dyes that have been well tested, all of which

will enable him to obtain results much superior to his less

fortunate colleague. It is difficult, therefore, to work suc-

cessfully unless details are carefully attended to, and the

reasons for the various steps understood. The methods fol-

lowing have been well tested, and have been attended with

uniformly good results, which in some cases, it is believed,

would have ended in failure with the older methods.

FIXATION.

The fixation of pathological tissues, with strong alcohol for

histological study, is very commonly employed for the double

purpose of killing at once any microorganism that may be

present and at the same time to preserve the structure of the

part. With many tissues this caused a too rapid withdrawal

of the contained water or lymph, so that the specimen

becomes hard and gives unsatisfactory results when it comes

to the cutting process.

Some experiments with different reagents, upon known

pathological material, were of service in formulating a mix-

288 PIERRE A. FISH:

ture, which obviated the defects of strong alcohol when used

alone. This mixture, while quickly killing the bacteria, also

preserves most faithfully the histological structure. Various

solutions of formalin, including the undiluted, were employed,

and gave good results, particularly the presentation of the

bacteria, after the usualstaining methods. The tissues were

more or less swollen by the weaker solutions, in marked con-

trast to the contraction caused by alcohol. Various combi-

nations of formalin with alcohol were also tried, and that

which seemed to be most completely satisfactory for quick

penetration and convenience, bacteriologically and histologi-

cally, was as follows:

95) per, jcentvalcoholss ta) So -R ke Meh i eS 100 parts.

Commercial formalin (40 per cent. formic aldehyde) . Io parts.

Pieces of tissue, } centimeter square, are well fixed in

from twelve to twenty-four hours, after which it is well to

leave for a few hours in 95 per cent. alcohol before clarifying

for the paraffin bath. Specimens, transferred directly from

the fixing mixture, have been clarified in chloroform or cedar

oil, but it requires a longer time.

The addition of the formalin is advantageous, because in

away it brings about a state of equilibrium. The alcohol

alone shrinks the tissue, while on the other hand formalin

swells it, so that in this respect the one reacts against the

other.

ADHESION TO THE SLIDE.

After the infiltration and imbedding of the tissue in paraf-

fin, the question of the treatment of the sections is one of

some importance. Ifthey are to be carried through a series

of reagents in watch glasses, and not placed upon the slide

until they are mounted, the sections must necessarily be

rather thick, in order to withstand the manipulation. Very

much thinner sections, if adherent to the slide, and conse-

quently supported by it, can be carried through the different

steps of the process without injury, and show the structural

elements to much better advantage.

NOTES ON TECHNIQUE. 289

The albumen or collodion adhesive, usually employed for

this purpose, however, possesses the disadvantage of taking

the aniline colors used in bacteriology, sufficiently to disfigure

the preparations. If a clean slide be coated with a thin film

of glycerine and then rubbed very nearly dry with a cloth or

the hand, and a drop or two of 35 per cent. alcohol be placed

upon it, the section, if curled, will tend to flatten itself when

placed on the alcohol. If the slide now be placed in a

thermostat for a few hours, at a temperature near the melting

point of paraffin, the heat will cause any wrinkles or irregu-

larities of the section to disappear; the alcohol slowly

evaporates and when the slide is thoroughly dry the albumen

molecules of the tissue adhere quite firmly to the slide, as

noted by Gaule. After this the slide may be heated gently

over a flame until the paraffin begins to melt. If any mois-

ture remains the section will be quite likely to loosen during

the latter stages. Thick sections do not adhere so firmly as

thin ones. The slides may then be immersed in a jar of tur-

pentine or any solvent of paraffin and carried through the

various grades of alcohol to water.

A shorter method, in which there is as firm adhesion of

the section to the slide, is to bring the slide in contact with

aniline oil for a few minutes after the treatment with the tur-

pentine, absorbing the superfluous turpentine with filter

paper. The aniline oil is also removed by means of filter

paper. The section is then thoroughly washed in distilled

water which removes the oil, and the tissue is then stained

and washed in water. If aniline stains are used, a hurried

rinsing is sufficient. Drain or absorb the water and again

apply the aniline oil. Besides clearing the section the oil

tends to remove the aniline stain and care must be exercised

in not letting this process gotoo far. Displace the aniline oil

with xylol and mount in balsam. The color ought not to

fade if the aniline oil has been thoroughly removed.

With certain stains, or combinations of them, the aniline

oil may not succeed in preserving the sharp definition of the

color. Under such conditions the section, after staining,

290 NOTES ON TECHNIQUE.

may be treated directly with absolute alcohol to dehydrate

and remove any superfluous stain. Some aniline dyes are not

as soluble in absolute alcohol as in the weaker grades. Clear

in xylol and mount in balsam.

The use of aniline oil in the treatment of the sections will

be recognised as having been recommended by Weigert for

bacterial purposes. It likewise gives most excellent results

in ordinary histological work and is a saving of time and

material.

MOUNTING.

Many valuable specimens are ruined for the want of suf-

ficient precaution in the preparation of the balsam. In its

commercial state it contains many volatile principles and

traces of acids, which, in the course of time, act upon the

specimen and diminishes or entirely removes the color. All

this may be lessened, if the balsam be heated sufficiently to

drive off the volatile constituents, or more thoroughly obvi-

ated if a little potassium carbonate or mild alkali be added

to neutralise the acid just before the balsam is heated. When

the balsam becomes hard it can be broken into flakes and

stored. When wanted for use dissolve in xylol to the desired

consistency and filter through absorbent cotton. Specimens

stained with the Biondi-Ehrlich mixture (which fades so

easily) have at the end of a year shown no signs of losing

their pristine clearness.

SOME METHODS OF HISTOLOGIC TECHNIQUE.*

J. MELVIN LAMB, M. D., Wasuineton, D. C.

In carrying on original work and in obtaining good results

in the course in normal histology in the laboratory under

our charge, it has been a problem of considerable interest to

reduce to the smallest possible amount the time and energy

expended in the work of preparing material for teaching a

class averaging about sixty students. While it is impossi-

ble to lay down any fixed rule in work of this character

to be the guide of the student in making preparations

for the study of normal histology, we believe that by the

employment of simple methods which will meet the largest

number of requirements in preparing tissues for examination,

and recommending these to the student, we reap the greatest

benefit from the necessarily limited amount of time allotted

to such a course. While points specially alluded to in this

paper are not original entirely, but are the result of long

observation of the working laboratory courses of various

teachers, I am satisfied that quite a number insure accuracy

in work with the least possible expenditure of time and

attention.

The student is taught from the beginning the general

principles of post-mortem examination, cautioned as how to

be selective in material for normal and pathological histology,

taught the various methods of staining technique, and pre-

paration of slides for his individual study. To ensure the

most accurate results, so far as the relationship of tissues are

* Employed in the Laboratory of Histology, Howard University Medical Department,

Washington, D. C.

292 J. MELVIN LAMB:

concerned, as well as for their immediate preservation,

formalin has been used as a hardening and fixing agent.

From the time the selected material starts upon its course of °

preparation it is designated numerically, and the name of the

object or specimen immediately entered in a register, which

I shall describe later. A great waste of time and the loss of

many valuable specimens result from the placing in the single

preservative of specimens which were not previously marked

for identification. The method employed now, and which

has worked’ favorably, is to tag each preparation with a

specially prepared pure tin tag. The tagging material may

be procured in sheet form and of very thin quality, and tags

of any size desired by the preparer can be made by simply

marking off the dimensions upon the sheet. It is my custom

to prepare, say, 400 tags at a time, and number them in

serial order by means of small dies and afterward cutting the

sheet into strips. The most convenient size I have found to

be one inch by three-sixteenths. When cut of this size they

take up very little room in the smallest specimen jars, allow-

ing of many preparations to be placed in a single bottle.

With a small punch, at the right hand side of the tag, a hole

is made, through which a strong, but delicate, linen thread can

be attached for the purpose of fastening the tag to the speci-

men. It is found most convenient to fasten these to the

specimen by allowing, say, only 13 inch of the string to pro-

ject. If they are made longer, and many preparations are

put together in a jar, they are apt to become knotted and

considerable delay is caused in separating preparations while

passing them from one reagent to another. These tags have

several advantages: they are perfectly preserved in any of

the common preservative fluids without tarnishing, corroding,

or in any way obscuring the number which has been stamped

upon them; if dies are not handy, the number or even the

name of the preparation can easily be scratched upon the tag

with the point of a sharp instrument; they can be used

repeatedly if it is a question of economy in the purchase of

the material, although it is extremely cheap and if one is

SOME METHODS OF HISTOLOGIC TECHNIQUE. 293

conducting considerable work it is more satisfactory to keep

up a consecutive system of numbering. I prefer the numeri-

cal registering of preparations for the following reason:

There is no possibility of duplication, and furthermore, with

the numbers properly described in the alphabetical register

prepared for the purpose, the preparation is known from the

beginning to the end by its number, and no possible confusion

can result.

The material secured for future microscopic preparation is

immediately tagged in the manner before described, and from

that time goes forward through the various fixing, hardening,

embedding and staining reagents with the tag affixed. If

properly attached to the most delicate anatomical prepara-

tion they are not likely to get away from it, if ordinary care

is used; in dense tissues it is almost impossible, without

destroying the tissue, to separate them. It is my custom,

when preparing a number of fresh tissues, to give them their

respective serial numbers, carrying at the same time through

the various reagents until the point of embedding is reached,

when a further and special use of the tag presents itself. I

formerly embedded all preparations in the more common

forms of water bath. So far as the embedding process was

concerned, it was as perfect as the method I now use, but it

had the disadvantage of always having the paraffin in metal

cups, which made it impossible, without exceptional condi-

tions of light, to define one specimen from another. I now

employ ordinary glass cylinders, commonly made for staining

jars, and place my specimens in the paraffin in a hot-air

bath governed in the regular way with a thermostat,

After the allotted time for proper infiltration, one can open

the door of the bath and readily see any preparation through

the clear melted paraffin in the glass cylinder. As it is of

importance just at this stage of preparing, I should have

stated that it is particularly necessary to attach the tag to the

specimen in such a way as to indicate that the preparation

should be placed in the imbedding block in a particular posi-

tion. It takes but a moment to do this at the time of cutting

294 J. MELVIN LAMB:

out material, and saves time, which is of great importance,

at the actual moment of embedding, when, if the process is

delayed too long, the saturated specimen stiffens and the

surrounding paraffin in the mold is not of the same density.

The special advantage of the tagging system at this point,

that is, in transferring the specimen from the bath to the

cutting block, is that you can seize the tag with your forceps,

withdraw the specimen from the melted paraffin and instantly

transfer it into the mold which is to receive it, and which has

previously been filled with melted paraffin. For these

molds I have used fora number of years small sections of

lead pipe, which I keep in stock of four or five different

diameters, also of several different sizes in lengths from

inch to 2 inches. The advantages of molds of this kind

are that they are sufficiently thick to be firm on the base,

when touched with a little melted paraffin and placed upon

an embedding slab they are firmly seated and prevent the

melted paraffin from running out at the edge, and further-

more, when the block becomes hard with the enclosed pre-

paration, the specimen is without any trouble or unnecessary

pressure removed from the mold. The specimen is trans-

ferred from the bath to the embedding mold, and when placed

in the desired position for cutting, the metal tag is allowed

to drop over the edge of the mold. As will be readily seen,

if you remove either a few or a large number of embedded

blocks from these molds, the firmly-attached tag serves to

identify the preparation at any time. As there is always an

excess of paraffin about a piece of tissue, I immediately

trim away until the block is ina suitable shape for the jaw of

the microtome, taking care not to cut the attached string,

and after it is properly prepared I gently heat the bottom of

the paraffin and press my metal tag directly onto it. This

keeps the number conveniently attached to the block for

future use.

Another point of great convenience I have found to be in

the employment of carton boxes, of the character and size

accompanying this paper. It was formerly my custom, in

SOME METHODS OF HISTOLOGIC TECHNIQUE. 295

the care of a large number of preparations, which were accu-

mulated from years of hospital and laboratory work, to wrap

the paraffin blocks in special paper wrappers and number

and label these; they were then kept in compartments

accommodating fifty each, in numericalorder. As few prepa-

rations were of uniform size, the collection of blocks for ready

reference in this way was far from satisfactory. As soon as

a block has been prepared for the microtome it is immediately

placed in one of these carton boxes, which is numbered to

correspond with the preparation ; these boxes being uniform

in size, and adapted to the largest sized preparations com-

monly used, are most conveniently kept in a cabinet contain-

ing shallow drawers which will hold 200 boxes each, one

layer deep. The cabinet I use consists of six such drawers,

will hold 1,200 blocks arranged in this way, all in numerical

order, and turning from the index to the cabinet, any desired

block can be secured at once, and of course is readily returned

to its place.

Concerning the matter of indexing one’s material ina large

laboratory, I find the following plan to work to my entire

satisfaction, having had it in practice for about five years,

and it has met all my requirements. I divide my material,

as the work in my laboratory has been duly divided in the

normal and pathological instruction, into these two respective

classes—Normal and Pathological. Taking several of my

most comprehensive works treating of each of these subjects,

I analysed the indices and prepared an index of my own,

which was the result of getting together the essential points

contained in these text-books. Using an index book, I then

placed in it, in strict dictionary order, the essential subjects

which I expected to collect in normal histology and in patho-

logy. In my register proper, contained in the same book, I

devote one-half of it to the normal subject and the other half

to the pathological. The material that I had at that time,

which was not of small amount, I then entered, allowing a

suitable division of space for the title, date, and description,

and any memoranda relating to it in its proper place on the

296 J. MELVIN LAMB:

page of my register, where it bears a corresponding number

of the block. Under the subject, then, to which this parti-

cular preparation belongs, say angioma, for example, I refer

to it in my already prepared index simply by number. The

index, on the whole, was a very complete one in the begin-

ning for the purpose for which it was intended, and I have

added very few titles in the long time it has been in use. It

shows at a glance about how much material I have of any

subject, refers me to the blocks instantly by number, and

shows me in what material or in what subject I am scant, or

in which I have nothing at all; in other words, it is a good

index of the desiderata, as well as what you have on hand.

In my register, as I receive material, I enter the title of it in

the order it is received, whether it be normal or pathological.

In my index I separate the normal from the pathological,

although contained in the same alphabet and upon the same

page. I index the normal subjects in black ink and the

pathological in red. With an index of titles of considerable

size, as this one is, I believe this method reduces to the least

possible space the large number of subjects, and still allows

ample room for the entering of a great many reference num-

bers; this serves the double purpose of an index by referring

to the proper location of that particular material in the

cabinet.

Just another point regarding matter of technique, but one

which may prove useful to some member of the Society, as

it has proved to me. In the last dozen years I have followed

through all the various stages of fixing preparations to the

slide for staining purposes, and have tried with more or less

success about everything that has been recommended for this

particular purpose. During the last few years I have used

the common gelatin mixture which is recommended by Dr.

Piersol and Dr. Gray, but found that in certain methods,

while it had many advantages, it had its disadvantages also.

The most trouble was experienced in staining with the

hematoxylin stain and contre stain. I found when it was

SOME METHODS OF HISTOLOGIC TECHNIQUE. 297

used according to the formula first recommended, namely

about half per cent., that it was not uncommon for the

extremely delicate gelatin film to take up a small amount of

the stain, especially about the border of the preparation. I

used it even as dilute as one-tenth per cent., and yet, in some

cases, with the same troublesome result. Every effort and

much time was spent in freeing the slide from the excess of

the gelatin mixture, but, nevertheless, there was always a

small amount of it perceptible.

I am indebted to Dr. Walter Reed, U.S. A., for the sug-

gestion of the method which I now employ, and have used

with perfect success. Knowing that he was using similar

methods of staining, I asked his experience as regards a

fixative. He informed me that he had, in some cases, simi-

lar trouble, and told me that he was using only distilled water

for the purpose of fixing sections on the slide. I followed

his suggestion, and since that time, now nine months, it has

been extremely rare for the preparation to become detached

from the slide. I willsay that, as an illustration, I cut and fast-

ened to the slide, by this method (simply placing the section

upon the distilled water), 1,640 individual sections. These were

afterwards carried through the usual process of staining, clean-

ing, etc., and without the loss of a single section. While

the method is in the main commonly understood, it may not

be out of place to say, in a few words, how time and labor is

saved in this part of the work. It is commonly my custom

to prepare twenty-four or more slides at a time of a particu-

lar object; I place these in a tray holding two dozen, which

is commonly employed with the ordinary drying bath, the

slides depending upon the size of the section, are covered

with distilled water, and the sections cut and placed upon the

water. The entire set is then placed in my drying oven

sufficiently long, and at a proper temperature, to smooth the

sections entirely, taking care that the temperature never

reaches the melting point of the paraffin. The tray of

slides is then removed, each section accurately centered in

the desired position on the slide, the excess of water allowed

298 SOME METHODS OF HISTOLOGIC TECHNIQUE.

to run off, and the slide placed upon end in a rack for drying.

The racks that I employ, while not original in any sense, are

well adapted to this special part of the work, and I submit

one for examination. They are made to hold seventy-two

slides, a very convenient size, and of a material which will

not warp and allow of an irregular arrangement of the

slides.

HISTOLOGY AND METHODS OF INSTRUCTION.

SIMON HENRY GAGE, B. S., ItHaca, N. Y.

In the preface to the first edition of his Handbook of

Human Histology, Kolliker made this significant remark:

‘*Medicine has reached a point at which microscopical

anatomy seems as necessary for a foundation to it as does

the gross anatomy of the organs and system; and when a

profound study of physiology and pathology is impossible

without an exact knowledge of the finest structural details.”

If this was in the main correct in 1852, when Kolliker first

wrote it, how much more is it so at the present day when not

only medicine, but the great science of biology is taking

such a prominent position in the minds of men. Indeed, in

its broad aspect medicine is but one of the details of biology,

and pathology is biological activity perverted by abnormal

influences and environment; and since the time when Vir-

chow’s cellular pathology appeared, it has been known that

the real seat of this perverted activity resides in the micro-

scopic elements or cells which compose the different organs

and tissues. Likewise is it known with the greatest cer-

tainty that all normal activity goes on in the microscopic

elements making up the tissues ; and finally the germs of a

new generation, the bearers of heredity by which the past

reappears in the future, are likewise, in most cases, micro-

scopic elements. In a word, without the microscope,

knowledge would be turned back a century and the certainty

concerning many things in biology today would give place to

the baseless speculations of the dark ages.

All teachers of histology have, of course, the same general

object in view, viz.: to give their pupils a knowledge of the

300 SIMON HENRY GAGE :

microscopic structure of the body. Naturally, and of neces-

sity the way in which different teachers go to work to give

their pupils this knowledge will depend on the teacher's view

as to the special end to be attained by the study, and

secondly on the facilities he has at his disposal. The views

expressed in this paper may not accord with those of teachers,

in whom experience and special surroundings have given rise

to fixed convictions, but it is hoped that some of the younger

teachers may get suggestions from it that will aid them in

making the most of their surroundings and facilities; it is

hoped also that the subject of histology will be seen by them

to be vitally important for an understanding of physiology,

morphology and pathology. It is hoped also that the end of

histology will not seem to any to be reached when an organ

or tissue has been fixed, hardened, cut with an expensive

microtome, stained in brilliant colors and finally embalmed

in Canada balsam. It is hoped rather that all of this labor

and pains may be seen to be only to help one see the

physiologic, morphologic or pathologic processes and rela-

tions exhibited by the tissue more clearly. If the micro-

scopic preparations have no such meaning to the student

then they are no better than so many Chinese puzzles.

It seems to the writer that the first step in histology is a

thorough study of the chief instrument used, the microscope.

The microscope is to aid the eye in seeing what is invisible

or not satisfactorily visible without it, and unless one knows

something of the methods of making this helper to vision a

real helper, much time will be wasted. This is especially

true of the better forms of instruments. One can use with

some satisfaction a simple magnifier without instruction or

much study, but a good modern, compound microscope to be

of much use must be well understood; one must know its

possibilities and limitations. It seems to the writer that

time is really saved for histology by devoting a few weeks to

the microscope itself, and to the methods of micrometry,

drawing, the use of the micro-polariscope, the micro-spectro-

scope and other accessories. Otherwise one must learn

HISTOLOGY AND METHODS OF FNSTRUCTION. 301

these things when he is trying to make use of them in solving

some problem in actual work.

It may naturally be asked what kind of a microscope is

necessary for the pursuit of modern histology ? While a

great deal of excellent work may be done with comparatively

inexpensive apparatus, costing from $25 to $50 and magnify-

ing from 25 to 500 diameters, one cannot follow out the finer

details in histology and pathology with such an outfit, and in

some parts of pathology, where bacteria are involved, one

would be practically helpless. Some such outfit as the fol-

lowing seems necessary: Dry objectives of 50 mm. (2 in.),

16 mm. (3 or } in.), and 3 mm. ({ in.), and a homogeneous

immersion of 2 mm. or I} mm. (I-I2 or I-16in.) There

must be some form of substage condenser. This, like the

objectives, will serve one in proportion to its excellence.

The stand of the microscope should have a coarse and fine

adjustment for focusing, the pillar should be flexible, so that

it may be used in either the vertical or inclined positions, and

the substage should have a rack and pinion adjustment for

the substage condenser, and an arrangement for centering.

Fortunately such an outfit can be had at the present day for

less than $100, if supplied with ordinary achromatic objec-

tives ; but the cost is much greater if the best achromatic or

apochromatic objectives are obtained. Itis of the greatest

advantage also to have a mechanical stage of some sort.

The removable mechanical stages after the Tolles-Mayall

pattern are inexpensive and most satisfactory.

For laboratory work there are two methods, the one

allowing students to come at their convenience and accom-

plish as much work as they can or wish to. The other plan

is to give a medium amount of work, which must be accom-

plished in a giventime. The students are required also to

come in regular sections. The last way seems to the writer

the best. Experience has shown that regular sections, in

which the teacher devotes his whole time to the laboratory,

yield better results. There isa kind of momentum gained

in this way that overcomes the inertia of the less energetic,

302 SBMON HENRY GAGE:

and for those that get through with the small amount of work

that must be assigned for a lesson there is abundant oppor-

tunity to consult monographs and go more deeply into the

subject than is required of the average student. To conduct

a class in this way, however, necessitates abundant, well-

lighted space, plenty of tables and microscopes, and other

laboratory facilities. It can be readily seen that laboratory

work in histology carried on in this way requires an expensive

plant. If the subject is to be taught at all, this is the only

economical way, however. To keep a laboratory open all

day and every day, the teacher being on duty all the time, is

wasteful and the results unsatisfactory ; as unsatisfactory and

uneconomical as it would be to divide a Greek class of twenty

up into five to ten sections for recitation. The last section

would hardly gain much inspiration from the teacher, and

such a teacher would not be likely to add much to compara-

tive philology or anything else.

In the actual instruction it is believed that there should be

a combination of lectures and laboratory work. The lectures

serve to give the students broad and general ideas and the

relations of the subjects to each other; that is, they give the

fundamental facts, principles and relations, which are the

result of the investigations of the best workers. The best

books and monographs are referred to and shown, and put at

the students’ disposal. This is done because it is believed that

every one should take advantage of the gain made by his pre-

decessors and not try to start at the beginning. Life is too

short for that, and progress would almost or quite cease if the

gain made by our predecessors could not be made use of.

From a long observation it is believed that the student who

has the power to make independent investigations should

have these helps, so that he may recognise the attainments of

others and start from their vantage ground to explore new

fields. For the student who has not the power for original

investigation this is the only way to help him. He cannot

go where there is no path.

In the second place there should be abundant opportunity

HISTOLOGY AND METHODS OF INSTRUCTION. 303

for laboratory work where the student is brought into direct

contact with the truths of nature in nature herself, and if he

is an honest man he must work very hard to make out these

truths, no matter how much help he has been given by

lectures and books.

In the laboratory work each student should learn and

practice all the principal methods. A preparation made by

the student himself from getting the tissue until it is mounted

and labeled means something to him ; it is connected in a very

definite way with the organ or part in the animal. He also

gains skill in manipulation, and without skill in manipulation

no real progress can be made in any science. Exact notes,

with dates and drawings, are necessary to avoid vagueness

and to prevent the student from deceiving himself in the

belief that he has gained certain knowledge when he has not.

These notes and drawings, and the students’ specimens, duly

labeled and catalogued, should be most conscientiously

scrutinised by the teacher. They give him an opportunity

that nothing else can to help the student by correcting

erroneous conclusions and by aiding him in gaining skill in

manipulation. It may well be asked, however, if it is possible

to get aclass through the tissues and organs of the animal

body by having each student perform all the operations for

himself. It is admitted that the time necessary would be

too long, and for most of the students much time would be

unnecessarily used in mere mechanical operations. The

plan advocated is to have each student learn all the funda-

mental processes in modern histology, and learn them by

repeated operations, but the loss of time by mere repetition

after the processes have been mastered may be avoided with-

out injury by furnishing most of the preparations either

already cut or imbedded ready for cutting. It is believed

that every preparation, with rare exceptions, should be in

part at least, the work of the student. If then for these

partly prepared preparations full data are given concerning

the methods used the student will have no trouble in making

the proper connection mentioned above when he performed

304 SIMON HENRY GAGE :

all the work himself. It is believed that the ground can be

covered in this way and it is known from experience and

observation that the intellectual independence gained by the

personal work of each student will repay all trouble on the

part of the teacher—for it is more trouble to guide the

student than for the teacher to do the work himself. The

student will gain also the power to use the work of others,

and to judge it at its true value as he could in no other

way.

In the actual work carried on by the writer, lectures are

civen to the entire class, and, then, for the laboratory work

sections of about fifteen are taken for not less than two hours

at atime. Ifaperiod of less time were given, so much of

it would be used in getting ready to work and in clearing up

that not enough actual, productive work could be done to

repay the effort, Each student is given the use of a locker ;

each one prepares nearly allof the reagents used by him, and

each one learns the methods of isolation, of sectioning by the

collodion and by the paraffin method, both with simple and

inexpensive and by the best modern apparatus ; and all have

opportunity to see the method of making frozen sections, so

largely used in diagnosis in pathological work. There is

a large cabinet of specimens illustrating microscopy,

histology and embryology, made and labeled and catalogued

with all possible care, to serve as models for the students and

for reference. The cabinet has been found very valuable for

stimulating independent work. If one sees only figures of

microscopic objects he may feel that to make actual speci-

mens which shall show the objects with equal clearness

would be impossible for a student, but if such specimens

are at his disposal he is stimulated and encouraged to

prepare similar ones for himself. He soon learns also, in

studying actual specimens, that many of the figures in the

books are composites, made by combining the best features

of several preparations.

For convenience, the animal body is divided into the fol-

lowing groups of tissues and organs. The arrangement is

HISTOLOGY AND METHODS OF INSTRUCTION. 305

more or less logical also on embryologic, physiologic and

morphologic grounds: |

I. Epithelia, including endothelia.

2. Connective and supporting tissue (Areolar tissue, ten-

don, ligament, bone, cartilage, etc.).

3. The muscular system.

4. Blood and lymph, z. ¢., the fluids of the body and

their corpuscles.

The blood and lymph vascular system.

The digestive system.

The respiratory system.

The genito-urinary system.

The skin and its appendages.

o. The nervous system and the organs of sense.

Bee See a

In teaching, the following guiding principles have been

followed :

1. It has always seemed to the writer that one of the

most important steps in the knowledge of the structure of

the tissues and organs is a thorough knowledge of the gross

anatomy. The histologist must, first of all, be a thorough

naked-eye anatomist. He must also be a physiologist, and

he will naturally become an embryologist, for without the

knowledge that embryology gives, the adult structure is fre-

quently unintelligible, and without physiology, structures are,

in many cases, meaningless. The wise histologist is then a

physiologist, an embryologist and an anatomist. From the

naked-eye appearances he passes as necessity requires, from

the contemplation of organs and tissues, first to a low power

and then for the finer and finest structural details to the

highest powers available. But he never loses sight of the

fact that the details alone are far less intelligible than when

they are correlated with the organ or tissue to which they

belong.

2. It seems so natural and logical in teaching the funda-

mental facts concerning the morphology and structure of the

body to refer to the mode of development, that for several

306 SIMON HENRY GAGE:

years the students have not only been taught in lectures from

the embryological standpoint, but each student in the begin-

ning has put into his hands, in the laboratory, preparations of

the ovarian ovum to represent not only a typical cell, but the

fundamental fact that the complex body of the largest animal

is derived from the ovum. Then preparations of the blastula

with a single layer, representing in a general way a simple

epithelium, are studied, and then the blastula with a wall

several cells thick, representing in general a stratified epithe-

lium. Other preparations are studied, showing clearly the

mode of formation of the axon or notochord from the ento-

derm, and of the neuron or central nervous axis from the

ectoderm. After studying these preparations it means some-

thing to the student when he reads or hears in lectures that a

given tissue or organ is derived from one or the other of the

germ layers. *

3. Each tissue is studied fresh, so that correct notions

may be gained of the natural appearance of the organs and

tissues and their structural elements unaffected by reagents.

4. Every organ and tissue is studied alive, so far as pos-

sible, in order that the function and the structure that per-

forms the function may be seen at the same time and the two

properly associated. .Students who see only prepared speci-

mens can hardly avoid gaining the impression that the gor-

geous red, blue and purple colors belong to the natural

tissues, and would be so found in dissecting an animal.

Indeed the histologist who studies his subject profoundly

looks upon the adjuncts of stain, etc., as necessary evils at

best, and he never feels quite sure that the appearances seen

in these much-stained and manipulated specimens are true

expressions of nature, or whether they are structures of his

own creation (artifacts), until he has seen the appearances in

the living substance, where the pitfalls of color and Canada

* The preparations used in my laboratory are the small ovarianova foundin the ovary

of a young Amélystoma, or those left after spawning. All sizes are seen, giving also a hint

that the different sizes mean the different crops of eggs, so to speak, that will reach matur-

ity. The segmenting ova of Amblystoma are admirable for showing the blastula, and the

formation of notochord and nervous system.

HISTOLOGY AND METHODS OF INSTRUCTION. 307

balsam have no place. (See the preface to Foster and Lang-

ley's Practical Phystology.)

5. All glands should be studied in various phases of their

activity and repose, so that the structural features present in

each phase may be associated with the functional ‘condition.

In a word, it is greatly to the advantage of the student if the

histology he studies is truly ‘‘ Physiological Histology.”

6. The student will gain a truer insight into the structure

of the body if he understands at the beginning that every

organ and every tissue as it is found in the body is really a

complex ; that is, it is composed of several tissues and of

ground substance. For example, muscle is composed not

only of the characteristic structural elements, the muscle

fibers or cells, but mingled with these are connective tissue

and blood vesseis, and nerves are abundant. Even in

epithelium the cells are not the whole of the tissue, for there

is always present the cell cement uniting the cells. In con-

nective tissue, the characteristic elements or cells, so promi-

nent in this tissue in embryonic life, are so far pushed into

the back-ground by the intercellular or ground substance,

that the tissue is actually characterised, not by the cells, but

by the ground substance. Thus we speak of cartilage, liga-

ment and bone and the other members of the connective

tissue group, having in mind almost altogether the inter-

cellular substance, and not the cellular elements.

7. Of necessity, as well as preferably, every general course

in histology’must be a course in comparative histology, as

structural details are not all shown with equal clearness in

any one form and not obtainable at all, or only with difficulty

in some. For example, hair is not found below the mammals,

and the fibrin network in the blood and lymph is far more

satisfactory in man and the other mammals than in Amphibia

and fishes, while nucleated red blood corpuscles are found

with difficulty in mammals, while they are normal in non-

mammals. As the course is then to be really one in com-

parative histology, the fact should be distinctly expressed,

and the student not left to infer that a structural detail seen

308 SIMON HENRY GAGE:

in one animal would be found exactly similar in all others.

On the other hand, it should be most emphatically brought

out that whzle there ts unity in type there ts much diversity

in detail, This can be demonstrated by each student in

comparing the striated muscle of mammals and Amphzdza ; or

to take nearly related forms, the igamentum nuche of the ox

and other grazing forms is almost purely elastic tissue, while

in the cat and man it is largely white fibrous tissue, and far

less prominent. This point has been insisted upon, because

if any one looks through the pages of any work on histology,

even though ‘‘human histology” may be printed on the title

page, he will find it really a comparative histology, with the

comparisons left out. That is, there will be figures of struc-

tures from widely differing animals to illustrate the structure

of the different tissues, and frequently even the accompany-

ing legend or explanation gives no hint that the tissue

figured is not from man. Naturally the student concludes

that the tissues are exactly alike in all animals. If on the

other hand homologous parts from different animals are

carefully compared many of them will show marked differences

in detail, although the type of structure is unmistakable.

8. If it is necessary to keep in mind the differences in

anatomic details in different animals, so is it equally

important to know and to learn to demonstrate differences

in structural detail of the same tissue or organ in the same

animal in different phases of activity, in vigorous youth and

in senile decay. Indeed, the differences in structural appear-

ance of the pancreas, for example, before and after secretion,

is as great as the apparent structural differences in quite

widely differing forms. It is, therefore, necessary for a com-

plete understanding of structural appearances to keep physi-

ology constantly in mind; and as so few animals are in

perfect health, possible pathologic variations from the normal

appearance must be looked out for, otherwise one might in a

limited’ number of observations decide that merely temporary

or even abnormal structural appearances were characteristic

of the animal under investigation.

HISTOLOGY AND METHODS OF INSTRUCTION. 309

The above statements, while they apply to the study of

histology in general, have special reference in the main to

elementary courses, where the students are introduced to the

subject and are naturally imbibing the spirit of the study.

The course outlined above would require considerable

time. It could not be satisfactorily gone over in less than

one college year, in a course consisting of two lectures per

week and three laboratory periods of two and one-half hours

each.

For research in this, as in any other subject, there must

be great liberty as well as good facilities for work and experi-

mentation. Mistakes will be made and time apparently

wasted ; but the mistakes and the apparent waste of time are

a part of the ‘‘dead work” that must be done by all those

who aspire to perform truly advanced work and to add to the

sum of human knowledge. .

Besides the numerous addresses and special papers that

have appeared the student and teacher will find the six

books named below especially helpful and inspiring :

An American Text-Book of Physiology. Edited by Wm.

H. Howell, of Johns Hopkins. The writers besides the

editor are: H. P. Bowditch, J. G. Curtis, H. H. Donald-

Soper. t:ee, W. P. Lombard, :G> Lusk; Woe Porter:

E. T. Reichert and H. Sewall. Philadelphia. 1896.

Bernard, Claude, Cours de physiologie générale du Muséum

dhistoire Naturelle. Lecons sur les phenom nes de la vie

communs aux animaux et aux végétaux, two vols. Paris.

1878-1879.

Foster, M.—A Text-Book of Physiology (1877 to 1896).

London and New York. The sixth edition contains much

histology. All the editions correlate structure and function

in an admirable way.

Metcehnikoff, Elias—Lectures on the comparative patho-

logy of inflammation, delivered at the Pasteur Institute in.

tesiee Cluranslated) from the, French’ by, Fo 2A, and’ E-wH.

Starling, London. 1893.

310 HISTOLOGY AND METHODS OF INSTRUCTION.

Hertwig, O.—The Cell; Outlines of General Anatomy

and Physiology. Translated and edited by M. and H. J.

Campbell. London and New York. 1895.

Wilson, E. B.—The Cell in Development and Inheritance.

Columbia University. Series 1V. New York and London.

1896.

For an excellent article on The Importance of Technical

Instruction in our Medical College Laboratories, see Dr. A.

P. Ohlmacher, Wew York Medical Record, Vol. LXIILI.,

March 21, 1896, p. 374. :

For a view that all microscopical and bacteriological

knowledge is of no assistance in either medicine or biology,

see Dr. Charles G. Kuhlman, in the S¢. Louzs Medical and

Surgical Journal, Vol. LXX. April, 1896, p. 201.

WHAT IS THE BEST METHOD OF TEACHING MICRO-

SCOPICAL SCIENCE IN MEDICAL SCHOOLS?

ViIDAPA, LATHAM, M.D, D:D) )S:,, F. Re Mees.) Gaicsco; IL;

During the last decade, few questions in medical sociology

have attracted greater attention than medical education.

The requirements of our colleges not being equal with those

of other countries, nor with other departments of education

in this country, it was but natural that the profession, as a

whole, the medical press and societies should join in a

demand for needed reforms. My apology is due to you for

bringing this subject before you in a necessarily imperfect

way ; but I hope for a discussion of ideas, and to learn other

ways and means, rather than to give much of value.

By microscopical science, the scope of this paper includes

those subjects taught in medical colleges wherein the micro-

scope plays an important part. We shall consider:

(a). How much time should we devote to these subjects,

out of a four years’ course of nine months each, including

holidays and examinations ?

(6). In what years can the subjects most profitably be

placed ?

(c). By what methods should each of these subjects be

presented to the students ?

1. Lectures and recitations.

2. Laboratory work.

(2). What are the best modes of testing or giving credit

for work done in each branch ?

(a). In arranging a medical curriculum, it is a matter of

great difficulty to divide the time fairly among the several

subjects, giving each its due amount in proportion to its

312 VIDA A. LATHAM:

importance. In far too many medical schools, a proper

balance is not preserved, one subject being allowed to usurp

time really belonging to another, to the great detriment of

the student. This is especially prone to occur where there

is a considerable difference in the teaching power of the pro-

fessors of the respective chairs.

Not long ago the committee of the Association of Ameri-

can Medical Colleges, devoted to bacteriology twenty-five

lecture hours and 150 laboratory hours, a total of 175 hours,

while in pathology, fifty hours of lecture attendance and 100

hours of laboratory work were deemed sufficient—less by

twenty-five hours than the time required for one of its sub-

divisions! Some colleges prefer to give only two hours a

day to laboratory work and one to lecture. In such work as

bacteriology this seems to me unfortunate, especially when

the hours are arranged with an interval either too long or too

short. Many students lose the value of their cultures

through long waiting, or the growths have time to become

contaminated.

(2). As regards the placing of the several subjects much

difference of opinion exists. Histology with embryology

usually comes in the first year. It may be questioned

whether it would not be much better to put embryology in

the first half of the second year, when some knowledge of

osteology, elementary anatomy, physiology and histology

has been taught. Many colleges place bacteriology in the

first year. This is to be strongly condemned, I think, because

bacteriology requires a great deal of dexterity in handling

tools and instruments, including oil-immersion lenses, and

also a fair knowledge of physiologic and organic chemistry,

and some acquaintance with diseases. I am here referring

to a complete course, and not to the mere elementary out-

lines and details so often taught. The proper place seems

to me to be in the second half of the second year, after the

chemical course is finished, when we have had some elemen-

tary general pathology, when the question of saprophytic

bacterial poisons can be better understood. The formation

TEACHING MICROSCOPICAL SCIENCE. S13

of sepsin and its resultant irritative action on the tissues

plays an important part in the study of inflammation ; and

the infective circulatory diseases certainly can be better

appreciated after an acquaintance with bacteriology. The

same is true of the infective granulomata. .What can we

intelligently teach of tuberculosis or leprosy if we know

nothing of the bacilli occurring in the same, and their effects ?

Without any doubt, bacteriology should go hand in hand

with pathology, or closely following it, and both should

have been preceded by some practical laboratory work in

histology and elementary biology. Indeed, we have no

business to teach pathology to students who have not com-

pleted theoretical and practical histology, as is now so often

done, especially in colleges that accept the B. A. degree as

an equivalent of one years work. Only a science, and never

a classic degree should be accepted as such equivalent, and

it should include Latin or Greek, German and French as well

as technical work, which I believe at the present time it

does in most universities. No student can study pathology

profitably without first knowing his histology, and such an

attempt should be forbidden by the Faculty of the school.

Unfortunately the rule too often stands ‘‘each man for him-

self,” each professor knowing and caring but little of any

chair but his own, and the student certainly not the wisest

judge of the order of his studies. I enter an emphatic pro-

test against the faulty grading of students. One who is

allowed to begin work in a course for which he is not pre-

pared is a hindrance to the demonstrator, a detriment to the

whole class, and besides, he is seriously wronged himself,

since he cannot understand what he is trying to learn. The

only resource for him is a special tutor.

How then shall we arrange the teaching to obtain the

necessary practical results for a medical student in a limited

time, with limited apparatus and demonstrators ?

If the first year is divided into first and second semesters,

let the class begin anatomy and general biology, as outlined

in Parker's or Campbell’s elementary biology, or in Huxley

314 VIDA GAY LEASE EVAM ©

and Martin’s. Then follow with the dissection of a cat or

dog, using Howell’s Dissection Manual. The frog is rather

small for beginners, but those who prefer it can work easily

from Marshall’s little book, or McAlpine’s Zoological Atlas.

Martin and Moale, Vol. III., is a good guide to the dissection

of arat. The particular animal and text-book selected is of

minor importance. Any one of them, carefully worked

through, will fix the main anatomical and osteological facts,

and give the requisite manual dexterity for later work on the

human body. Nothing is more absurd than to place raw

medical recruits beside a cadaver, after reciting a few lessons

from a book, and expect them to dissect half a human sub-

ject in six or eight weeks, working two hours a day. Much

better, more intelligent work can be done after the general

preliminary training advised above. Elementary chemistry

can well be taught at the same time. Indeed, the repetition

of terms in the different classes, the explanations given and

positions indicated, all amount toa practical translation of

the Latin terms in osteology, myology and so forth, and

serve to fix in the Freshman’s mind what otherwise would be

lost.

Embryology is best done in the spring months, when eggs

can be easily obtained. In the meantime, histology is

occupying some six hours a week, four in laboratory and

two in lectures and recitations. Here we are increasing our

dexterity and learning the application of anatomy and

physiology, and their intimate relations with each other and

with chemistry. In the histological laboratory, what shall

we teach the student? First, an intelligent use of the micro-

scope, its construction and optics. Then methods of harden-

ing, cutting and staining sections, each member of the class,

in turn, being instructed to cut sections with the freezing

microtome and bottle and label for the class use, so that

there are always plenty on hand for testing any desired

staining method. And finally, a systematic study of the

histologic structure of the tissues and organs of the human

body.

TEACHING MICROSCOPICAL SCIENCE. 315

In bacteriology, no single text-book fulfills all requirements.

Abbott is very useful, but personally, I think, for a first book,

Kanthack and Drysdale’s little work is most excellent ; for if

a student be given a culture, all details are practically laid

out for him, to the great economy of the demonstrator’s time,

the book being on the plan of the old standard and excellent

form in Huxley and Martin’s biology.

The student in bacteriology must be taught to make clean,

well-stained preparations of some organism, with exactness,

so that every bacterium is sharply seen when examined.

The poor, hazy, half-stained and often milky smears allowed

are too commonly found in students’ hands and reflect no

credit on teacher or pupils. In addition to making neat,

accurate mounts, the preparation of media and making

inoculations show the student how to work—which is far the

most important—namely, in a clean, orderly, concise manner.

Elaborate methods and appliances should be avoided as far

as possible, so that the student can soon learn what is essen-

tial and how he can best obtain or make things for himself,

after he goes out from the laboratory. Assign to one

student a given subject, and require a complete examination

and report. Teach him how to proceed to make an original

investigation, what are the necessary steps to follow, how to

isolate and obtain his own pure cultures from raw material.

When he can do these accurately, he can safely be said to

know the main processes and principles, at least, in making a

bacterial investigation, no matter where he is situated. And

this is precisely wherein, I think, our graduates of medicine

are lacking. Few of them are able, after leaving college, to

proceed to make a complete investigation, on their own

resources. Their knowledge of classification, experimental

inoculation and subsequent recovery are too vague to be

trusted, even by themselves. It is not right to urge that all

laboratory work should be out of the way by the end of the

second year, as many colleges do, by requiring junior and

senior students to spend all their spare time at clinics, for-

bidding them to take laboratory courses during the third and

316 VIDA A. LATHAM:

fourth years. It is a fact that students are very prone to get

their earlier work hidden away in deep recesses, and to for-

get how to do things they formerly did well; and it is easy

to understand how a student who ‘‘finished” his general

pathology and bacteriology in the second year may not be

able to apply them to his practical medicine and surgery.

General pathology should commence in the second year,

and from the first it should be the aim of the instructor to

show the deviations from the normal by comparison, and by

demonstration of actual specimens, under supervision of the

lecturer, who has arranged typical places in the field, and has

illustrated them by the lantern. In this course, celloidin and

paraffin cutting can be given, as well as special modes of

staining, particularly each of the special reactions, as amy-

loid, and the like. Double staining can here be practised to

advantage, and the specimens can be then studied and drawn.

Personally I think drawing is best left out after the biologic

and histologic courses, because it takes a great deal of time

which the student can ill afford to spare. Do not infer that

I wish to depreciate this important subject. In science

courses, it should certainly hold a strong place. But in

medical schools the time is too short, and many of the

students have to do outside work to pay their way through

college. For the majority of our classes, utility alone is to

be considered.

Of far greater value than the ability to draw well, is the

practical application of the knowledge required. Pathology,

in its truest and fullest sense is to be defined as the theory

and science of medicine, to the understanding of which

normal structure and function are necessary. True, it is

impossible to teach all medical science from the chair of

pathology, but the pathologist should maintain clearly the

relation which disease bears to the normal. bodily condition.

He must detail, as completely as the state of science permits,

the altered modes of function of diseased organs, the external

manifestations of these altered functions, and their remote

and direct. effects upon the economy. The habit of teaching

TEACHING MICROSCOPICAL SCIENCE. 317

pathology as a bare mass of facts with no relative bearings

upon physiology, clinical medicine and therapeutics or

surgery is much to be deplored. It is no wonder students

so taught regard mounts as an everlasting bugbear and

nuisance.

The study of medicine comprises three well-known groups

of subjects :

(a). Preliminary studies—anatomy, physiology and

chemistry.

(6). Developmental—those branches which teach the

causes of disease, and the altered functions met in disease—

that.is, pathology.

(c). The application of these studies to the recognition

and treatment of disease—that is practice and surgery. This

shows us that pathology is an intermediate subject between

biology and practice. As certainly as the gun-shot wound,

the tubercular joint, the fractured bone, or the cancer of the

liver take their places in the pathological museum, so should

the altered function be regarded as a pathologic study.

The man who recalls from his book that renal or cardiac

disease may often present, as a symptom, dropsy, is far more

liable to miss entirely the vital point in his examination for

a diagnosis than the man who has been taught to regard

dropsy merely asa manifestation of a circulatory fault, and

who has been trained to seek carefully for the arterial disease,

or for the cause of venous or lymphatic insufficiency along

the courses of these currents whenever examination is pos-

sible. The failure to acquire habits of pathologic reasoning,

of comparing the diseased structure to the normal, the

diseased function with the normal function, of seeking for

etiologic influences within as well as without the body is

often never overcome. The sneering remark that the patho-

logist only makes a post mortem diagnosis, has too much

truth to be overlooked. This overweening influence of the

importance of pathologic anatomy, the confused pathologic

histology and microscopy, as applied to medicine, has been

the cause of the great impetus given the anatomic school of

218 VIDA A. LATHAM:

pathology by the great Virchow and through it our advance

in this line of work has come. There is a pathology beyond

this, however, and for the general practitioner our schools

ought to make every effort not to turn out specialists, but

careful, conscientious, scientifically educated, practical physi-

cians, with the further privilege of study for higher or future

specialistic work if they so desire. For convenience let us

divide pathology into three well marked schools :

I. Anatomic pathology, of which the learned Virchow,

Ziegler, Klebs and Gross are the best exponents.

II. An etiologic school, at whose head stands Koch and

Sternberg, the bacteriologists.

III. A _ physiologic is, but unfortunately, the least

developed, but the most applicable without any doubt to the

wants of the busy practitioner of medicine, for example Von

Jaksch and Vierord and Osler.

The first was created by the doctrines of cellular pathology

of Virchow and has since advanced by the increased facilities

of observation.

The second was made possible by the perfection of the

microscope and its appliances through the energy of Zeiss,

Tolles and by the apparent exhaustion of results of our

anatomic study of diseased tissues. Observations naturally

drifted towards examination in the existence and nature of

parasitic microorganisms and the brilliant successes of this

second school, the etiologic, have caused bacteriology to

almost outgrow its relative importance in the study and

teaching of pathology and almost, if not quite, occupy as high

or a higher position. While the third, the pathologic phy-

siologic, has been limited and failing to attract notice by

experimental work and popularity, because of the difficulty of

demonstration and proof of its principles and details, has had

little or no growth and so far has received from teachers of

pathology not half the attention its practical value demands.

It is this division which makes a man an intelligent prac-

titioner and the ignorance of which makes of him the routine

follower of.other men’s methods.

TEACHING MICROSCOPICAL SCIENCE. 319

No one science should be taught to the exclusion of the

other and especially is this so of bacteriology. It is proper

to teach the nature of microorganisms which are causative,

say of ulcerative endocarditis, that we instruct as to the gross

and microscopic changes eventually made in the affected

valve when the acute stage is over, but at least remind him

of how these changes make known their presence, why they

must finally end in cardiac hypertrophy and degeneration,

and further how these subsequent alterations indicate their

presence, and why such abnormalities in the heart must

result in vascular changes, in lungs, liver, spleen, kidneys

and so forth, and how he may estimate somewhat the rate of

progression and what termination he may expect. Just as

we know therapeutics must always belong to the order of

applied sciences, and will bear the same relation to pathology

in an extended sense as does engineering to mathematics,

therefore, as engineering is applied mathematics so thera-

peutics will be applied physiology and pathology.

One of the most important obstacles to real progress in

scientific development and accuracy, is the want of persever-

ance on carefully devised plans for insuring completeness of

investigation before announcing results. Much of our scien-

tific and experimental work is done in fragments and neces-

sarily results in the development of isolated facts and partial

views, filling the pages of literature with everchanging and

often contradictory inductions. Another obstacle, and a

serious one, lies in the frequent formulation of inductions, or

more properly assumptions for practical guidance, founded

on an inadequate number of facts, and sometimes on mere

analogies. Still a third obstacle is the constant tendency to

concentration of all attention on the results of any new line

of investigation started to the neglect or rejection of facts

and inductions previously well established and the verification

by abundant clinical observation. From this it will be seen

special pathology is assigned for the junior, or better, the

senior year, when the associated studies—medicine, autop-

sies and bacteriology—are well in hand and more profit

320 TEACHING MICROSCOPICAL SCIENGE.

gained by their co-relations, leaving clinical microscopy for

the terminal part of the senior pathology, when students have

access to the wards and can thus intelligently utilise the

material and at the same time increase his laboratory knowl-

edge. In closing, the question of examination of students is

still much discussed, for the lecture is not sufficient and has

many objections. The recitation method is only applicable

to small classes, and for some students who are of a nervous

temperament are not a fair test. The writing and correction

method is excellent but not sufficient. Unless we can insure

honest work, it is a severe tax on the teacher who corrects the

papers and with slow writers does not give them a chance.

It is a good plan to have a debate-day to teach the value and

use of books and journals and so encourage a wider field

of reading and consequent discussion, as well as to elicit

many practical questions on not only the subject in hand, but

its subdivisions and thus aid in showing a student the subject

has a practical value and an intimate bearing with the

sciences, most of which embrace the microscope. This, it

seems to me, is the best method of teaching micro-science in

medical schools.

REFERENCES:

OhlImacher—N. Y. Med. Jour., 1894-96; Pan American Congress Transactions, 1895.

Transactions of Association of American Medical Colleges, 1896, and Jour. Amer. Medi-

cal Association, etc.

THE PRESIDENT’S ADDRESS.*

An Experimental Study of Aperture as a Factor in Microscopic Vision.

A CLIFFORD MERCER, M..D., EF. R. M. S:

It is a well known fact that the image of a point projected

optically is not a point, but always a disc. The diameter of

the disc varies directly with the uncorrected spherical and

chromatic aberrations, and inversely with the aperture, of

the projecting lens. If it were possible to fully correct

spherical and chromatic aberrations, the image of a point

would still be a disc varying in size inversely with aperture.

Microscopists have long been familiar with the effect of

spherical and chromatic aberrations in the microscope. But

the effect of aperture as a factor in microscopic vision is

not generally well understood and is worthy, I think, an

hour’s consideration by this society.

The practical importance of aperture in its relation to the

resolving power of the microscope has been recognized longer

than any explanation of that relation has been acceptable.

Considered theoretically and independently as a factor in

microscopic vision aperture has been almost ignored ; although

as an associate factor, associated with diffraction by the finer

details of microscopic objects, it has received no little atten-

tion. In fact, the final associated effects (in the projected

image) of aperture and of diffraction of light in the plane of

the object are the basis of the Abbe theory of microscopic

vision. This theory and its easily repeated experimental

study are fascinating and convincing. Since its announce-

ment the Abbe theory has been for the most part accepted

as rapidly as it has received serious attention. Nevertheless,

*Revised, extended and newly illustrated for the Transactions of the Society.

322 A. CLIFFORD MERCER :

a few men* while appreciating the labors of Professor Abbe

and recognizing the importance in some ways of his discovery

have called attention to unsatisfactory points in the theory.

The writer, if he may, will submit for consideration these

and some other points and a theory of microscopic vision in

harmony with an experimental study of aperture as a factor

in microscopic vision.

The Abbe theory is said to be applicable only to micro-

scopic vision, to the projection of an image by a microscope

objective and not to image projection by a telescope objec-

tive or any other variety of projecting lenses. On the other

hand, it is said that the theory applicable to the formation of

an image by other projecting lenses is not sufficient to account

for all the effects seen in an image projected by a microscope

objective. Is not such exclusiveness, or limitation, unusual in

the application of a theory to one particular function performed

by essentially the same instrument (z. ¢. a projecting lens),

although under somewhat different circumstances ?

The writer believes that the theory of the effect of aperture

as a factor in microscopic vision is applicable to all projecting

lenses, explaining resolving power and its limitation; that

the diffraction of light by an object is to be considered in the

same category with other changes in direction in incident

light produced by an object, as, for instances, those result-

ing from reflection and refraction; that diffracted and other

rays leaving an object in changed directions, as well as rays

directly transmitted, when traveling the same paths between

an object and the objective are affected alike by aperture ;

and that the final effects in the image experimentally studied

by Professor Abbe are the result of changes above the objec-

tive due to aperture, and not to changes below the objective

resulting from diffraction by the finer details of an object.

A few years ago a portrait lens served the writer in show-

ing the Abbe diffraction phenomena to a number of physi-

cians met to listen to a paper on the theory of microscopic

*Particularly Mr. E. M. Nelson in The ¥ournal of the Quekett Microscopical Club, July,

1890,and March, 1895; Mr. B. Tompson Lowne in the same Journal, April, 1889; and Mr.

Lewis Wright‘in the Exglish Mechanic, Vol. LX [1894].

THE PRESIDENT’S ADDRESS. 323

vision. The phenomena were the same as those with which

most microscopists are familiar experimentally or by reading,

and of which an authoritative account (g. v.) is given in the

Dallinger edition of Carpenters Microscope and Its Reve-

lattons. The portrait lens having a diameter of two inches

and a focus of eight inches exhibited the phenomena on a

large scale as well as a microscope objective exhibits the

same phenomena on a smaller scale.

Early this month [ August, 1896, | a parallel experiment

was tried, using instead of the portrait lens a telescope objec-

tive having a diameter of two inches and a half and a focus

of forty-three inches. An eye-piece was supported about

sixty feet from the objective (z. ¢. the distance correspond-

ing to tube length was about sixty feet, an actual tube of

that length being unnecessary because the experiment was

tried in dark rooms). The source of light was an elec-

tric arc lamp about twenty-seven feet-in front of the objec-

tive. The object was a series of vertical lines scratched

with a fine needle point through the opaque film of an old

dry plate negative supported nearly forty-six inches in front

of the objective. After this gigantic microscope was focused

so as to show the lines through the eye-piece, a plane was

found not far from the eye end of the actual telescope tube

in which was a central image of the electric arc with a series

of diffraction images on each side. These images could be

dealt with by means of diaphragms so as to vary the final

image seen through the eye-piece as one deals with the cor-

responding images [‘‘spectra”] at the back of the microscope

objective to produce changes in the final image of the ordi-

nary microscope.

The scratched lines in the latter experiment were about

one-thousandth of an inch broad and from one-hundredth to

one-sixtieth of an inch apart. The least of these measure-

ments is more than a few multiples of any wave length of

light. Since the publication of his original paper Professor

Abbe has changed his views in respect to the size of objects

to which the diffraction phenomena and the associated image

324 A. CLIFFORD MERCER :

changes are peculiar. He no longer holds that they are

peculiar to objects measuring less than a few multiples of a

wave length of light ; for he has seen them produced by

‘‘gratings of not more than forty lines to the inch,” seen

through a lens of twelve inches focus.

If the Abbe diffraction phenomena and associated image

changes can be experimentally demonstrated with a portrait

lens or a telescope objective, is it not probable that they can

be demonstrated with any projecting lens and, moreover, have

any explanatory relation to the formation of the visual image

in these cases that they have to the formation of the micro-

scopic visual image? Again, if a portrait lens and a tele-

scope objective behave in the same way as a microscope

objective in experimenting with these diffraction phenomena

and associated image changes, doesa reason based upon such

experiments exist for regarding microscopic vision as ‘‘ suz

generis” St

There are three ways in which the projection of an image

by alens may be studied: One based upon the electro-

magnetic theory of stresses; a second, the physical, based

upon the wave theory; and a third, the dioptric or geomet-

rical, based upon the propagation of light in straight lines

and the laws of reflection and refraction. The first has not

been sufficiently studied to serve our purpose. The second,

according to the Abbe theory, is the only one by which

microscopic vision can be fully explained. The third which

serves to explain the projection of images of macroscopic and

larger microscopic objects is inadequate, according to the

Abbe theory, to explain the projection of images of more

minute microscopic objects.

A mixed method, largely the third and in part the second,

is commonly used and is the ‘‘ geometrical optics” of Lord

Rayleigh and Professor Tait in the Encyclopedia Britannica.

Under ‘‘geometrical optics” Lord Rayleigh not only includes

‘‘conceptions of the wave theory,” but treats of ‘‘ aperture”

* Tue MICROSCOPE AND ITS REVELATIONS, Dallinger-Carpenter Edition, 1891, p. 64.

+ Ibzd., p. 62.

THE PRESIDENT’S ADDRESS. 325

and ‘‘resolving power.”* ‘‘Indeed,” Lord Rayleigh says, +

‘it is not to be denied that the too rigid separation of optics

into geometrical and physical has done a good deal of harm,

much that is essential to a proper comprehension of the sub-

ject having fallen between the two stools.” Under this inter-

pretation of geometrical optics the writer believes that the

projection of images of the more minute microscopic objects

can be fully explained and, moreover, that such an explanation

in some shape is a necessary part of a complete theory of the

formation of images by every projecting lens.

For a time our discussion can be simplified by getting rid

of the idea of the actual sizes of objects seen through the

microscope or the telescope. When objects and distances

between objects are measured not by linear units but by the

angles they subtend at the center of the objective, ‘‘ resolv-

ing power” in the microscope is seen to be the same as

‘‘separating power” in the telescope. Resolving power

increases with ‘‘twice the sine of half the angle of aperture”

of the microscope objective. Separating power increases

with the diameter of the telescope objective. But twice the

sine of half the angle of the aperture of a given lens is its

effective diameter. The same power, then, is required to

show as separate pictures the images of two points of detail

subtending an arc of one minute whether the actual distance

between the points be very little, measured on the stage of

the microscope, or very great measured among tthe stars.

Resolving power may be regarded as separating power

brought to bear upon an object near a microscope objective

and separating power as resolving power brought to bear on

an object a great distance from a telescope objective.

In Fig. 1, let 4d and B be isolated centers of motion of

equal intensity radiating yellow light. Let SV bea section

of a screen interrupting light from the points A and f. Let

the rays of light 4c and Bc be equalinlength. Letthe ray Ad

be shorter than the ray 4d by half a wave length of yellow

* ENCYCLOP#DIA Britannica, Ninth Edition, Vol. XVII., p. 806.

+ Ibid., p. 798.

326 A. CLIFFORD MERCER:

light, Ae a whole wave length shorter than Le, Af a wave

length and a half shorter than Lf, and Ag two wave lengths

shorter than Bg. Atc, e and g where whole waves of the

incident rays coincide crest with crest and trough with trough

the intensity of one ray is added to the other. At the inter-

mediate points @ and / where crests oppose troughs and

troughs oppose crests motion becomes null and darkness

results. The increased intensity at c, e and g is not limited

strictly to these points in the line SN but is spread out

upward and downward to a certain extent and then fades

into the intervals of darkness. This is because crests nearly

coincide with crests at first, when the difference in the

lengths of the uniting rays is still nearly a wave length or an

integral multiple af a wave length. But as waves fail more

and more to coincide crest with crest and trough with trough

and tend more and more to oppose troughs to crests and

crests to troughs, interference results in less and less motion

and consequently less and less light.

A g+

Fic. I.

The distances between the points of greatest intensity c, e

and g are seen to depend upon the wave length of yellow

light. If the centers A and B# radiated red light, with a

longer wave length, the distances between the points of

greatest intensity on the screen would be greater and the

upward and downward spreading of light would be more

THE PRESIDENT’S ADDRESS. 327

correspondingly. On the other hand, if the centers A and

B radiated blue or violet light, with a shorter wave length,

the distances between the points of greatest intensity would

be less and the upward and downward spreading of light

reduced correspondingly.

If the screen were nearer or farther from A and B, it

would present the same appearance with this exception ; that

the distances between the points c, d, e, fand g would vary

with the distance between the sources of light and the screen.

If the line S/V of the screen were longer, additional points of

darkness and light would appear above g and belowc. [In

this and the diagrams about to be used the wave length is

thousands of times longer than an actual wave length of

light ; so the distances between such points as c and d, orc

and ¢, are thousands of times too great, made so for purposes

of demonstration. |

In Fig. 2, let dBCDE be a section of the emitting surface

of a projecting iens. Let O be a self luminous object (or one

illuminated with a full cone of sub-stage light) subtending a

small angle, 6Cc, at the center of the lens. Let OA, OB,

OC, OD and OE£ be rays which radiate from a central isolated

point in the object O, pass through a first lens surface not

shown and reach the emitting lens surface AE. Let SV be

a section of a screen receiving the projected image of a

central isolated point in the object O. In addition to the

refracted primary rays Ag, Lg, Dg, Eg and the direct primary

ray Cg, other less intense secondary rays*—such as those

shown by broken lines—are also propagated from the lens to

the screen, the secondary rays having less intensity with

their obliquity to the primary ray from which they radiate.

Such radiating secondary rays originate at every emitting

point of the lens surface AF. Secondary rays from two

isolated points, as B and C, when interrupted by the screen

SV, would behave as behaved the radiating rays in Fig. 1.

The full aperture of the lens is AZ. Suppose this aper-

*For anaccount of the origin and behavior of secondary waves, or rays, the reader is

referred to Preston’s THEorY oF Licut, Chapters III, VII, VIII and IX.

328 A. CLIFFORD MERCER:

ture to be reduced one-half, the emitting surface AE reduced

to BD. . Thus the points of emission A and & are excluded

by this first supposition. Let 4, C and D be isolated points

of emission, & and PD being at opposite edges of the aperture.

Let the rays Bf and Dh be longer than the rays Cfand Ch

by half a given wave length. Let the rays Be and Dz have

the same length as the rays Ce and Cz. Let the ray 4z be

longer than the rays Cz and Dz by two wave lengths and the

ray De be longer than the rays Ce and Be by two wave

lengths. As a result, the points ec, g andzin the line SV

are illuminated and the points f and.% are dark. Spreading

of light occurs at 2; g sand z. lf the screen werevmaere

extended, additional points of light would be seen above eg,

and below z. What occurs in the line SV, one diameter of

the screen, occurs in all diameters. Consequently g becomes

THE PRESIDENT’S ADDRESS. 329

a disc of light with a fading peripheral zone while fand %

become a ring of darkness and e andz a ring of light. If the

screen were more extended, larger and concentric rings of

darkness and light would be added to the pattern. The

intensity of the smallest ring of light would be much less

than that of the center of the disc, and with increasing

diameter the intensity of each ring would rapidly diminish to

invisibility.

If, now, the object O be an unbroken surface and self

luminous (or illuminated with a full cone of sub-stage light),

lying between the dotted lines C and cC, then its diameter

would be made up of a line of luminous points each of which

would radiate light to the projecting lens as did the central

point we have considered. One ray from each point would

pass directly through the center of the lens and fall upon the

screen SV somewhere between the points f and #. Each of

these direct primary rays would at its point of emission C in

the lens surface BCD give origin to radiating secondary rays.

One ray also from each point would after refraction by the

lens leave the emitting surface at #@ and fall upon the screen

somewhere between the points f and #. Each of these

refracted primary rays would at its point of emission B give

origin to radiating secondary rays. So, also, corresponding

primary refracted rays would be emitted from J and fall upon

the screen between / and , each giving origin on emission

to similar radiating secondary rays. Then might Ce be

regarded as a secondary ray originated at C from a primary

ray in the path cCf, and Cz a secondary ray from a primary

ray in the path 4CZ; and e would now have the same relation

to f, andz to 4, as we saw a moment ago Ff, or 4, had to g.

fand # would now be bright ends of the image /% of the

diameter of the object O; and the points ¢ and-z would be

dark by interference, while spreading of light from / toward

e, and from # toward 7, would occur. This spreading of

light from / upward and from 4 downward results in elongat-

ing the image of the diameter of the object. [A perfect

dioptric image would be sharply brought to an end at f above

330 A. CLIFFORD MERCER:

and / below.] Were the screen S/V a little more extended

downward, a bright point would appear below z and would

have the same relation to # that we saw a moment ago z, or

e, had to g. Accorresponding point would appear above g, if

the screen were extended a little upward. What would be

true in the projection of an image of one diameter of an

object would be true in the projection of an image of every

other diameter. Consequently, the surface of the object O,

supposed to be round, would be projected on the screen S/V

as a disc having a diameter a little greater than /Z and not a

sharp but a fading, or fluffy, boundary. Were the object

a line and O between OC and cC its section, then the image

would be a band of which the diameter image already

described would be a section. Were the screen more

extended, the disc would have concentric rings about it, or

the band would be flanked above and below by parallel lines.

(See first the dots and lines a, 7 and gin Photo. 1, and then

the same dots and lines in Photo. 6.)

It will be observed that in the first instance (the projection

of an image of acentral isolated point) e and z were bright

and in the second (the projection of an unbroken surface)

dark. In either case the illumination or darkness was the

effect of the disturbance at e or z resulting from the union of

the wave motions of all the rays there incident. If in the

first instance all the points in the diameter BCD were simul-

taneously effective, the illumination at e would be the result

not only of the union of coincident crests and troughs of the

secondary rays Be, Ce and De, but also of a like union, pair

by pair, of one secondary ray from each succeeding point of

emission in the lens surface downward from B to C with one

secondary ray from each corresponding succeeding point of

emission downward from C to DY. The illumination at z

would be the result of a similar union of the secondary rays

Bi, Ci and Di and also the union, pair by pair, of secondary

rays from the points between / and C withsecondaryraysfrom .

points between C and DY. (A primary ray is indicated by an

unbroken line, as Cg or Bg ; a secondary ray of first intensity,

THE PRESIDENT’S ADDRESS. 331

by a broken line of long portions, as Bf or BA ; and asecondary

ray of second intensity, by a broken line of shorter portions,

as Be or Az.

If in the second instance all the points in the diameter

BCD were simultaneously effective, the darkness at e would

be the result not only of the union of Be, Ce and De, opposed

in phase, but also a like union, pair by pair, of one second-

ary ray from each succeeding point of emission in the lens

surface downward from 4 to C with one secondary ray from

each corresponding succeeding point of emission downward

from C to D. Darkness at z would be accounted for in asimilar

way. What would be true in this and the former instance in

one diameter would be true in all diameters of the same surface.

Each lens surface in an objective gives rise to secondary

rays and is also a reflecting as well as a refracting surface.

So the primary rays incident at the last surface of an objec-

tive are ray by ray the compounded resultants of the union

of direct, reflected and secondary rays (less energy by giving

rise to secondary rays and by reflection) at all previous trans-

mitting surfaces. The total result in a path leaving the last

surface is compounded wave motion which on being inter-

rupted by a screen unites with other resultant compounded

waves arriving by different paths at the same point in the

screen. But the primary rays in their paths through the

objective are affected essentially alike ; so that those which

leave any one point in an objective arrive at the image of

that point in the same phase. A primary ray determines the

phase of the secondary rays to which it gives origin at the

last surface of the objective. Thus the phase of the com-

pounded wave motion of the ray 4e is determined in the second

instance chiefly by the phase the primary ray 4 at the emit-

tine point 2; “the phase of Ce, chiefly by*that of Cf at Cs

and the phase of De, chiefly by that of Df at D.

Now let the full aperture AZ in Fig. 2 be effective. Let

an image of a central isolated point of the object O be pro-

jected by the lens upon the screen SV. By the doubling of

aperture, the lens not only receives additional and more

332 A, CLIFFORD MERCER:

oblique rays from the object, but has additional points of emis-

sion. OA is one of the additional and more oblique rays

from the object. A and &, at opposite edges of the

double aperture, are additional points of emission. After

refraction the ray OA takes the path Ag, which is evidently

longer than the path Ag taken by the ray OB after refraction.

Both these paths are longer than the path Cg taken by

the ray OC after transmission.

Let the arc gm be drawn with Ag asa radius; the arc g/,

with Bg as a radius; andthe arc gf, with Cg asaradius. If

the ¢ ends of the first two radii were swung upward in the

arcs gm and g/, the interrupting screen SV would shorten the

radius Ag more rapidly than it would the radius &g (rela-

tively as are the distances of the arcs gm and g/ from the

screen SV). If the g end of the radius Cg were swung

upward in the arc gf, it would have to be longer to reach the

screen. This addition in length to enable it to reach a given

point in the screen would be less than the shortening the

radius Ag or Ag would suffer if interrupted at the same point.

It becomes evident diagrammatically that were the g ends of

these radii swung upward in the described arcs, the difference

in length between the radii dg and Cg would amount to half

a wave length in a swing about half as great as the swing it

would be necessary to give the g ends of 4g and Cg to

make the latter differ in length by half a wave length. Asa

result, such darkness as the aperture 5D placed at f would, by

the double aperture AZ, be placed half way between g and/.

In a similar way, such illumination as the smaller aperture

placed at e would, by thelarger aperture, be placedatfi Ina

corresponding way, the spreading of light upward from g would

be reduced to half what it was with the half aperture. Sym-

metrical phenomena would occur below the axis of the lens.

What is true of one diameter of the screen is true of all its

diameters. Therefore, the image of a central isolated point

in an object is projected by a lens of given aperture as a disc

and concentric rings having diameters equal to half those of

the disc and rings in the image projected by a lens of half

‘

THE PRESIDENT’S ADDRESS. 333

the given aperture. Asimilar study of other apertures would

but add to this evidence showing that the interference or dif-

fraction pattern, disc and rings, is proportionally contracted

with every increase of aperture.

Not only have microscopists noticed in practice the direct

relation of aperture to resolution, but also the fact that

isolated lines or particles in an object appear broader through

an objective of small aperture and narrower through an

objective of large aperture. This narrowing effect of

increasing aperture is due to the contraction of the diffrac-

tion pattern. J/¢ zs easily understood that the projected image

discs of a series of close points in an object (or the projected

image bands of a series of close lines) might touch or over-

lap when projected by a lens of small aperture, and, on the

other hand, might be separated or resolved when projected by

a lens of sufficiently large aperture. The separating or

resolving power of the telescope is thus explained. The

same explanation has been applied, by inference at least,

to projecting lenses generally, not excluding the microscope.

Only Professor Abbe and his followers exclude the micro-

scope and claim that microscopic vision is ‘‘ sawz generis.”

Simple parallel experiments with the telescope and micro-

scope show that the actual effects of aperture in both instru-

ments are in harmony with the above explanation:

Experiment 1: The instrument used was a telescope

having an aperture of two inches and a half and a focus of

forty-three inches, standing twenty-seven feet from a window

inadarkenedroom. Outside the window was a mirror reflect-

ing light from a bright sky into the room. Of all the light

reflected from the mirror that only reached the telescope

which passed through two pinholes in a piece of black paper

supported in front of the mirror. The diameters of the pin-

holes were one-thirtieth and one-twentieth of an inch respec-

tively; and the distance between them, one-tenth of an inch.

The iris diaphragm of an Abbe sub-stage condenser was

supported centrally in a temporary mounting of wood fitting

into the hood of the objective.

334 A. CLIFFORD MERCER:

When the diameter of the iris opening was one-sixteenth

of an inch, the two pinholes appeared, when seen through the

telescope, as one dim hazy disc. When the diameter was one-

eighth of an inch, a smaller and more distinct disc was seen.

When the diameter was three-sixteenths of an inch, the disc

was still smaller, brighter and better defined—with a dim,

hazy overlapping disc becoming evident. When the diameter

was one-fourth-of an inch, the discs (now distinctly two)

were smaller, brighter and just separated. When the diameter

was three-eighths of an inch, both discs were brilliant and well

separated, their relative sizes and distance apart approaching

truth. When the diameter was one-half an inch, the picture

was more brilliant—the larger disc tending to appear star-

like with irradiation. With the full aperture of two inches

and a half irradiation was marked in both. During these

observations thin concentric circles of light were glimpsed.

Experiment 2: The instrument and all the conditions

excepting one remained the same. The exception was this:

in. the hood was fitted a piece of stiff black paper instead

of the iris diaphragm, the circular piece of paper allowing no

light to enter the objective except that which passed through

a slot corresponding with one of its diameters. Thus the

objective was made rectangular in shape with a narrow aper-

ture in one direction and a long, or wide, aperture in the other.

The piece of paper with its slot was turned about so that the

slot corresponded with various diameters of the hood. The

discs seen through the telescope appeared stretched out, as it

were, into lines always crossing at an angle of 90° the diam-

eter of the instrument corresponding with the slot. The

width of each line was determined by the long aperture; the

length, by the narrow aperture. A comparison of the width

of each line with its length showed the comparative effect of

the two apertures in contracting the diffraction pattern.

Experiment 3: The instrument used was a Powell and

Lealand microscope with a centering and focusing sub-stage.

The objective was a Zeiss ‘‘aa”,.having a focus of about I-

inch, and N. A. of .17. The eye-piece was usually a Powell

THE PRESIDENT’S ADDRESS. 335

and Lealand ‘‘compensating 20.” The sub-stage carried a

Powell and Lealand apochromatic condenser of {-inch focus,

and N. A. of about .9. At a distance of three feet in front

of the microscope the same pinholes used in the first two

experiments were arranged so as to allow only such light

from a lamp flame as passed through them to reach the mirror

of the microscope. The light reaching the mirror was

reflected through the sub-stage condenser to an aérial image

of the pinholes projected by the condenser in the plane of

the microscope stage.

The aérial image of the pinholes was the object observed

through the microscope. Seen with a small diaphragm open-

ing back of the objective the pinholes appeared as two discs

just touching one another. With larger openings the discs

became smaller, more brilliant and separated. The effects

of varying aperture (varied by means of diaphragm open-

ings back of the objective) in this experiment with the

microscope were the same as those seen in the first experi-

ment when aperture was varied by means of diaphragm open-

ings in front of the telescoe objective.

Experiment 4: The instrument and all the conditions

excepting one remained the same as in the third experiment.

Instead of the central opening in a diaphragm back of the

objective, a slot corresponding to one diameter was used.

The aperture of the objective thus became rectangular in

shape.

The image of the pinholes was observed. while the slot

was turned so as to lie successively in all diameters of the

instrument. The effects were the same as those seen when

the corresponding Experiment 2 was made with a telescope.

Before the diaphragm was placed back of the objective the

discs appeared as shown diagrammatically in Fig. 3 at aand 0.

Later, with the slot directed as shown at A, the image became

a line for each disc (a’ and 0’) with diffraction points at each

end, the latter not shown in the figure. With the slot

directed as shown at & the diffraction patterns overlapped

(2’’ and 6’). a’ and 0’ show resolution by wide aperture (the

336 A. CLIFFORD MERCER:

length of the rectangular aperture) ; and a’ and 6”, failure in

resolution by narrow aperture. Witha slot three times as

wide the lines a’ and 6’ become one-third as long; and a’’

and 6” did not overlap, but appeared as shown ata’” and 6/”,

Resolution in the last instance was affected by both aper-

tures, but to a greater degree by the longer.

a b’

FIG. 3.

Resolution and failure in resolution are also shown at (7

and D in Photo. 25, taken with a horizontal slot, and at 7

and D in Photo. 26 taken with the same slot placed verti-

cally, the object and other conditions in each case being the

same. In these two Photo’s are seen faint diffraction points

at the ends of some lines [well shown in the photomicrographs,

but not in the half-tone reproductions] and faint diffraction

lines flanking others, depending upon the direction of the slot.

Our geometrical and experimental study thus far suggests

the following:

A perfectly projected dioptric image [one free from defects

due to spherical and chromatic aberrations and diffraction]

would be point by point a correct picture of an object. But

as the images of points are not projected as points, but as

discs, a perfectly projected dioptric image is an impossibility.

Excluding spherical and chromatic aberrations, these discs (in

so much that they are larger than points) are due to aperture

diffraction effects. Aperture diffraction effects are contracted

with every increase of aperture. The essential object of

increasing aperture is to contract diffraction patterns, and thus

cause the projected image to approach as a picture as nearly as pos-

sible that which we can only imagine, never realize, a perfect

dioptric image. The more nearly the picture approaches in

character a dioptric image, the less will be the overlapping of

the projected images of details, the greater will be the

THE PRESIDENT’S ADDRESS. 227

separating or resolving power of the projecting lens, and the

better will be our idea of the object under observation.

This is illustrated by Photo’s 9 and 10. Photo. 9 was

taken with an aperture barely wide enough to resolve

the closer of a double series of lines cut through an opaque

film of silver. The bare resolution of the closer lines gives

usa poor idea of fine cuts in an opaque film. We need to

see the details of the edges of the lines and of appearances

between the lines (asin Photo. 10), requiring wider aperture in

various diameters, to get a better idea of cuts and imperfec-

tions inthe film. We need then wider and wider aperture to

resolve details of details, and wider and wider aperture still in

every diameter to resolve successively finer and finer details of

details (as long as they are present, or a practical limit to increase

of aperture 1s not reached). Thts ts accomplished by contract-

ing more and more the diffraction disc image of cach of the indt-

vidual points of which every object may be considered to be an

aggregation, be its form what it may. Not only does our study

thus far suggest the foregoing theory of microscopic vision,

one applicable to all projecting lenses, but calls attention to

the fact that one of the essential factors of the Abbe theory

is not always present; for the details of our self-luminous

aérial mucroscopic object originated no diffracted rays, although

the microscope objective projected and resolved in usual

fashion.

Suppose, fora moment, our aérial object originated dif-

fracted rays. As every path between the object and the

objective was occupied bya primary ray, diffracted rays could

have taken only the same paths. Starting from the same

points in the object they could have had no individuality ;

for each, diffracted from one primary ray, would have become,

at its very origin, a part of another primary ray leaving the

same point—just making up for the loss by the latter of a

corresponding diffracted ray given to the former. A similar

exchange of diffracted rays everywhere* in the cone would

*“ Everywhere” is not strictly true when a cone just fills an objective. Primary rays

toward and at the periphery would then lose rays diffracted outward beyond the limit of the

cone and would receive no diffracted rays in return, as there would be no primary rays out-

side the cone from which diffracted rays could originate.

338 A. CLIFFORD MERCER:

have resulted in primary rays not differing appreciably from

those which occupied the same paths between the object and

objective, diffraction not occurring. Such were the condi-

tions under which Photo’s 9 and 10 were taken. The irreg-

ular rectangular figure [the same as & in Photo. 1] is the

area of the source of light projected in the plane of the film

of silver, projected by a sub-stage condenser cone of light

of more than sufficient angle tosend primary rays along every

path between the object and the objective. Diffraction by

the cuts and imperfections in the film resulted in an inter-

change of diffracted rays, but no appreciable alteration in

the character of the primary rays, 2. e. diffracted rays from an

object lose individuality at their very origin when an objective ts

filled by a full cone of light from a sub-stage condenser. Under

second conditions then we find a factor essential to the Abbe

theory of microscopic vision is not necessary ; for Photo's 9

and 10 show the effects of different aperture notwithstanding dtf-

fraction by the details of the object was practically nullified by full

cone wlumination.

That rays diffracted by an object are practically nullified

by full cone illumination can be shown experimentally.

While the apparatus was arranged for taking Photo. 9,

the full cone of light from the sub-stage condenser was

reduced to a small axial pencil. A bit of white card was

held against the front of the objective. Each cut in the film

diffracted light, spreading obliquely away from the axial

pencil. The diffracted rays leaving different cuts and

becoming incident at any one particular point on the card

traveled paths of different lengths. Interference phenomena

occurred. Any pair of adjacent cuts had essentially the

same relation to the card that the two sources of light A and

B in Fig. 1 had to the screen SV. The result on the card

was a bright round spot of light (illuminated by the

axial pencil) flanked on either side by fainter repetitions of

the round spot corresponding in their manner of production

with e and g in Fig. 1. The fainter spots were formed

wholly by diffracted rays from the cuts. A full cone from

THE PRESIDENT’S ADDRESS. 339

the sub-stage condenser was then used again. Primary rays

once more traveled every path between the cuts and the card,

and engulfed, as it were, the diffracted rays. The card was

illuminated by one large circular spot, including and blotting

out all the previous picture.

Lord Rayleigh, writing of resolving power of optical

instruments in general, and of the telescope in particular,

says: ‘‘ The contraction of the diffraction pattern with

increase of aperture is of fundamental importance with refer-

ence to the resolving power of optical instruments” ™* ;

resolving power is ‘‘ proportional to the aperture, and inde-

pendent of focal length” +; and ‘‘ The theory of resolving

power is rather simpler when the aperture is rectangular

instead of circular, and when the subject of examination con-

sists of two or more light or dark lines parallel to one of the

sides of the aperture. Supposing this side to be vertical, we

may say that resolving power is zudependent of the vertical

aperture, and that a double line will be about on the point of

resolution when its components subtend an angle equal to

that subtended by the wave length of light at a distance

equal to the horizontal aperture.” { Lord Rayleigh § is also

authority forthe experimental result that, if for a rectangular

aperture under the conditions just quoted a round aperture be

substituted, the latter to have the same resolving power must

have a width or diameter about ten per cent greater. Sir

George Airy“ has found by calculation that under the

same conditions the width or diameter of a circular aper-

ture must be about twenty per cent greater. Here is disa-

greement as to the exact difference, but not as to the fact

that of two apertures of the same width or diameter, one rec-

tangular and the other round, the resolving power of the

rectangular aperture is greater.

We have dwelt upon the ‘‘ fundamental importance” of the

contraction of the diffraction pattern with increase of aper-

* ENCYCLOPEDIA BRITANNICA, ninth edition, Vol. XXIV, p. 430.

t Lézd., Vol. XVII, p. 807. $ [bzd.

S$ The Fournal of the Quekett Microscopical Club, March, 1895, p. 28 (Nelson).

§| /é72., p. 27 (Nelson).

340 A. CLIFFORD, MERCER:

ture with reference to the resolving power of the microscope,

and the fact that resolving power in this instrument is pro-

portional to its aperture. Your attention is now invited to

the other optical laws quoted, though not in their order of

quotation. ‘‘A double line will be about on the point of

resolution when its components subtend an angle equal to that

subtended by the wave length of light at a distance equal to

the horizontal aperture,” when aperture is rectangular and the

double line is parallel with the vertical sides. Now, suppose

BD in Fig. 2 to be the width of a rectangular aperture. By

comparing the lengths of lines we have already considered in

this diagram we find the arc vf is equal to two wave lengths

of light. AC is equal to 5D. Therefore, the angle AC7 is

the angle a wave length (half of the arc xp) subtends at a dis-

tance equal to the aperture BD. This angle on comparison

is found to be half as great as the angle Cc and fCh. Accord-

ingly, lines separated by an angular distance equal to half

that between the lines 6C and cC would be about on the point

of resolution by an aperture equal in width to BD.

The aperture BD* in Fig. 2 projects a central point inan

object as a disc having a diameter of which the radii extend

upward from ¢ half way toward / and downward from g half

way toward “. The diameter of this disc therefore subtends

at the center of the objective Ct half the angle fC4%, or half

the angle 6Cc, an angle equal to the angle AC7, or to the

angle subtended by a wave length at a distance equal to the

aperture. If a point in the object O at the crossing of the

line 6C be projected by the same aperture BD, its image will

be a disc with % as its center, and an upper radius extending

half way toward ¢ where it would about meet the lower end

of the diameter of the first disc. The two discs would about

touch. If a point in the object O at the crossing of the line

cC be projected by the same aperture, its image will be a disc

with fas its center, and a lower radius extending half way

toward ¢, where it would about meet the upper end of the

* Supposing the resolving power ineach diameter of the aperture be the same as that

of a rectangular aperture of equal width [also true, for simplicity, in previous use of Fig. 2].

+C, in Fig. 2, is both the center of the emitting surface and the center of the objective.

THE PRESIDENT’S ADDRESS. 341

diameter of the first disc. These three discs on the screen

about touching one another would be a picture of three points

in the object about to be resolved. The centers remaining

the same, lessening the diameter of the discs would result in

a picture made up of three discs not touching one another ;

and, consequently, the corresponding three points of detail

in the object would be resolved.

Now, let AZ be the width of a rectangular aperature. At

a distance equal to this double aperture a wave length, half

of 7p, would subtend the angle dZrv. The angle A&E; is evi-

dently equal tohalfthe angle dCr. Accordingly the resolving

power of the double aperture should be twice as great as

that of the aperture 5D (equal to AC). We have already

found [p. 332]thisto be true: that the image discs of points

have half the diameter when projected by this double aper-

ture (as compared with image discs projected by half that

aperture), and that, therefore, the resolving power is twice

as great. We thus find our diagram in harmony with

the law last quoted, supposing the aperture to be rec-

tangular.

As to the difference in resolving power of a rectangular

and round aperture: Lord Rayleigh, experimenting with the

telescope, found a round aperture should have a diameter a

little less than ten per cent greater than the width of a rec-

tangular aperture to give the same resolution; while Sir

George Airy, by calculation, found a round aperture should

have a diameter a little more than twenty per cent greater

than the width of a rectangular aperture to give the same

resolution. To determine which result is nearer right practi-

cally in reference to resolving power in the microscope, I ruled

the lines shown [not accurately reproduced] in Fig. 4; and

photographed aérial images of them by means of square and

round apertures. The lines were ruled on a Geneva Society

dividing engine [in the physical laboratory of a kind friend,

Professor EF. Haanel, of Syracuse University], ruled in or cut

through the opaque film of an Eastman gelatino-bromide lan-

tern plate, exposed [toa gas jet for a fewseconds], developed,

342 A. CLIFFORD MERCER:

fixed, washed and dried in the usual way. The numbers

indicate the distances between the lines in millimetres.

An aérial image of the lines was projected with a sub-

stage condenser of }-inch focus. This image in the plane of

the microscope stage was photographed with a Wales 13-inch

objective, and a Powell and Lealand ‘‘ compensating 20”

eye-piece. Photo. 11 was taken with a round aperture of

54 mm. ; Photo. 12, with a round aperture of 6 mm. ; and

Photo. 13, with a square aperture of 5 mm. (the sides being

parallel with the lines). An aperture of 55 mm. is ten per

cent greater, and an aperture of 6 mm. twenty per cent

greater, than an aperture of 5 mm. Then, according to

Lord Rayleigh, resolution should

be nearly the same in Photo’s II

and 13—atrifle better in Photo. ITI.

According to Sir George Airy, it

should be nearly the same in Photo’s

12 and 13—a trifle better in Photo.

13. [In Photo’s 11 and 13 the

group of lines marked .46 should

be shown barely resolved, resolu-

BiG: tion being slightly more evident in

Photo. 11. Lines marked .42 in Photo’s 11 and 13 should show

no resolution, while the same lines in Photo. 12 should be

shown resolved slightly better than are the lines . 46 in Photo.

13—-or resolved as well as the lines .g6 in Photo. II.

These differences shown in the photomicrographs are

hardly perceptible in the half-tone reproductions.] If the

widths of the alternating white and gray bands [the latter of

which should be black] under 7, in Photo. 11, be critically

compared with the corresponding bands in Photo's 12 and

13, it will be seen that the gray bands are broadest in Photo.

12, and of nearly the same breadths in Photo's 11 and 13.

Corresponding results were got in other photomicrographic

experiments.

It will be noticed that the closeness of the .46 mm. group

of lines is about ten per cent greater, and that of the .50

THE PRESIDENT’S ADDRESS. 343

mm. group about twenty per cent greater, than that of the

eo) mim: sroup: The closeness of the’ 92 (mm: gtoup

of lines is about ten per cent greater, and that of the 7.

mm. group about twenty per cent greater, than that of- the

.64mm. group. Such gradation in closeness made compari-

son of the results of photomicrographic experiments an easy

matter. The results were found to agree with Lord Ray-

leigh’s experiments and not with Sir George Airy’s calcu-

lation.

That resolving power is ‘‘independent of focal length”

when distances between details of objects are measured by

the angle they subtend at the center of the projecting lens

becomes evident on again studying Fig. 2. Suppose the

focal length of the lens, a little less than CO in the diagram,

to be only half as great, the screen SV remaining fixed.

Then the object to be projected on the screen would be

necessarily half as farfrom Cas Oisfrom C. Theround surface

O would require only half as great a diameter in the new posi-

tion to be projected to the same pattern on the screen, by the

same aperture. The lines of the diagram would have to be

changed only by shifting the O ends of OA, OL, OC, ODand

O£ to a point half way between O and Cto enable us to

use Fig. 2 for demonstrating the projection of a round object

having half the diameter of O by the lens having half the

focal length. The distance between the points in the lines

6C and cC touching the ends of the vertical diameter of O in

its new position would be half that between the points in the

same lines which touch the ends of the diameter in the present

position of O. Theangle subtended at C by the diameter of

O in its present position is 6Cc. This is the same angle that

O with half as great a diameter in the new position would

subtend at C.. Thus Fig. 2 would show resolving power to

be ‘‘independent of focal length” when measured by the

angle the distance between details subtends at the center of

the projecting lens. That this optical law applies to both the

telescope and the microscope [or to any other projecting lens],

is what one would expect, bearing in mind the fact that a

344 A. CLIFFORD MERCER :

telescope becomes a microscope by shortening sufficiently

the longer of its conjugate foci, and a microscope a tele-

scope by lengthening sufficiently the shorter of its conjugate

foci. }

While resolving power is independent of focal length when

measured by angles subtended-at the center of the projecting

lens, it is not independent of focal length when measured by

the actual distances between details subject to resolution.

This truth, set aside early in our study to simplify discussion,

may here be considered. We have justseen that Oin Fig. 2

would require only half as great a diameter to be pro-

jected to the same pattern on the screen SJ, if the lens had

half as great a focal length. Therefore, what was said in

a preceding paragraph [page 340] regarding the projection of

three points of detail in the object O would be true of three

points of detail half as far apart inthe smaller object, half

way between O and C, projected on the screen SW by a

lens of half as great a focal length. Then, in turn, neglect-

ing the angles subtended at the center of the projecting lens

by distances between the details of an object, we find that

resolving power relating to actual distances in an object

projected by the same aperture varies inversely with focal

length. With the same aperture, a }-inch objective would

resolve a series of lines half as far apart as would a

1-inch objective.

Photo. 15, of an aérial image of the ruling shown in Fig.

4, was taken with a 34-inch objective having an aperture of

2 mm.; and Photo. 16 of the same aérial image, with a I-inch

objective having an aperture of 2mm. _ Different eye-pieces

were used so as to get nearly the same amplification. The

relative closeness of the lines is shown in Fig. 4. Compare the

lines 7 unit apart in Photo. 15 with those 2 units apart in

Photo. 16. Compare these groups with the others in the two

Photo’s as to the comparative width of lines and the inter-

vening spaces. Of all the lines in Photo. 16 those 2 units

apart are, lines and interspaces, most like those 7 unit apart

in Photo. 15 (the interspaces between the lines 7.5 and 2 units

THE PRESIDENT’S ADDRESS. 345

apart in Photo. 15 being comparatively too wide). There is

additional evidence in the photomicrographs [not seen in

the half-tone reproductions], showing that with the same aper-

ture resolving power varies inversely with focal length when

distances between the details are subject to linear instead of

angular measurement.

The two expressions regarding the relations of resolving

power and focal length are, however, quite in harmony:

While resolving power measured by angles, at the center of

the projecting lens, subtended by details in an object is inde-

pendent of focal length, a shorter focal length (for instance)

necessitates a shorter distance between the object and the

objective. This results, on the one hand, in the same details

subtending at the center of the projecting lens a proportion-

ately greater angle ; or, onthe other hand, proportionately less

separated details subtending the same angle. In so far as

the details subtending the same angle are less separated as a

result of shorter focal length causing the object to approach

the objective, resolving power relating to actual distances in

the object is proportionately increased.

We have seen that the resolving power relating to actual

distances between the details of an object [and this is the

common meaning of resolving power in the microscope] is,

first, inversely proportional to the angle (at the center of the

projecting lens) a wave length of light subtends at a distance

equal to the aperture. Secondly, it is inversely proportional

to the focal length of the projecting lens. This means (refer-

ring again to Fig. 2) that by decreasing the angle AC7, or by

causing the object O to approach the lens, resolving power is

increased. Practically, there are limits to these two opera-

tions, and hence a limit to resolving power.

Let us see how these limits apply. It is practicable to

cause an object to so far approach a lens that the object all

but touches the glass, while the objective takes in from the

object a cone of light having an angle of very nearly 180°.

In such an instance a limit to resolving power is practically

reached. The object could not be nearer the objective ;

346 A. CLIFFORD MERCER:

and greater aperture could not be utilized, because the cone

of light from the object reaches approximately the highest

possible angular limit. But such a limit reached in the case

of a dry objective used with white light can be passed, and

is passed, in the case of an immersion objective, or a dry

objective used with light of shorter wave length. Consider

for a moment the use of monochromatic blue light of shorter

wave length: As with such light the arc rp in Fig. 2 would

be shorter, and the angle AC, proportionately less, resolving

power—varying inversely with this angle—would be greater.

Increase of resolving power with the use of blue light is

recognized in practice, particularly in photomicrography.

With the use of light of shorter wave length the angle

ACr is lessened by shortening the subtending arc yA. With

the use of immersion objectives this angle is lessened by

increasing AC, or the diameter of the emitting surface BD.

In Fig. 5, let O be a point in an object and Z the front

lens of a dry objective. Let @Od be a cone of light leaving

O and entering the lens Z. Suppose the ray.Qa to be

refracted by the surface vw so as to reach the surface xz at cand

the ray Od so as to reach the surface xz at

dad. The diameter of the emitting surface is

then cd. Now, suppose Oand the cone a0d

to be in a fluid having the same index of

refraction as the glass of the lens Z. Then

the rays Oa and O64 would suffer no change

in direction on entering the lens, Oa reach-

ing the surface rz at m and Od the same

surface at z. The diameter of the emit-

ting surface would now be increased by

Be the difference between cd and mn. The

greater the index of refraction of the lens Z the greater

would be the increase of aperture by homogeneous immersion.

Suppose thelens Z to havea higher index of refraction. Then

a cone of light in air of greater angle, vOzw, might after

refraction by the surface vw be emitted by the surface

dad. Now, suppose O and the cone of light vOvw be in a fluid

THE PRESIDENT’S ADDRESS. ZA 7.

having the same index of refraction as the glass of the lens Z,

with its higher refracting power. The rays Ovand Ow would

suffer no change in direction on entering the lens, Ov reach-

ing the surface rz at x and Ow the same surface at z. The

diameter of the emitting surface [or effective aperture] would

now be increased by the difference between cd and xz.

A few lenses have been made of glass of exceptionally

high refractive index, requiring a special homogeneous immer-

sion sub-stage condenser, stage slips and covers made of

special glass, as well as an immersion fluid of correspondingly

high refractive index. Such lenses and necessary accessories

made by Zeiss, of Jena, are very costly and very limited in

usefulness, while the gain in aperture is only about 60 per cent

(over dry apertures) as compared with the gain of about 50

percent in ordinary homogeneous immersion objectives.

The estimating of resolving power as to actual distances

in a microscopic object is a complicated matter ; for, in addi-

tion to aperture as a factor, we have found a consideration of

the effects of focus and immersion fluid must be included.

The meeting of this difficulty by Professor Abbe confer-

red a boon upon microscopists. By means of Professor

Abbe’s ‘‘numerical aperture” * [expressed by N. A.] it

becomes a comparatively easy matter to ascertain the resolv-

ing power of microscope objectives. Numerical aperture

tables, exhibiting the theoretical limit of resolving power

under different conditions of wave length, immersion fluid

and aperture, are now widely accessible, for instance in the

Dallinger-Carpenter edition of The Microscope and Its Reve-

lations, p. 84. These tables, however, are based upon the

Abbe theory and, therefore, exhibit too high a limit—that is

under conditions suitable for best microscopic vision [a mat-

ter to be considered later].

A study of the effects of projection by zonular apertures

is not only interesting but of practical importance ; because

* For an explanation of ‘‘ numerical aperture’’ the reader is referred to Chapter II in

the Dallinger-Carpenter edition of THr Microscope AND ITs REVELATIONS. In this paper

aperture means opening, or extent of opening measured by its diameter or breadth,

A. CLIFFORD MERCER :

348

Fig. 9.

o 7

iv i 4+ ae + ~~ ¢

ly a

Se ee

‘

— 4" —"

-+-

“om ary +! ay)

poe

aed

Vv +

THE PRESIDENT’S ADDRESS. 349

both objectives and sub-stage condensers are commonly

not aplanatic, different zones having different foci. The

effect of projection by one zone of an objective may be seen

with one focusing and that of projection by a different zone

with another focusing. The importance of having but one

focus for all zones of the objective [and of the sub-stage con-

denser which by having different foci for different zones

sends primary rays, at any one focusing, only to the one zone

in the objective corresponding to that which is at the time

operative in the sub-stage condenser] becomes evident on

studying Fig’s 6, 7, 8 and 9, and corresponding photo-

micrographs.

In Fig’s 6, 7 and 8, let VW be a section of a diaphragm

in contact with the emitting surface of a projecting lens.

Let X, Y and Z be three self-luminous points (or points illu-

minated by a full cone of sub-stage light) in one of the con-

jugate foci of the projecting lens, and a, z and g primary ray

images of X, Y and Z in the other of the conjugate foci. In

Fig. 6, the diaphragm )l’IV has two slots of which ¢ and 5 are

transverse sections ; in Fig. 7, two slots of which 2 and 3

are transverse sections ; and in Fig. 8, two slots of which

z and 3 are transverse sections. The distance between the

slots 4 and 5 is twice as great as the distance between the

slots 2 and 3, and four times as great as the distance between

the slots z and 3. The distance between XY and Y (and Y

and Z) is supposed to subtend a very small angle at the

center of the projecting lens. [The distance is thousands of

times the actual distance ; and, as in previous diagrams, the

wave length used is thousands of times too great. This is

necessary to enable us to deal with measurements great

enough.to be useful.] Each slot is supposed to uncover one

point of emission. Primary rays are indicated by unbroken

lines, and secondary rays by broken lines. The broken charac-

ter of the lines in any one of the diagrams increases with the

obliquity of the secondary ray to its primary ray. For instance,

4k and 4m in Fig. 6 are secondary rays from the primary ray

4i. The line zm is more oblique to ¢z than Zk is to 47; and

4m is more broken than Zé.

350 A. CLIFFORD MERCER :

In Fig. 8, each slot allows one primary ray to reach each of

the images a,z andg. The imagesa, z and gare notas perfect

as the diagram indicates ; for there would be to the right and

to the left of the points a, z and g such spreading of light as

we have before fully considered. At each slot in Fig. 8 a

primary ray gives rise to secondary rays. One secondary

ray from each slot reaches ¢, and one from each slot m. 4 [In

this, and Fig’s 6 and 7, secondary rays to the left of a and to

the right of g are not considered. They would take paths

symmetrical with the secondary rays in paths to the right of

a and to the left of g, respectively.] The secondary rays re

and 3e differ in length by half a wave length, are opposed i in

phase and interfere ; and eis dark. Correspondingly, 2 is

dark. Over a, e, z, mand qin Fig. 8 are plus and minus signs

indicating illumination and absence of illumination, corres-

ponding to the same signs in Fig’s 1 and 2

After studying Fig’s 1, 2 and 8, it is easily understood

how the emitting points 2 and 3, in Fig. 7 [twice as far apart

as z and 3 in Fig. 8] project images of YX, Y and Zat a, z

and g, with diffraction patterns extending to the right and left

of a, zand 4g, respectively, equal to half those projected under

the conditions of Fig. 8. Thus c is dark, the result of union

of secondary rays opposed in phase; while ¢ is illuminated, the

result of the union of secondary rays agreeing in phase. In

a similar way, g, &, m and 9, with their plus and minus signs,

are accounted for.

In Fig.*6, the diffraction pattern, indicated by the plus and

minus signs above the letters a, 4, c¢, d, e, f, g, 4 tfy eee

mt, n, 0, pand g and projected by emitting points ¢ and 5 [twice

as far apart as the emitting points 2 and 3 in Fig. 7], is also

easily accounted for in a manner similar to that in which

we have accounted for previous diffraction patterns.

Now let us suppose all the emitting points, 4, 2, 7, 37 and

5, in Fig’s 6, 7 and 8, to be simultaneously effective. The

patterns of Fig’s 6, 7 and 8 would unite. The result of the

union is imperfectly expressed in Fig. 9, where the plus and

minus values of the three diffraction patterns are brought

THE PRESIDENT’S ADDRESS. 351

together and added, asit were. Line / stands for the pattern

of emitting points z and 5 in Fig. 6; line //, for the pattern

of emitting points 2 and 3 in Fig. 7; line ///, for the pattern

of emitting points z and 3 in Fig. 8; and line /V, for the

picture which union of the three patterns tends to produce (or

the image of X, Yand Z the emitting points 4, 2, z, 3and 5,

simultaneously effective, tend to project). The plus signs

corresponding with the primary ray image a, z and g, rein-

force one another, while the plus and minus signs corres-

ponding to secondary ray interference phenomena tend to

nullify one another. Fig. 9 [incomplete and not accurate* ]

serves to express graphically the general truth that mul-

tiplying the number of effective slots, or zones, intensifies

the primary ray image, while diffraction phenomena tend to

disappear.

Of the diffraction patterns projected in Fig’s 6, 7 and 8,

that of Fig. 8 [line /// in Fig. 9] is nearest like that which

the five slots jointly tend to project. But the latter is much

more intense, and the spreading of light to the right and left

of a, zand gq is only one-fourth that in the former. The

latter approaches four times as near being a dioptric image.

If X, Y and Z were sections of self-luminous lines (paral-

lel with slots in the diaphragm V W), a, z and g would be

sections of primary ray image bands. In addition to the

bands a, z and g in Fig. 7 two diffraction lines, e and m,

would appear. In Fig. 6 would appear six diffraction lines,

c, e, g,k, mando. The actual number of lines to the inch

in the object would appear to be doubled, and half as far

* Some points not shown, or not shown accurately, in Fig. 9: The primary ray image

projected by five slots has a brightness greater than that projected by any two of the same

slots in the ratio of five to two [due to the actual increased amount of light leaving the lens

and reaching the image]. Again, when the five slots are simultaneously effective the diffrac-

tion phenomena of line /, Fig. 9, can occur but once, because of the five slots only two are

sufficiently far apart to project such a pattern; while the diffraction phenomena of lines /7

and /// are intensified by more than one inter-pairing of the five slots. Therefore the latter

patterns have more light, respectively, than the former. On the other hand, the diffraction

phenomena of line / are contracted laterally [as by a wide aperture] so as to be twice as

intense as the diffraction phenomena of line //, and four times as intense as those of line ///,

The intense thin diffraction phenomena of line / are likely to show under certain conditionsas

residua of opposing diffraction effects, even when the slots are made a continuous aperture

by cutting away the intervening bars—as is shown atc,¢ and g (corresponding to the same

letters in Fig. 6; in Photo. 29. Moreover, to Fig. g9 should be added another diffrac-

tion pattern projected as the effect of the inter-pairing of slots three times as far apart as

slots 7 and 3, which would present two equidistant plus phenomena between 7 and g, instead

of the three shown in Fig. 6.

352 A. CLIFFORD’ MERCER:

apart, in Fig. 7; and quadrupled, and one quarter as far apart,

in Fig. 6. If V Wwerea section of every diameter of the dia-

phragm, the slots 2 and 3, and g and 5, would become annular

orzonular. Then z in Fig. 7 would be surrounded by a diffrac-

tion ring of light of which ev would be the diameter. At e

this ring would touch a similar ring surrounding a, and at m

another similar ring surrounding g [dots and rings in the mid-

dle upper portion of Photo. 6]. In Fig. 6, 7 would be sur-

rounded by two rings having, respectively, the diameters gk

and em. Two similar rings would surround a and g. The

larger ring about z would touch the larger ring about a at e,

and the larger ring about g at m. If X, Y and Z were sec-

tions of self-luminous lines, each point in a line would be pro-

jected as a disc withconcentric rings. The discs would over-

lap in one direction to form a band, while the rings would

cut one another so as to emphasize tangential lines parallel

to the bands [see bands, semi-rings at their ends, and parallel

tangential lines between them, in several portions of

Photo. 6].

Experiment 5: The apparatus and its arrangement were

the same as in Experiment 3, with two exceptions. The

exceptions were: first, for the two pinholes were substituted

three pinholes (in line, about } mm. in diameter and 2 mm.

apart from center to center) and, near the pinholes, a group of

three parallel slits (about } mm. wide and 2 mm. apart middle

to middle) ; and, secondly, for the diaphragms with a single

opening used at the back of the objective were substituted

diaphragms with two slots. Images of the pinholes and slits

were projected by the sub-stage condenser, with full aper-

ture, in the plane of the microscope stage, where they became

essentially self-luminous aerial dots and lines. The dots

corresponded with the self-luminous points X, Y and Z in

Fig’s 6, 7 and 8. Diaphragms were made to correspond

with VW in the diagrams. The distance corresponding to

z-3 in Fig. 8 was I mm.; the distance 2-3 in Fig. 7, 2 mm.;

and the distance 4-5 in Fig. 6, 4mm. A fourth diaphragm

had five slots, 1 mm. apart, which would uncover five points of

THE PRESIDENT’S ADDRESS. ass

emission corresponding with 4, 2, 7, 3 and 5 in the diagrams.

The slots were equal in length.

. The picture of the dots and lines seen through the micro-

scope, with the full aperture, is shown in Photo. I as a, z and

g, and at a, z and g repeated at an angle of 90°. [When taking

the photomicrographs: an arc light and bull’s-eye lens were

substituted for the lamp ; between the pinholes and slits, in

a black card, and the sub-stage condenser was a blue light

filter ; the microscope tube was horizontaland the mirror was

not used.| The full aperture image shown in Photo. 1 is

nearest like the original object. Projected with five isolated

slots, the image shown in Photo. 5 differs more; while with

two isolated slots, the picture shown in Photo's 3 and 4 (cor-

responding with Fig’s 7 and 6, respectively) differs remark-

ably from the original object.

Photo's 1, 2, 3, 4 and 5 present a pictorial warning against

the use of tsolated zones [each behaving like two slots, in every

diameter|, often utilized unwittingly by the practical worker

[a result of imperfect correction of spherical aberration in

either the objective or sub-stage condenser], for if such simple

details as we have studied are changed in appearance so

remarkably, imagine what must be the corresponding changes

presented to an observer when studying complicated structures !

In taking Photo. I, an aperture of 10 mm. was used.

In taking Photo. 29, a continuous aperture of about 4 mm.

(just sufficiently wide to take in the emitting points zand 5 of

Fig. 6) was used. In the latter a faint diffraction pat-

tern, corresponding to that in Fig. 6, is seen partly atc, e

and g, and partly between z and g; while in Photo. 1 such

diffraction phenomena are absent. Great intensity of the

light used, or long exposure of the photographic plate, may

favor the projection of such a diffraction pattern as that seen

in Photo. 29 [residual—see footnote, p. 351].

This matter of intensity of light in relation to aperture is

worthy of little attention. If late in the day a microscope

be arranged so as to resolve an object, with deepening twi-

light the closest and presently the less close details disappear.

354 A. CLIFFORD MERCER:

Similar phenomena are met with in ordinary work as the

result of poorillumination. Onthe other hand, ‘‘ drowning”

with an excess of light [sometimes softened by using a blue

glass filter] is an effect commonly seen.

There is an intermediate intensity best for microscopic

vision. Bearing this in mind, if the intensity of the light in

primary ray image bands were to measure twenty units and

that of certain parallel diffraction lines one unit, the latter

being barely visible, illumination could be lessened ninety-five

per cent and still be sufficient to enable an observer to see

the primary ray image bands, while the diffraction lines

would be far too faint to be seen. On the other hand,

if the diffraction lines of one unit intensity [barely vis-

ible] were to be illuminated twenty times as _ brilliantly

to give them proper visual intensity, the primary ray

image bands would be twenty times too intense and might

suffer from ‘‘drowning” effects. The less the difference in

intensity between the primary ray image bands and diffrac-

tion lines, the more likely are diffraction phenomena to

obtrude themselves in a picture when the primary ray image

has proper visual intensity. The use of pairs of slots or

isolated zones, as compared with the use of continuous aper-

tures, lessens this difference in intensity and favors the

obtrusion of diffraction phenomena [compare c, e and ¢ in

Photo’s 4 and 29, the former taken with a pair of slots and

the latter with a continuous aperture ].

Experiment 6: The general arrangement of the apparatus

and the aérial object remained the same as in the last experi-

ment. But instead of rectangular slots, annular or zonular

slots were used at the back of the objective.

When an annular slot exposed emitting points in a circle

2 mm. in diameter, the image discs were surrounded by rings

of light having radii corresponding to ae, ze, zm and gm in

Fig. 7, and shown in the middle upper portion of Photo. 6.

When the annular slot exposed emitting points in a circle

4 mm. in diameter, the discs were surrounded by closer rings,

the radii of the smallest corresponding with ac, zg, z# and

THE PRESIDENT’S ADDRESS. 255

go, and the radii of the next larger with ae, ze, 2m and gm, in

Fig. 6, and imperfectly shown in the middle upper portion of

Photo. 7. The tangential union of diffraction rings between

the bands [overlapping discs] results in intense lines with

which, by comparison, the semi-rings at the ends of the

bands appear faint [better seen in Photo. 6]. Portions of

each ring are lost by interference in the intervals between the

bands and the tangential lines. The annular slot or zone

2mm. in diameter used in taking Photo. 6 was complete [a

coverglass elsewhere opaque with India ink], while that 4 mm.

in diameter used in taking Photo. 7 was broken [a stencil cut

out of black paper]. Of the diffraction rings in the photo-

micrographs, those projected with the former zone are con-

tinuous lines, while those projected with the latter are broken

—showing how sensitive the diffraction pattern is to modifi-

cations of aperture. The difference is imperfectly seen in

the half-tone reproductions.

In considering the photomicrographs up to this point we

have, for the most part, dealt with intensity in the one diam-

eter corresponding to the widths of the lines photographed.

Because the slots used had the same length, the intensity

depending upon such lengths remained the same notwith-

standing the changes experimentally made in the other

diameter. We shall now see that this is an imperfect view

of the matter. We have dwelt upon the facts that the diffrac-

tion pattern is contracted with every increase in diameter

and that this is true in all diameters. We know that with

circular lenses an area of diffracted light [a portion of a dif-

fraction ring or line] varies in extent inversely with the

square of its diameter or aperture. Therefore the light

intensity of such an area would vary directly with the square

of the aperture, provided the amount of light transmitted by

the objective were to remain the same. But the amount of

light transmitted by the objective increases with the square of

itsaperture. This means that, independently of the contrac-

tion of the diffraction pattern, an area of light in the pro-

jected image varies in intensity with the square of the

356 A. CLIFFORD MERCER:

aperture of the lens. Increase of aperture, then, adds to

the intensity of the diffraction pattern in two ways. The

increase of intensity gained in one way must be multiplied by

that gained in the other, to get the total increase. The result

may be expressed thus: The intensity of the diffraction

pattern varies with the square of the square of the aperture.

Experiment 7: The apparatus and conditions remained

the same’ as in the last experiment, excepting); =iesmeme

object was substituted an aérial image of a tiny pinhole ; and

for two or more slots back of the objective single slots were

substituted.

Photo. 8 is a double photomicrograph of the aérial object.

E had the first exposure of fifteen seconds, with a slot 2 mm.

wide. The aérial object was shifted very slightly to the

right. had an exposure of 1,215 seconds, with a slot I

mm. wide. Exposedon one plate, the two images had the same

treatment, in development, fixing and washing, and, there-

fore, could properly be compared as to their intensities.

[The triple broadening of the disc, by the lesser aperture, at

once attracts attention.| The exposures were so timed as to

show the first diffraction ring in each case, provided the

expression at the close of the preceding paragraph be true.

[The square of the square of the aperture I is 1. Thesquare

of ‘the: square of the. aperturei3 is: (3 x 3) x (3) 243),n0mrom

The exposures were as I to 81.|] In the negative it was

impossible to say that the two rings differed in intensity.

Unfortunately the half-tone process has failed to reproduce

the rings.

As a dioptric image would not be contracted by increase

of aperture, its intensity would increase with simply the

square of the aperture. Broad image areas, except at their

boundaries, also increase in intensity with simply the square

of the aperture. As such areas are made up of overlapping

images of points, of which the object may be considered an

aggregation, any increase of intensity due to contraction of

the overlapping discs within the boundary bands is balanced

by a decrease due to less overlapping.

THE PRESIDENT’S ADDRESS. 357

That boundary bands of image areas and images of isolated

lines are affected alike by aperture is shown in Photo’s

25 and 26. They were taken under the same conditions

present in taking Photo. I, excepting that, instead of full

aperture, a rectangular slot measuring 2 mm. by 6 mm. was

used back of the objective. In taking Photo. 25, the length

of the slot was horizontal ; in taking Photo. 26, vertical.

Careful measurements show that there is broadening of the

areas A and & with the lesser aperture in each case, and that

the broadening is such as can be accounted for by the widen-

ing of the boundary bands. The narrower the area, the

more important to the total breadth of. the area is the

broadening of the boundary bands. With small apertures

the visual pictures of finest particles and lines consist chiefly

of diffraction spreading. Such diffraction spreading not only

contracts with increasing aperture, but gains in intensity rap-

idly [with the square of the square of the aperture]. Thus,

increasing aperture narrows and intensifies most noticeably

the picture of finest details. Ina similar way, increasing aper-

ture causes diffraction spreading of boundaries of areas to

contract and to approach in intensity that of the area, as the

intensity of the former increases with the square of the aper-

ture, while that of the latter increases with the square of the

square of the aperture.

Does not a study of Photo’s 25 and 26 suggest a field for

thought regarding micrometry? For instance, recall the

disagreement of numerous careful workers who have meas-

ured blood corpuscles. Has one such worker recorded any

consideration of the aperture used ? Will not such a record

come to be regarded as an essential part of critical microm-

etry ?* While the percentage of error may not be great in

* A column might be added to numerical aperture tables to show what amount should be

deducted for each N. A., with, for instance, an amplification of one hundred diameters.

Astronomically, the diameter of, for instance, the sun’s true image is increased at each end

by half the diameter of a star disc; and, therefore,a measurement of the sun’s diameter

should be corrected for the aperture of the telescope used by subtracting the diameter of a

star disc measured, if measurable, by means of the same instrument, or one of the same

aperture. The uncertain [fading, not sharp] character of the visual boundaries of projected

images also contributes to the uncertainty of micrometry.

358 A. CLIFFORD MERCER :

the measurement of broad areas, it is likely to increase rapidly

as comparatively minuter objects and details are measured.

That a boundary of an area and an isolated line are affected

alike by aperture is again shown in Photo’s 23and24. The for-

mer, of an aérial image, was taken under the same conditions

under which Photo. I wastaken. The latter was taken under

the same conditions under which Photo. 2 was taken. The

right boundary is continuous with an isolated line, both of

which have been affected alike in Photo. 24 by aperture. A

study of the boundaries of the broader areas and of the dots

and lines in Photo’s 2, 3, 4 and 5, as compared with the same

in Photo. 1, furnishes more evidence to the same effect.

A boundary band is not exclusively affected by aperture.

Its next overlapping neighbor, and each succeeding band in

the light area, has the same diffraction pattern. The lines of

the diffraction patterns touch each other and produce the

step-like areas of graded tints outside the boundaries of the

light areas, seen in Photo. 5 [poorly shown in the reproduc-

tion]. Residua of these tints are also seen at the horizon-

tal boundaries of 4A in Photo. 25 and at the vertical boundaries

of A in Photo. 26.

The formation of these tints can be explained by means

_of Fig. 7. Suppose YZ and ZU to be lines in a light area

extending from Y7 to the right far beyond ZU, and XS

to be absent. The area may be regarded as made up of lines

parallel to Y7 touching one another. Images of the lines

would be projected as overlapping bands extending from z to

the left beyond a. Each successive band in the image to the

left of 2 would, if isolated, havea diffraction pattern indicated

by 2, m, oandg. Thus, m, o and g would be repeated for

each successive band. To the right of the right boundary

of the area projected to the left of z, the repetitions of g

just touching one another would extend from g to z, and the

repetitions of m from mto z. The tint between g and m

would be, for the most part, an intensity of light resulting

from the simultaneous effect [compounded wave motion] of the

repetitions of plus g and minus.o. The tint between mandz

THE PRESIDENT’S ADDRESS. 359

would be, for the most part, an intensity of light resulting from

the simultaneous effect of the repetitions of plus g, minus a,

plus#and minus’. Because the phenomena between m and z

are more intense than those between g and m, in inverse

relation to their obliquity, and because the phenomena

between g and # would be repeated and compounded with the

phenomena between mm and z in the overlapping of diffraction

patterns [the intensity of light between g and z being only

slightly increased by the overlapping of fainter portions of

the pattern which are not indicated in the figure but lie to the

right of g], the tint between g and # wbuld be considerably

less bright than the tint between m and z [and the next tint

to the right of g would be proportionately faint].

If the projected image of Y7 were fully shown by the pat-

tern extending from a to g, repetitions of the pattern to the

left of a would mutually and completely overlap one another,

and brightness would there be uniform. Between a and zg,

within the image of the bright area, overlapping would be

incomplete ; and between e and z, also within the image of

the bright area, less nearly complete. Asa result: a tint, less

bright than that of the image area to the left of a, would be

seen between a and ¢; and a tint of still less brightness,

between ¢andz. These tints within the image of the bright

area would be more intense than the tints outside the image

area, where overlapping becomes gradually less and finally

does not occur.

We are now prepared to reverse our explanation and show

how such boundary tints disappear when isolated slots are

replaced by a continuous aperture. Because boundary tints

depend upon the presence of diffraction patterns, the former

disappear with the disappearance of the latter. The right

boundary line of one tint is [a false image corresponding to

nothing in the object]. The repetition of this diffraction line

between 7 and z essentially constitutes the tint in that situa-

tion. Then, in order to eliminate the tint between m and Zz

from the picture, it is only necessary to eliminate the line

from the diffraction pattern.

360 A. CLIFFORD MERCER ;

Suppose every point of emission between 2 and 3 in Fig.

7 to be uncovered, the point z [see Fig. 8] would emit light

along a path to half a wave length longer than the path

3m [the path 2m being in the diagram a wave length longer

than 37]. A ray from each succeeding point between 2 and

Zz would take a path to m half a wave longer than a ray from

each succeeding corresponding point between z and 3 would

take to m. The raysinthe paths between 2 and zm being

longer than the rays between zm and 3m by half a wave

length, pair by pair, would be opposed in phase. The false

line # would be réplaced by darkness. Therefore dark-

ness would extend from half way between go on the right to

half way between £2 on the left. SX not being present ¢

would be a first diffraction line, produced by the union of

secondary rays in paths between 2g and zg with those in

paths between zg and 3g—the former being, pair by pair,

a wave length longer than the latter. If SX were present,

the primary ray image at g would be intensified by the union

with it of the same secondary rays. We thus see that all

emitting points in an aperture are important. By using them,

as compared with the use of isolated slots or zones, the picture

improves by eliminating from it false diffraction appearances.

Photo. 30 is of aérial lines taken with the same general

arrangement of apparatus. But for the sub-stage condenser

another—a Powell and Lealand achromatic of $-inch focus—

was substituted ; and for the objective, a Powell and Lealand

d-inch. At the back of the objective was placed a diaphragm

having three slots corresponding to 4, z and 5 in Fig’s 6 and

8, or the equivalent of a pair of slots corresponding in dis-

tance apart to 4 and 5 in Fig. 6, or a pair and a half of slots

corresponding in distance apart to 2 and 3 in Fig. 7. The

effect of such a combination is indicated in a general way by

an imaginary union of the lines / and // of Fig. 9, and is seen

in Photo. 30 at a, 2, 2, m and g. Plus eand plus m of the

first line unite with plus e and plus # of the second, in Fig.

g, to form the bright lines e and m of Photo. 30. Owing to

the contraction in the breadth of the plus effect represented

THE PRESIDENT’S ADDRESS. 361

by c, g, £ and o in the first line, the effect is 100 per cent

more intense than the minus effect of c, g, and o in the second

line when both are projected by two equal slots. But the

latter effect now projected by three slots has its intensity

increased by 50 per cent. This intensity, however, is still

50 per cent less than that of the former, projected by only

two slots [only two of the three being far enough apart].

Residua of plus effect corresponding to ¢, g, £ and o in the

first line give the corresponding faint lines seen in Photo. 30

(but indistinctly shown in the half-tone reproduction between

the lines a and ¢, e andz,z and m, and mand g). The same

pattern is better shown in the reproduction of Photo. 31.

The different effects studied by means of Fig’s 6, 7, 8 and

g, and shown in Photo’s 2, 3, 4 and 5, depend upon varying

the distances between the slots, the distance between and

Y, or Yand Z, remaining the same. The same effects may

be got in the inverse way by varying the distances between

the lines or details of an object, the distance between a given

pair of slots remaining the same, as may be seen in Photo. 4

in which projection by two slots, corresponding with gz and 5

in Fig. 6, causes the bands a, 7 and g of a primary ray image

to appear four times too numerous to theinch. To the right

of these bands is projected by the same slots a picture of

lines half as far apart as the lines a, z and g [compare the

two series of lines as shown in Photo. 1], which presents the

same appearance an image of a, z and g would present if

projected by two slots corresponding with 2 and 3 in Fig. 7.

In Photo’s 29 and 30 are seen somewhat different effects

due to varying distances between lines, the diaphragm back

of the objective remaining the same. The image to the right

of a in Photo. 30 was projected, as we have seen previously,

by three slots corresponding to 4, 7 and 5 in Fig’s 6 and 8.

The pattern just to the Jeft of @ is that which would be

projected by slots corresponding to 4 and 3, or 2 and 5,

in Fig’s 6 and 7. Compare this with the corresponding,

but residual, pattern under 7.5 in Photo. 29. The pattern

c, eand gin Photo. 29 is similar to that which would be pro-

362 A. CLIFFORD MERCER :

jected by slots g and 5 in Fig. 6, or that shown in Photo. 4.

The pattern under 7 in Photo. 29, with one faint diffraction

line between the bands, is similar to that which would be pro-

jected by slots 2 and 3 in Fig. 7, or that shown in Photo. 3

at e¢, m, a, 2 and g. The pattern to the left of the last,

barely showing. resolution, is similar to that which would

be projected by slots z and 3 in Fig. 8, or that shown in

Photo. 2 at a, z and g.

Although Photo. 29 shows patterns similar to those which

a pair of slots would project of lines different distances apart,

the picture was in reality taken by a continuous aperture—a

slot just wide enough to barely resolve the closest series of

lines shown as image bands in the first position [above and to

the left in Photo. 29], twice wide enough to resolve the series

shown in the second position, three times wide enough to

resolve the series shown in the third position, and four times

wide enough to resolve the series shown in the fourth posi-

tion. Between a, z and g in the fourth position are seen the

residua already mentioned corresponding to ¢, e and g of Fig.

6 or of Photo. 4. Between the image bands in the third posi-

tion are seen the residua of the corresponding broader lines

of Photo. 30. Between the image bands in the second posi-

tion are seen the residua of lines corresponding to e and mof

Fig: 7 or‘of Photos) 3.

Why do residua of light corresponding to diffraction lines

show in Photo. 29 and not in Photo 1? Partly because Photo.

29 had a relatively long exposure, Photo. 1 having only

sufficient exposure to enable the primary ray image to

properly affect the sensitized plate. The sensitized plate saw,

as it were, the projected image in Photo. I with a proper

intensity of light. In Photo. 29 the intensity was unneces-

sarily great, but not great enough to give the ‘‘drowning”

effect seen in Photo’s 6 and 7. If Photo. I had received

relatively the same exposure given Photo. 29, the greater

aperture effective in taking the former would have contracted

the pattern so that the diffraction lines could not have been

seen as separate from the primary ray bands without the

THE PRESIDENT’S ADDRESS. 363

aid of a pocket lens. This was found to be true by actual

test.

To what is the ‘‘drowning” effect seen in Photo’s 6 and

7 due? Inthe beginning of this paper the inverse relation

of the sizes of image discs, due to uncorrected spherical and

chromatic aberrations on the one hand and to aperture on

the other, was noted. In so-called achromatic objectives

these aberrations are at best incompletely corrected. In

apochromatics they are not perfectly eliminated. Residual

aberrations increase with aperture. Aberrant light, if iso-

lated, would give rise to aperture diffraction phenomena. It

would be reflected in ways similar to those we have studied

in the instance of primary ray light. The rays of each color

would project patterns peculiar to and depending upon their

respective wave lengths. Not isolated, aberrant rays unite

at lens surfaces with other rays leaving the same points, to

be compounded in resultant wave motion. Thus, aber-

rant light complicates wave motion. This results in a failure

on the part of the proper proportion of rays to fully nullify one

another and in residual diffraction phenomena spreading out

in the picture beyond the boundaries and in the interstices of

the primary ray image. Sufficiently brilliant illumination

gives such residual light a visible intensity. Aberrant reflec-

tions at numerous lens surfaces, any method of illuminating

an object which brings a zone of aperture into separate use,

and certain accidents of construction in the objective or sub-

stage condenser, result in an overspreading of light the inten-

sity of which increases with the brilliancy of illumination.

As a result of one or more of these several causes the inter-

vening spaces between the details of microscopic images

come to be occupied by more or less light. Under con-

ditions of ordinary usage it is not particularly noticeable.

But by excessive brilliancy of illumination or by excessive

aperture (relatively to poor correction of aberrations) increas-

ing residual aberrations, or by both, it may become visible or

with prolonged exposure affect the photographic plate. This

is evident in the results got in several negatives which were

364 A. CLIFFORD MERCER:

secured in attempting to photograph diffraction rings,

especially those of second and third intensity shown in

Photo. 7. [Such an explanation of ‘‘ drowning” effect sug-

gests an unrecognized factor—so far as the writer knows—in

the production of photographers’ ‘‘halation” which has

been thought to be due wholly to reflection from the back

surface of the negative plate or to the lateral spreading of

chemical action in the film, or both. On seeing the ‘‘ drown-

ing” effects in Photo’s 6 and 7, the photographer would say

they were due to ‘‘halation.”|

It was found that a thin cell with plate glass sides contain-

ing a deep blue solution of ammonio-sulphate of copper

placed anywhere back of the sub-stage condenser rids a visual

picture of much of the ‘‘drowning” effect by reducing the

intensity of illumination and eliminating some of the phe-

nomena due to other than blue wave lengths. Even with the

blue cell, which is less monochromatic with the increasing

intensity of the light it filters, long exposure gave the results

seen in Photo’s 6 and 7 [on double-coated ‘‘non-halation”

plates which gave better results than the ordinary plates also

tried].

Experiment 8: The apparatus was arranged as it was

when Photo’s 1 to 6 were taken. But instead of an aerial

image of bright lines and areas an aérial image of dark lines

and areas was photographed. Theresultsin Photo’s 19, 20, 21

and 22 correspond with those in Photo’s I, 2, 3 and 5, respect-

ively. Broadening of black bands in the image by narrow

aperture is seen in Photo. 20; the production of false diffrac-

tion lines (e and m), in Photo. 21; and the effect of using five

slots instead of two, in Photo. 22. In this experiment the

results are apparently analogous to those obtained with

bright linesasan object. But the black details are fainter than

the bright details in the corresponding photomicrographs.

This was more marked before Photo’s 19, 20, 21 and 22 were

intensified. [These alone of the photomicrographs submitted

were intensified to aid the half-tone plate makers.] On ~

comparing. broad areas the positive or bright effects tend to

THE PRESIDENT’S ADDRESS. 365

overbalance the negative effects. Bright areas in a dark field

appear too broad, due to spreading of light into the dark

field. Dark areas in a bright field appear too narrow,

due to spreading of light from the field into the dark areas.

This is seen in comparing A and 4 in Photo’s I and 2 with

A and A in Photo’s 19 and 20.

Photo. 23 is of an aérial image taken under the same con-

ditions under which Photo’s I and 19 were taken ; and Photo.

24, of the same aérial image taken under the conditions

under which Photo’s 2 and 20 were taken. Inthe upper part

of the picture is seen a negative band (a) ina bright area

and also a bright band (4) in a negative area. In Photo. 24

the false diffraction line duplicates of these two bands are

formed as though the fellow band and duplicates were absent.

The diffraction duplicates and the primary ray image bands

vie with each other for the same places in the picture, with a

result to the advantage of the bright line at every place.

[The half-tone reproductions show the negative effects imper-

fectly—hardly at all. |

Perhaps the best way to study the two series of photo-

micrographs compared above, and Photo's 23 and 24, is to

attend chiefly to the bright lines and areas: to consider the

positive effects of aperture in relation to the bright bound-

aries of bright areas, the bright boundaries of fields sur-

rounding dark areas, the bright bands and bright spaces

between dark bands ; and, on the other hand, to regard the

dark areas and bands as negative interruptions having only

corresponding interrupting effects in the projected image.

‘‘ Drowning” effect would tend to weaken the intensity of the

image of dark lines and particles, and to narrow images of

broad areas of black. Incritical micrometry it may be neces-

sary not only to have aregard to aperture, but also as to the

positive or negative character of the picture.

Experiment 9: The general arrangement of the appara-

tus remained unchanged. An aerial image of the lines of

Fig. 4 was projected by means of a Powell and Lealand

achromatic sub-stage condenser of $-inch focus, using dia-

366 A. CLIFFORD MERCER:

phragm opening ‘‘3.” The resulting aérial image was photo-

graphed with a Powell and Lealand $-inch objective and

2-inch eye-piece to get Photo. 27. Photo. 28 was then taken

after making but one change in the arrangement. Dia-

phragm opening ‘‘3” of the condenser was changed for

the smallest, ‘‘1.” Resolution fell off proportionately.

Several diffraction lines may be seen in Photo’s 27 and 28.

Photomicrographs might be produced to show that diffraction

phenomena parallel with those we have already studied occur

in images projected by the sub-stage condenser.

”

Early in this study a telescope lens was used as the objec-

tive of a gigantic microscope. In the present experiment a

microscope objective [for the sub-stage condenser is essen-

tially such] was used as that of a telescope. The two instru-

ments behaved alike. Moreover when a transparent object

resting upon the microscope stage is illuminated by an image

of the source of light projected in the plane of the object, it

appears that diffracted light may be a factor of illumination and

that a change in openings of the sub-stage diaphragm may

alter the character as well as the intensity of illumination.

[Compare, for a moment, Photo’s 27 and 28 with Fig. 4,

and note the difference between the original object, as

shown in Fig. 4, and the trebly-projected images. What a

falling off is to be seen in the final pictures! a result of

imperfection in lens projection. As we have double projec-

tion in ordinary practice with the microscope, we may believe

microscopic vision has nearly two-thirds of the imperfection

seen in Photo’s 27 and 28 as compared with Fig. 4 when

correspondingly high-power eye-pieces are used. |

Experiment 10: A telescope was arranged as in Experi-

ment 2. Instead of the paper diaphragm with a single slot,

diaphragms with two or more slots were used in the hood.

Emitting points uncovered by pairs of slots (or an isolated

zone of aperture) in a telescope behaved as we have seen

the corresponding apertures of a microscope objective behave

in the projection of diffracted phenomena.

Experiment 11: Fine and closely-ruled lines were

THE PRESIDENT’S ADDRESS. 367

observed while diaphragms with minute openings were held

between the lines and the eye. The conditions were varied

so as to convince one that the dioptric apparatus of the eye

projects diffraction phenomena parallel with those previously

studied in images projected by the telescope, microscope and

camera objectives. '

It isa matter of common observation that black articles look

smaller than white articles of the same size. A filament of

black carbon appears broader when incandescent in the electric

lamp. ‘The eye is not corrected for spherical and chromatic

aberrations. These aberrations cause light areas to appear

to encroach on dark ones. Our experimental study suggests

that diffraction effects are also a factor in the phenomenon.

The apparent spreading of light into darkness increases

with the intensity of the light. The brighter a star, the

larger it looks. Is not this phenomenon, ‘‘ irradiation,”

to the retina essentially what ‘‘halation” is to the sensitized

film of the photographic plate?

The optical imperfections of the eye and the effects of

its aperture, the pupil, contribute with those of the instru-

ments we have considered to project on the retina images

differing to a varying degree from the original object.

That the effect of aperture is important in the eye-piece

is shown by the influence variation in the size of the opening

in the eye-piece cap has on resolving power, both photomi-

crographically and visually. The field-lens is functionally a

part of the objective, the two projecting the image at the

diaphragm between the field-lens and eye-lens. The eye-lens

and the lens of the observer's eye are a projecting combina-

tion capable of projecting on the retina all the diffraction

phenomena we have found other lenses project.

Experiment 12: Photo. 32 shows the lines of an Abbe

test plate [the same shown, inverted, in Photo’s 9 and 10,

and described at page 337] taken when the last emitting sur-

face of the objective used was covered with a diaphragm

which had an eccentric opening I mm. wide and transmitted

only such rays as had been previously diffracted in the plane

368 A. CLIFFORD MERCER:

of the object by the lines cut through a film of silver. Photo.

33 was taken under the same conditions, excepting that

the eccentric opening was 2mm. wide. The effect of increase

of aperture, narrowing lines and favoring resolution, when

using only such rays as had been diffracted by the object

may be seen in the indistinct resolution in the upper half of

Photo. 33. This is more distinct in the photomicrograph.

Photo. 34 was taken under the same conditions as Photo. 32,

excepting that the slot I mm. wide transmitted central primary

rays. Photo. 35 was taken witha slot 2 mm. wide, half cen-

tral and half eccentric, transmitting through its central half

primary rays and through its eccentric half diffracted rays.

Since the half-tone reproductions illustrating this compara-

tive experiment were made, the experiment itself has been

repeated (visually) severaltimes. Asaresult the writer finds

that when Photo. 33 was taken the width of the slot was not

wholly filled with diffracted rays. This means that the effect-

zve aperture was a little less than 2 mm. wide. Aperture

beyond that which is utilized, or effective, contributes nothing

to resolving power. An accidentally lessened aperture is thus

shown to be responsible for the inferior resolution in Photo.

33 as compared with that in Photo. 35. Repetitions of the

experiment show that under parallel conditions the same

aperture gives the same resolution with either diffracted or

primary rays. In other words: Aperture affects diffracted rays

Jrom an object as tt does primary rays from an object.

Disregarding the accidental difference in resolution Photo’s

32 and 33 differ notably from Photo’s 34 and 35. Certain

negative imperfections, as breaks in a line, seen in the lower

pair are also to be seen in the upper, the pairs being alike in

this respect. Certain positive faults—scattered small splashes

of light, images of little irregular areas broken through the

silver film—seen in the lower pair are not to be seen in the

upper pair or are replaced in the upper pair by correspond-

ing negative faults. The positive faults in Photo’s 34 and

35 were projected by primary rays. No primary rays con-

tributed to the formation of the images seen in Photo’s 32

THE PRESIDENT’S ADDRESS. 369

and 33, but only diffracted rays of limited range as to obli-

quity. The position of the eccentric opening in the dia-

phragm determined the necessary obliquity of the rays which

could be transmitted. The closeness of the lines in the silver

film determined the obliquity of the diffracted rays which

reinforced one another [diffracted rays of other obliquities

leaving the lines in the silver film nullified one another by

interference]. The position of the eccentric opening in the

diaphragm was such as to transmit rays of the obliquity deter-

mined by the lines in the silver film. Certain positive faults

of various breadths in the silver film gave rise to diffracted

rays which reinforced one another at various obliquities out-

side the grasp of the eccentric opening in the diaphragm.

Such rays could not reach the picture. Their absence

resulted in negative ‘‘splashes” in Photo’s 32 and 33 corre-

sponding with certain positive ‘‘splashes” in Photo’s 34

and 35.

There are objects which may be satisfactorily illuminated

witha spot-lens or a sub-stage paraboloid—or by oblique light

obtained in any way—so that no direct rays reach the objec-

tive, but only those changed in direction as by refraction or

diffraction. Under such circumstances and in the case of a

uniformly fine structure, for instance, the cone of rays taking

paths to the objective might be exclusively diffracted light.

Thus the image would be projected wholly by diffracted rays

which on passing through the instrument would be affected

by aperture as we have seen primary rays are affected by

aperture. There would be one peculiarity about the inten-

sity of such light in the cone between the object and the

objective. The diffracted rays of greater intensity would be

nearer the periphery; because the primary rays, from which °

they would originate, would be outside the cone. The rays

would lose intensity with their nearness tothe axis. [Diffracted

rays originating from axial rays, as has been true in all pre-

vious instances cited, lose intensity in the opposite direction,

or with their obliquity to the axis. This difference in the

two kinds of cones may be shown to have some perceptible

370 A. CLIFFORD MERCER:

influence in the projected image.] The possibility of such

illumination is confined to the exhibition of objects observed

under low power objectives and belongs rather to the esthetic

than to the practical domain of microscopy.

If we consider opaque objects illuminated for microscopical

observation, all the rays between the object and objective

are indirect—by reflection. These indirect rays can travel

only in the paths already considered and can be affected in

no new way by aperture. Has it not become evident that

the diffraction of light by an object may be considered in

the same category with other changes in direction in incident

light produced by an object, as, for instance, those resulting

from reflection ?

In taking Photo. 10, between the object and objective

was used a cone which consisted of a full cone of primary

rays and a full cone of diffracted rays uniting at the origin of

the latter in the object to form a compounded resultant

full cone. In the case of a similar but coarser object,

illuminated by transmitted light, the primary rays might be

confined [first] to peripheral paths, or [second] to axial paths

in such a cone. In the [first] instance: there would be a

full cone of diffracted rays originated by the lines of the

coarser object which, if alone, would be affected in no new

way by aperture ; and in addition, primary rays uniting with

the peripheral diffracted rays. If the apertures at lens sur-

faces were not to be operative later, the only final result, ina

projected image, of the increased intensity in the periphery

of the cone would be a greater brilliancy of the picture.

But both the faint axial and the more intense peripheral rays

are affected by aperture, the latter rays tending to produce

the phenomena we have seen result from projection by a

zonular aperture. If the fainter axial rays were to have the

same focus, they would tend to correct the false diffraction

effects [obtruding zonular aperture effects] in the picture, by

giving origin at the emitting surface of the objective to

secondary rays, from secondary rays, tending to complete

the diffraction effects of a continuous full aperture. In

THE PRESIDENT’S ADDRESS. 371

the [second] instance: there would be the full cone of dif-

fracted rays; and in addition, primary rays uniting with the

axial diffracted rays. If the apertures at lens surfaces were

not to be operative later, the only final result in the projected

image of the increased intensity in the axial rays would be

a greater brilliancy of the picture. But both the faint peri-

pheral and the more intense axial rays are affected by aper-

ture, the latter rays tending to produce the effects we have seen

result from projection by a small circular aperture. If the

fainter zonular rays were to have the same focus, they would

tend to correct the defects [obtruding lesser aperture effects]

in the picture, by giving origin at the emitting surface of

the objective to secondary rays, from secondary rays, tend-

ing to complete the diffraction effects of a continuous full

aperture.

In practice it has been found that when the general con-

ditions of the [second] instance are made more specific,

when primary rays utilize a central circular surface of emts-

ston having a diameter equal to about three-fourths that of

the full aperture, conditions are favorable for best microscopic

viston, more favorable than when the whole of the last sur-

face is utilized by primary rays. Increased spherical aber-

ration due to increased utilization of aperture has been sup-

posed to explain why a full cone of primary rays does not

give so perfect a picture as the three-fourths cone. Mr. E.

M. Nelson* has shown that increased spherical aberration

can only in part explain the difference. A fuller explanation

for this at first sight contrary effect of a smaller aperture is

needed, and may be given, as follows :

When the horizontal width of a 5 mm. square aperture

resolved lines, as shown in Photo. 13, variation in the height

of the aperture was found to have no influence on resolving

power. A photomicrograph of the same aerial lines was

taken with an aperture height of 2 mm.; and another, with

a height of 8 mm. [the horizontal width remaining 5 mm].

* The Fournal of the Quekett Microscopical Club, March, 1895, p. 30.

372 A. CLIFFORD MERCER:

These photomicrographs only duplicated the result seen in

Photo. 13.

Let us examine circular and square apertures in relation

to the slots 4, 2, z, 3 and 5 of Fig’s 6, 7 and 8. In Fig. 10

the slots 4, 2, 7, 3 and 5 are shown bounded by full lines.

The diameter of the circle EH is three-fourths that of the

outer’ circle ABCD, Let the: area. within thejpcicele

ABCD represent the last emitting surface of an objective.

Let the object be a series of fine lines parallel with the length

of the slots. Let mst be a square aperture having a width

equal to the diameter of the full circular aperture of the

objective. The resolving power of a square aperture is about

ten per cent greater than that

of a circular aperture of the

same width or diameter. The

resolving power of the rec-

tangle ofgr is equal to that of

the square, so far as the hori-

zontal diameter of the objective

is concerned [and this is the

diameter upon which depends

prmete e

the resolution of the series of

lines constituting our present

object]. The other thirds of the square, the rectangular

apertures mnop and grst, have the same resolving power.

Now compare the portions of the slots within the middle

rectangular aperture ofgrv with those within nearly the same

area bounded by of above, gv below, and on the right and the left

by the boundaries of the full circular aperture. The portions

of slots 2, z and 3 are the same. Those of slots g and 5 are

nearly the same. If the upper and lower boundaries of the

two areas were nearer, the portions of the slots z and 5

included in the area would be still nearer alike. If the upper

and lower boundaries of the two areas were farther apart, the

portions of the slots z and 5 included in the areas would be

less alike. It becomes evident, then, that the portions of

the circular and rectangular apertures between the lines op

THE PRESIDENT’S ADDRESS. 373

and gv have nearly the same resolving power, and that, if the

lines of and gv were somewhat nearer, the included portions

of the two apertures would have practically the same resolv-

ing power.

Compare in a similar way the portions of the slots in the

upper third of the square with the portions of the slots the

corresponding part of the full circular aperture would utilize.

The corresponding part of the full circular aperture would

utilize almost the same portions of the slots 2, 7 and 3 that

are in the upper third of the square, but only comparatively

small parts of the portions of the slots g and 5 that are in

the same third of the square. What is true in this respect

of the upper parts of the square and the larger circle is also

true of the lower parts of the square and larger circle between

the lines gv and s¢. The diffraction effects of the upper part

of a full circular aperture are reinforced by the same effects

of the lower part. These united effects tend to be those of

an aperture corresponding to 2, z and 3? rather than of an

aperture corresponding to 4, 2,7, 3 and 5. Then portions, as

to vertical diameter, of the circular aperture tend to produce

the effects of a continuous aperture between and including

the slots 2 and 3 in Fig. 7; and another portion, the effects

of a continuous aperture between and including the slots

4 and 5 in Fig. 6. The result is intermediate aperture

effects. In other words, a study of Fig. 10 gives us an

explanation of the superiority in resolving power of a rectan-

gular as compared with a circular aperture, a superiority we

have already experimentally found to be about ten per cent.

Now, let the full cone of primary rays between the object

and the objective be reduced one-fourth, to a three-fourths

cone. The primary rays would then reach and fill the area

within the circle EFH. Slots zg and 5 would transmit no

primary rays. Their diffraction effects in the image would be

lost were it not for the fact that they would transmit diffracted

light, diffracted by the object. The lines of the object being

vertical, the diffracted light originated by them would be

spread out horizontally to the left and the right, not vertically,

374 A. CLIFFORD MERCER:

and would fill the horizontally opposite portions of the zone

lying between the circles E#H and ABCD. The portions of

the slots 2, z and 3 above the line wv and below the line wx

would not be utilized. The relative importance of slots 4

and 5 would be increased, by thus limiting the effect of aper-

ture to the area between the line zv above and the line wx

below. As a result, resolving power would be correspond-

ingly increased.

Were the cone between an object and the objective to be

so reduced that primary rays would reach and fill only a cir-

cular emitting surface having a diameter one-third of that of

full aperture, the effective aperture would be limited above by

the line of and below by the line gv. It would be approxi-

mately the equivalent of the rectangular aperture in relation

to the horizontal resolution of the vertical lines. The same or

more brilliant resolving power might be got by leaving the

cone between the object and objective full and using behind

the objective a diaphragm with a rectangular opening corre-

sponding with opgr. By narrowing sufficiently the vertical

width of the rectangular opening the resolving power might

be made equal to that of the square aperture. This is not

peculiar to the microscope objective. It is equally true of

the telescope objective.* It is possible, however, for the

accompanying loss of light from, for instance, faint double

stars, or from faint details of microscopic objects, to more

than counterbalance this increase of resolving power, visually

[long exposure photographically here having an advantage].

With a narrow rectangular aperture resolution effected by

the length of the aperture is limited to one diameter of an

object. When, on the other hand, the cone between an

* It would be advantageous for some purposes, if practicable, to construct a narrow and

rectangular astronomical telescope objective. Sucha lens would possess nearly ten per cent

more resolving power than a circular lens having a diameter equal to the length of the nar-

row lens, would be comparatively light in weight and require less strength of support. Or,

with the same extent of surface as the circular lens and about the same amount of glass and

weight, the length of the rectangular lens might be increased so as to transmit as much

light and have several times the resolving power. The’position of such a lens revolved about

its principal axis to get best resolution would indicate the direction of a line uniting the com-

ponents of a double star. In instances when the intensity of the light is unimportant, the

surface of such a lens might be cylindrical instead of spherical.

THE PRESIDENT’S ADDRESS. 375

object and the objective is reduced, the last emitting surface

of the objective remaining uncovered, vertical lines have a

selective power, as we have seen, utilizing horizontal aper-

ture. In a similar way horizontal lines utilize a vertical aper-

ture. Thus, any lines or details utilize appropriate aper-

ture. ‘‘Selective power,” if we may so call it, acts simul-

taneously and independently in different diameters, with a

possibility of exhibiting details generally in an object ten per

cent closer than the whole aperture filled with primary rays

can exhibit. This is not peculiar to the microscope objec-

tive. It is equally true of any other lens projecting an

image under parallel conditions.

As the Abbe theory requires a greatly reduced cone [for

without such a cone diffraction by the object is nullified

ances" spectra ”

sufficiently narrow cone may so utilize the aperture of an

are absent], and as we have seen that a

objective as to make it the equivalent of a rectangular aper-

ture in resolving power, we can account not only for the

greater resolution of a three-fourths cone compared with that

of a full cone, but for an excess of resolving power found in

the Abbe numerical aperture tables.

Mr. Nelson has studied four kinds of illumination in prac-

tical work and finds the actual resolving power to bein the

following order, the strongest first :

‘* Appearance at Back of Objective.

1. Peripheral annulus bright, } center dark.

Peripheral annulus dark, ? center bright.

. The whole dark (dark ground).

4. The whole bright (full cone).” *

Mr. Nelson finds this result not quite in harmony with

theory. The difficulty may be explained by means of Fig.

10.. The ‘‘ peripheral annulus bright” is shown as the zone

between the circles ABCD and EFH. In this zone are slots

4 and 5 and small portions of slots 2, 7 and 3. Because the

preponderance of effective aperture corresponds with slots z

and 5, the resolving power of the circular aperture in this

* The Fournal of the Quekett Microscopical Club, March, 1895, p. 34.

376 A. CLIFFORD MERCER:

instance approaches nearly that of a corresponding rectangu-

lar aperture. The ‘‘peripheral annulus dark, 2 center

bright,” has already been shown to have a resolving power

greater than that of the full circular aperture and less than

that of a corresponding rectangular aperture. Its resolving

power is less than that of No. 1 and more than that of No. 4

of Mr. Nelson’s list. On first thought, one would expect

No’s 3 and 4 to be equal in resolving power. We have

already noted [page 369] a peculiarity of a cone of light

leaving the object under the conditions of illumination present

in No. 3, z. e. it is more intense at the periphery. This

means that the effects of a peripheral zonular aperture are some-

what developed in No. 3. In No. 4 illumination is uniform

or less intense at the periphery. So No. 3 is the equivalent

of No. 4 plus a little of the effects of No. 1. Mr. Nelson’s

difficulty may be met thus without reference to the Abbe

theory.

Great reduction in the cone of primary rays between an

object and the objective in an attempt to make a round aperture

approximate in resolving power a rectangular aperture is not

advisable. The projected image loses dioptric intensity, by

the loss of primary rays, in proportion to such reduction.

Diffraction phenomena become more evident in the picture.

False appearances may obtrude themselves in the image

as a result of the rays diffracted by the object utilizing

isolated zones of the objective, especially when the isolated

zones of the objective have corresponding isolated foci.

Moreover, depth of focus—slight with a full cone of

primary rays—increases with reduction in the cone. A full

cone primary ray image is so nearly limited to a plane that it

comes into or goes out of focus immediately—not gradually,

while a narrow cone primary ray image responds to focusing

so gradually that it is difficult to say when focusing is correct.

With a full cone of primary rays of proper intensity we have

seen that diffraction patterns are contracted to a minimum

and may be visually absent. On the other hand, with a narrow

axial cone of primary rays from such an object as our last, dif-

THE PRESIDENT’S ADDRESS. 377

fraction patterns are broadened and multiple slot or zonular

diffraction effects—due to the diffracted light from the object

utilizing portions of the objective isolated from that utilized

by the axial pencil—become pronounced in the image. The

diffraction pattern may add force to a correct picture, or it

may add false appearances such as we have studied in con-

nection with Fig’s 6, 7, 8 and 9, and shown in Photo's 2, 3,

4and 5. It was noted that the diffraction pattern projected

in Fig. 1 would appear on the screen if the screen were

nearer or farther away from the sources of light. This

is equally true of zonular diffraction patterns. Above and

below the correct image plane are planes in which the zonular

patterns may be focused. This phenomenon with the uncer-

tainty of focusing correctly explains why an observer using

too narrow a cone of light in illuminating an object is likely

to see—by focusing isolated diffraction effects in other planes

than that in which the primary ray is projected—diffraction

‘« chosts,”

Arrange such an object as closely-ruled fine lines for

microscopic vision, illuminating it with a full or three-fourths

cone of light from a sub-stage condenser. The bands of the

primary ray image, all that can be seen, come into and go

out of focus immediately, without gradually appearing or

and not the correct image at all.

lingering. Now reduce illumination to a small axial cone.

It becomes difficult to determine when the primary ray image

is in focus. After the primary ray image isin focus, focusing

upward or downward causes the picture to give place to

imperfect repetitions of itself. Six or seven such repetitions,

each succeeding one becoming more unlike the primary ray

image, may be seen by focusing upward or downward. Such

repetitions are diffraction effects, ‘‘ ghosts” of the primary ray

image; and while one ‘‘ghost” is changing into another

more complicated diffraction patterns may be seen.

Theoretically and practically, then, we have seen that

advantageous reduction in a cone of light between an object and

the objective may be made only within a limit. Beyond such

alimtt counterbalancing evils are likely tobe met. The advts-

378 A. CLIFFORD MERCER:

able reduction in the case of a first-class objectivets found to

be from about one-fourth to one-third, never more than one-

half,* of the diameter of the cone. The diameter and angle

of the cone of light may be roughly determined and varied by

means of a sub-stage mirror, or critically determined and

varied by means of a sub-stage condenser of high quality,

z. e. made with the same care given to the making of the best

objective. Jf so much depends upon the cone of light between an

object and the objective, and this cone may be critically controlled

only by means of a sub-stage condenser of high quality, ts not

one impressed with the advisability of habitually using a

first-class aplanatic sub-stage condenser, and using tt intellt-

gently ?

Experiment 13: The general arrangement of the appa-

ratus was the same as

4 2 3 5 that used in taking

|: Photo’s I andi1g. An

opaque card, having a

cross-shaped hole cut

through it, was placed

Fig. 11.

against the bull’s eye

condenser—instead of the card and holes used in taking

Photo 1. An aérial image of the cross was projected in

the plane of the microscope stage by a I-inch objective,

arranged as a sub-stage condenser. This aerial image

was then observed through a 1r}-inch objective and a

2-inch Huyghenian eye-piece. Let Fig. 11 indicate dia-

gramatically the relative positions of the sub-stage con-

denser, aérial image and objective. The dotted line a shows

the position of the first lens of the sub-stage condenser,

and é the position of the second lens of the sub-stage con-

denser. Let c show the position of the first lens of the

objective, and d the position of the second or final lens of the

objective. Let ~ represent the Powell and Lealand sub-

stage diaphragm with circular opening ‘‘ 4

”

in use.) abet

* See the description of Fig.2in the frontispiece of the Dallinger-Carpenter edition of

THE MICROSCOPE AND ITS REVELATIONS.

THE PRESIDENT’S ADDRESS. 379

the angular lines YO X and W O U indicate the paths through

the lenses which the boundary rays of the light transmitted

by the diaphragm opening at 4 traveled. Experimentally

it was found that a circular opening 2 mm. in diameter in a

diaphragm capping the sub-stage condenser at 2, a circular

opening 3 mm. in diameter in a diaphragm capping the objec-

tive at 3, and a circular opening 5 mm. in diameter in a dia-

phragm placed back of the objective at 5 just permitted all

the rays transmitted by the diaphragm opening ‘‘4” to reach

the emitting surface at_d.

Then, without otherwise changing the arrangement, for

diaphragm 5 with its opening 5mm. in diameter was substi-

tuted diaphragm 8 [shown just back of 5] which had a zonular

opening and an opaque central portion 8 mm. in diameter.

Diaphragm 8 obstructed all the primary rays emitted by the

lensat d. The eye-piece was then removed. On looking at

the back of the objective the zone ed uncovered by dia-

phragm 8 was illuminated and remained illuminated even

when the circular opening at ¢ was changed to ‘‘1” of the

sub-stage diaphragm. The peripheral zone at the back of

the objective was illuminated by rays which must have been

separated from the direct axial rays at a previously operative

lens surface.

The 2-inch eye-piece was replaced. The eye-lens of the

eye-piece was removed. A I-inch objective was mounted in

the front board of an ordinary camera with the axis of the

objective coincident with that of the microscope tube. The

position of the camera with the objective was adjusted so as

to project an image of the cross on the ground-glass of the

camera with diaphragm 5 of Fig. 11 in place. The ground-

glass wasremoved. Initsstead wasexposed a sensitized plate.

The resulting photomicrograph is reproduced in Photo. 14.

Diaphragm 5 was then exchanged for diaphragm S. The

field-lens of the eye-piece projected an aérial image of the

annulus of light uncovered by the diaphragm 8. This aérial

image focused and photographed with the camera and its

I-inch objective is shown in Photo. 17. Immediately after-

380 A. CLIFFORD MERCER:

ward, while observing the image of the annulus on the

ground-glass as the camera with its I-inch objective was

pushed slowly towards the microscope, the annulus was seen

to shrink gradually and become the small cross shown in

Photo. 18, which is inverted as to the larger cross in Photo.

14. There can be no doubt, then, that the annulus was

illuminated by light which in some way was derived from the

aérial image of the cross projected in the plane of the stage,

light which must have left the direct axial rays at some point

in their paths. The inversion of the smaller image shows

that the eccentric rays while traveling paths through the

lenses were converged to at least one more focus than the

direct axial rays. Such additional convergence was neces-

sarily the result of at least two lens surfaces acting twice,

each acting as a reflecting as well as a refracting surface.

The exact paths taken by the eccentric rays have not been

traced. It is probable, however, that they were separated

from the direct axial pencil by internal and converging reflec-

tion at the emitting surface of the front lens of the objective

and returned to the front surface, thence to be reflected back

in an outward direction to and through the emitting surface

along eccentric paths towardtheannulus. Of what moment,

separately or as a factor in compounded wave motion, the

utilization of aperture by such faint aberrant rays is in micro-

scopic vision does not here concern us. The writer shows

that such rays are present chiefly because the same and simi-

lar rays have been regarded as factors in phenomena pre-

viously considered in our study [page 331 and page 363].

The Abbe ‘‘spectra” now invite.our attention. We

have found that they are not indispensable in the projection

of some of the images of microscopic vision. ‘‘ Spectra” are

images of an opening in the diaphragm of a sub-stage con-

denser, or of a source of light, formed above the objective in

the microscopic tube by diffracted rays originating in the

object. Can an image of an opening, or of a source of light,

formed in the microscope tube between the objective and the

field-lens of the eye-piece by diffracted rays have any influ-

THE PRESIDENT’S ADDRESS. 381

ence on the primary ray image of microscopic vision formed

between the two lenses of the eye-piece ? Two widely sepa-

rated images cannot be seen through the microscope at the

same time. In other words, such images cannot be united to

form a joint visual picture.

The plane in which the Abbe ‘‘spectra” are seen, when

present, is indicated by the dotted line HF in Fig. 2. The

position of one of these ‘‘spectra” is indicated at the point in

FF where the diffracted rays, dotted lines vz and we, cross.

The rays of light in the paths vz and we leave the same point

in the opening in the diaphragm of the sub-stage condenser

as part of a primary ray pencil, diverge to the lenses of the

sub-stage condenser, and are parallel on passing from the

sub-stage condenser to the object O. . As diffracted rays,

a’ vand ad’ w, they travel parallel paths to the lenses of the

objective. From the lenses of the objective they converge

to a focus ina plane //. As tothe object [now a’a’] the

two diffracted rays leave its opposite extremities. As to the

image of the object [now ze] they go to its opposite extremities.

Of the innumerable rays which leave one point in the opening

in the diaphragm and reach a corresponding point in the

image of the opening in the plane /¥ no two pass through a

common point in the object or arrive at a corresponding com-

mon point inthe image of the object. On the other hand,

each of the rays vz and we is but one of countless rays which

leave a common point in the object and reach a corresponding

common point in the image on the screen. Then the image

in the plane // of an opening in the diaphragm of the sub-

stage condenser is but an accident in the passage of light

from the object to the eye. Its influence as an image in

microscopic vision is nil. As an image it has no more to do

with the image of microscopic vision than the image of

Photo. 18 has to do with the image of Photo. 14, or than the

image of a window frame has to do with the image of a dis-

tant hillside, each brought separately into view by focusing a

telescope pointed through an open window.

When the cuts in a film of silver, shown in Photo’s 9 and

382 AY CLIFFORD” MERCER :

10, were illuminated with a small axial pencil and a card held

against the front lens of the objective one could see on the

card, as already described [page 338], a round spot of light

flanked on each side by fainter repetitions of the round spot.

On taking away the card, removing the eye-piece and looking

at the back of the objective one could see a picture similar to

that previously seen on the card, a bright round spot flanked

on either side by diffraction repetitions of the round spot, the

latter in spectrum colors. These were in this instance images

of an opening in the diaphragm of the sub-stage condenser,

projected by the objective in the plane FF of Fig. 2. The

lateral images in spectrum colors were the ‘‘spectra” of the

Abbe theory, corresponding in number with the faint lateral

repetitions of the round spot previously seen on thecard. In

explanation of Fig. I it was noted that light of different col-

ors, with correspondingly different wave lengths, would pro-

duce interference phenomena at slightly different points on

the screen. Ina similar way the pencils of diffracted light

brought to a focus in the plane /F have the rays of one color

united at points alittle removed from the points at which rays

of another color are united ; hence the spectrum colors in the

diffraction images and the name ‘‘spectra.” When the sub-

stage axial pencil was changed to a full cone of light from the

sub-stage condenser this picture inthe plane // was replaced

by a large circular area of light, an image of the largest open-

ing in the diaphragm of the sub-stage condenser, which

image included and obliterated every indication of the small

central spot and flanking ‘‘spectra.” No ‘‘spectra” are to

be seen back of the objective when an object is opaque and

appears bright under ordinary conditions of illumination with

reflected light. So sometimes the Abbe “ spectra” are present as

an accident of microscope projection and sometimes they are not.

Why do ‘‘spectra” when present appear to be so import-

ant? This apparent) importance of ‘‘spectra” |) maygeue

explained by means of Fig. 2. The ‘‘spectra” in the plane

FF, near the back of the objective, are so situated that when

’

a slotted diaphragm placed in the plane #F uncovers the

’

THE PRESIDENT’S ADDRESS. 383

‘«spectra,” under the conditions of Fig. 2,the same diaphragm

uncovers simultaneously the emitting points 4, 4, C, D and

E of the projecting lens. If now oneof the slots of such a

diaphragm be covered, one of the ‘‘spectra” disappears. A

corresponding change occurs in the projected image. But

this change is due to the loss of the slot and corresponding

emitting point of the projecting lens, and not to the loss of

one of the ‘‘spectra”; because, 7f the “ spectra” were absent,

in full cone wllumeination, covering the slot in the diaphragm would

produce the same change in the projected image.

Let us compare Fig’s 12 and 13. Fig. 12 shows paths

* certain primary rays travel from the source of light to the

eye. Fig. 13 shows chiefly the paths certain diffracted rays

of the Abbe theory travel from their origin in an object to the

eye. In both diagrams let CD be a sub-stage condenser ;

X Y Z, an object corresponding with the object in Fig’s 6, 7

and 8; 4A B, an objective; V W, a diaphragm having slots cor-

responding with [but supposed to be broader than] 4, 7 and 5

in Fig’s 6, 7 and 8; a,z and g, the primary ray image of

microscopic vision; / H,a positive eye-piece ; and £#, the posi-

tion of the opening in an eye-piece cap. Let Z, Zand LZ in

Fig. 12 be light, from a somewhat distant source, which

is focused at Y in the object by means of the sub-stage con-

denser. In Fig. 12 are shown above the object only such

rays as leave Y and pass through the emitting points of the

objective uncovered by slots 4, z and 5 in the diaphragm

VW. Such rays converge to a focus at z and then diverge

towards the eye-piece, by which they are rendered nearly

parallel so as to enable the eye to focus them upon the

retina. In Fig. 13 Lisa point in an opening of the dia-

phragm of a substage condenser, the diaphragm interrupting

all but a narrow axial pencil of rays from the source of light.

The primary rays leaving the point Z are converged by the

sub-stage condenser so as to be parallel. As parallel rays

they pass through the object to the objective. By the

objective they are focused in an image of Z at slot z. They

pass on each to a different point in the image a, z and g.

CLIFFORD

MERCER:

From the image a, 7 and g

they pass to and through the

eye-piece, by which they are

focused in a second image

of Z at & in the opening of

the eye-piece cap. From

the image at & they diverge

to such a degree as to make

it zmpossible for the eye to focus

them upon the retina at the

same time the rays shown in

Fig. 12 are focused upon the

retina. The diffracted rays

indicated by dotted lines

have their origin in the

plane of the object, and

take such paths toward the

objective as they would have

taken if they had been pri-

mary rays starting from the

points 7 and 7 in the open-

ing in the diaphragm of the

sub-stage condenser. The

diffracted rays travel paths

above the object similar to

those just now described,

and they fail to find a focus

upon the retina for the same

reason that the rays just now

described fail to find a focus

upon the retina. At slots 4

and 5 the diffracted rays

form ‘‘ spectra.”

In Fig. 12, countless pri-

mary rays from Y are now

supposed to pass through the

slots 4, z and 5 to form an

THE PRESIDENT’S ADDRESS. 385

image of Yatz. In Fig. 13, of the innumerable rays passing

through the diaphragm VW, three only—one primary ray pass-

ing through the slot 7, one ray diffracted by the object and

passing through slot 4, and one ray diffracted by the object and

passing through slot 5—contribute to the projection of the

image of Yatz. In Fig. 12, a and g would be projected as

images of Z and X as z the image of Y is projected. In Fig.

13, the projection of the images a and g is indicated as being

similar to the projection of the image z in the same diagram.

Of the rays forming the image of the point Z at the slot 7 in

Fig. 13, one ray leaves XY and goes to the image of X at g,

one ray leaves Y and goes to the image of Y at z, and one ray

leaves Z and goes to the image of Z at a. We see, then, by

means of the diagrams that the image of the point Z at slot 7

in Fig. 13 is but an accident in the passage of light from the

object to the image of microscopic vision, a, z and g. The

‘“spectra” formed at slots z and 5 in Fig. 13 are also seen to

be but similar accidents in the passage of diffracted light from

the object to the image of microscopic vision, a, z and g.

In addition to the image a, z and g in Figs. 12 and 13,

there is projected a diffraction pattern, the union of the

patterns indicated in lines 7 and // in Fig. 9, and shown in

Photo’s 30 and 31, as the result of slots 4, z and 5 uncover-

ing isolated portions of aperture. Suppose now that the

diaphragm V VW in Fig. 13 be removed. The primary rays

and the diffracted rays would still travel the same paths.

The same isolated portions of aperture would be utilized.

The image and diffraction patterns of microscopic vision

would be the same. Suppose, on the other hand, that the

diaphragm VW in Fig. 12 be removed. Such rays of the

full cone CYD as were previously interrupted by the dia-

phragm /’W would now pass on to the image of microscopic

vision, a, z and g. Every point in the emitting surface of

the objective would be effective. The diffraction pattern

previously seen would not be present, except possibly as

residua—such as may be seen between a and z, or z and g,

in Photo. 29.

386 A. CLIFFORD MERCER:

Instead of using the word ‘‘spectra” as synonymous with

images of an opening in the diaphragm of a sub-stage con-

denser projected in spectrum colors, let it be for a moment

synonymous with rays diffracted from the object destined to

reach one of the ‘‘spectra.” Such rays would contribute to

the projection of an image of an object just as primary rays

would if the latter traveled the same paths. Both kinds of rays

would form accidental images back of the objective of an open-

ing in the diaphragm of a sub-stage condenser, or of a source

of light under other but similar conditions. Neither kind of rays

would have anything to do with the diffraction phenomena

added to the dioptric image of an object were it not for aper-

ture being effective in the ways we have previously studied.

We have seen that the rays contributing directly tothe diffrac-

tion phenomena added to a dioptric image are secondary rays

originating at the emitting surface of the objective. That

such secondary rays do not have their origin in the object

may be shown by means of Fig. 7. At mis a bright point

in a diffraction pattern illuminated by rays which, if they

had their origin in the object, would necessarily leave—to

finally reach m in the image—a corresponding bright spot

in the object half way between X and Y, where there ts

no such bright point.

When the axial illuminating pencil is narrow and the Abbe

‘“spectra” are separated by well-marked intervals of dark-

ness, the Abbe theory ignores the emitting surface of the

objective corresponding with the intervals of darkness [g—7

and 7—5 in Fig 13]. In harmony with this partial neglect of

aperture, resolution in the Abbe theory may be said to

increase by jumps. So long as a central image of the source

of light alone is to be seen at the back of the objective [at

slot z in Fig. 13] resolution is not present. The aperture may

be increased without change in the contraction of the diffrac-

tion pattern, and in accompanying resolution, so long as the

central image alone is to be seen at the back of the objective.

But the moment the increase in aperture is sufficient to

uncover, or admit, one flanking spectrum image [at slot 4, or

THE PRESIDENT’S ADDRESS. 387

slot 5, in Fig. 13] resolution is present. With greater

increase in aperture no improvement in the picture as to the

contraction of the diffraction pattern, and as to accompanying

resolution, is to be seen until another spectrum image is

uncovered, or admitted.

On the other hand, with full cone illumination, resolution

increases continuously, and not by jumps or by periodic

accessions. The portions of aperture neglected in the Abbe

theory, those corresponding with the Abbe intervals of dark-

ness or the portions of the emitting surface of A 4 in Fig. 12

uncovered by removing the diaphragm lV W, are effective in

full cone illumination. They contribute in proportion to their

breadth, radially from the principal axis, to the contraction

of diffraction patterns. And thus they may resolve addi-

tional finer details [Experiment 14, below] in an object, or

increase the distinctness of the resolution of details already

resolved. Periodic accessions to resolving power are only

observed when the particular conditions necessary tothe Abbe

theory, or similar conditions, are present. Again, then, we

find the Abbe theory is unsatisfactory. On the other hand,

the general explanation of resolving power in optical instru-

ments is here applicable and satisfactory.

Experiment 14: A microscope was arranged to exhibit

the lines shown in Photo’s 10 and 35. For the optical part

of a Powell and Lealand sub-stage condenser was substituted a

Powell and Lealand I-inch objective. A Powell and Lealand

3-inch objective and a Powell and Lealand ‘‘ 10 compensat-

ing” eye-piece were used. A diaphragm with an opening

IO mm. in diameter was placed at the back of the objective.

The revolving diaphragm of the sub-stage condenser was

turned so as to bring opening ‘‘1” into use. The closer

lines of the test-plate were resolved. On removing the eye-

piece and looking at the back of the objective, a central

image of the opening in the diaphragm of the sub-stage con-

denser was seen flanked on each side at the limit of the aper-

_ture by about half of an Abbe spectrum image. The more

distant halves of the ‘‘spectra” were just outside the limit of

the aperture and could not be seen.

388 A. CLIFFORD’ MERCER:

Then, for the diaphragm with an opening 10 mm. in

diameter, at the back of the objective, was substituted a dia-

phragm having an opening 6 mm. in diameter. The latter

just covered both halves of the two flanking ‘‘ spectra,”

and left on each side of the central image a breadth of dark-

ness corresponding with one portion of the aperture neglected

inthe Abbe theory. On replacing the eye-piece and again

looking at the test-plate, the closer lines could not be seen.

Resolution failed, because under the conditions present the

Abbe theory requires for resolution the admission, by the dia-

phragm at the back of the objective, of at least a part of one

spectrum image in addition to the central image of the open-

ing in the diaphragm of the sub-stage condenser.

Again the eye-piece was removed. The diaphragm ofthe

sub-stage condenser was turned so as to bring opening ‘‘3”

into use. This change caused the central image seen at the

back of the objective to increase in size until it filled the

opening 6 mm. in diameter in the diaphragm at the back of the

objective. On replacing the eye-piece and looking at the

test-plate once more, the closer lines were seen. Resolution

returned as a result of the additional light from the larger

opening in the diaphragm of the sub-stage condenser reaching |

and utilizing the portions of aperture which were previously

dark under the conditions necessary to the Abbe theory.

Our study of the Abbe ‘‘spectra” directs our attention to

a relation existing between certain emitting points of a pro-

jecting lens, as Din Fig. 2, and the obliquity of rays diffracted

by an object, as the obliquity of a/v and @’w inthe same dia-

gram. If the extremities of the object O, between the lines

6C andcC, were points of light in two isolated point-like

holes in an opaque film of silver, the distance between them

would measure a little more than a wave length of light,

alittle more than x A. Suppose the two holes were changed in

position so that the upper one would correspond with a’ and

the lower one with the center of O. Let a similar hole, a’, be

placed as far below the center of O as a’ is above the center

of O. The object would then be three holes, with a distance

THE PRESIDENT’S ADDRESS. 389

between the center of O and @’ equal to that between the cen-

ter of Oand a’.. Let parallel rays from the left be incident

perpendicularly on the silver filmin the plane a’d’. Primary

rays passing directly through the holes towards C would be

parallel to or in the principal axis of the objective. Then

a'v, OD and a@’w would be diffracted rays. The refaction

of these rays by anterior lens surfaces between O and the

emitting surface A 6 C DE is not indicated. Ifthe anterior

lens surfaces were present and refraction shown, the three

parallel diffracted rays, a’ v, OD and a@’w, would have an

obliquity of nearly 90° to the principal axis of the lens, in the

case of a dry objective.

If the distance between the point-like holes subject to

resolution were just equal to one wave length, the obliquity

of the first effective diffracted rays leaving the object would

be just 90° to the principal axis of the objective. If the dis-

tance were equal to two wave lengths, the obliquity of the

first effective diffracted rays would be 30° to the principal

axis ; and then a second pencil of diffracted rays would be

effective at an obliquity of 90° to the principal axis. If the

distance were equal to three wave lengths, the obliquity of

the first effective diffracted rays would be 19° 28’; and then

a second pencil of diffracted rays would be effective at an

obliquity of 41° 46’; and then, also, athird pencil of diffracted

rays would be effective at 90°. With increasing distance

between the point-like holes subject to resolution an increas-

ing number of effective diffraction pencils of light would leave

the object at obliquities of less than 90° to the principal

axis of the objective, would pass through the objective,

and would be emitted at points in the surface between

Cand PD, or at points between C and &. If, on the other

hand, the distance between the point-like holes were less

than a wave length, and illumination were to remain axial,

no effective diffracted rays would leave the object. All

the diffracted rays about to leave the object would interfere

one with another. Corresponding darkness would result at

the front and emitting surfaces of the objective and in the

390 A. CLIFFORD MERCER :

plane FF. Only the point C of the emitting surface would

be effective. Only the primary ray axial image of the open-

ing inthe diaphragm of the sub-stage condenser would be

projected in the plane FF. The angles of obliquity* of

effective diffracted rays, to the principal axis of the objective,

determined by the distances between the points of detail

in an object are associated with certain points in the emitting

surface of an objective, such as those indicated in Fig. 2, ina

way similar to that in which they are associated with the

Abbe ‘‘spectra.”

In our study of aperture thus far we have had in mind illumi-

nation from a source of light situated in the principal axis

of the projecting lens. Only for exceptional purposes, and

only by those skilled in the manipulation of the microscope

and in the interpretation of diffraction phenomena, should

illumination from a source of light situated in a secondary,

axis of the objective be used. In all ordinary work the

mirror or the sub-stage condenser should be placed centrally, -

the center of the mirror or the axis of the condenser coinciding

with the principal axis of the objective. . However, under

proper circumstances the resolving power of an objective

may be about doubled by using sufficiently oblique illumi-

nation from a source of light in a secondary axis of the

objective. Let O Bin Fig. 2 be a primary ray from a small

source of light situated in a secondary axis of the dry lens

of nearly 1.00 N. A., or nearly 180° in air, passing directly

through a point-like hole at the center of O in the film

of silver. Suppose parallel incident primary rays pass

through similar holes at a’ and d@. Such primary rays

would leave the object at an obliquity of nearly 90° to the

principal axis of the objective, if the anterior lens surfaces

were present and refraction shown. As the first effective

diffracted rays would leave the holes at an obliquity of

nearly 90° to the direct primary rays the diffracted rays

would take paths in the direction O C. Only about half

* The English translation of THE Microscope IN THEORY AND PRACTICE, by Professors

Naegeli and Schwendener, p. 230.

THE PRESIDENT’S ADDRESS. 301

the objective would be utilized. Thus we see that the

obliquity of the first effective diffracted rays might have

been twice as great, or double the effective aperture might

have been utilized, or the holes in the film of silver might

have been half as far apart.

If the holes had been half as far apart, the direct primary

rays taking the same paths, the first effective diffracted rays

would have had an obliquity of nearly 180° to the direct

primary rays.* The direct primary rays, after passing through

the objective, would have beenemittedat &. The diffracted

rays, after passing through the objective, would have been

emitted at D. The emitting surface between B and D would

have been dark, as the result of the corresponding diffracted

rays interfering with one another. Thus, the points Band D

would have been utilizedas isolated points of emission. They

would have behaved as we have seen points in an aperture

uncovered by two widely separated slots behave. The result-

.ing picture would have differed from that desired as Photo. 2,

or 3, or 4, differs from Photo. 1. Then Photo's 2, 3 and 4 are

a pictorial warning for a second time, now a warning against the

use of oblique wlumination tn ordinary work as a means of

increasing or of attempting to exhaust the resolving power of the

microscope. At the same time tt becomes evident that every sub-

stage should be provided with a means by which its condenser may

be acccurately centered, and that every student using the macro-

scope should be familiar with a method of centering his sub-stage

condenser. These general rules should be accompanied by another:

the sub-stage condeuser| should be as well made as the best objec-

tive, and should be used with an ever present appreciation of its

power to improve or injure the picture of microscopic vision.

It is theoretically barely possible by means of homogene-

ous immersion and the use of violet light to about double

the resolving power of an objective, as compared with another

of the same focus used dry with white light illumination.

* Ibid.

t Powell and Lealand ‘‘apochromatic”’ and ‘‘achromatic’’ sub-stage condensers are

types of high quality. This cannot be said of the Abbe sub-stage condensers so commonly

used in laboratory work. Consult the Dallinger-Carpenter edition of THE Microscopr AnD

ITs REVELATIONS, from page 248 to page 263.

392 A. CLIFFORD MERCER:

So, while BD in Fig. 2 indicates nearly the greatest aperture

[nearly 180° in air, or nearly 1.00 N. A., or nearly an effect-

ive diameter of a quarter of an inch in a }-inch objective]

obtainable in a dry objective, A & in the same diagram indi-

cates the greatest possible aperture theoretically obtainable

with ordinary objectives by the use of homogeneous immer-

sion and shorter wave lengths. With the use of extremely

oblique light we have found that resolving power in a given

objective is about double what it is with principal axis illumi-

nation. Thus, with oblique light the aperture A & should

theoretically resolve points or lines about a quarter ofa white

wave length apart, or about 190,000 points or lines to the

inch. The extreme limit of resolving power shown in the

Abbe numerical aperture table is 193,037 lines to the inch.

[In this paragraph the circular aperture is supposed to be

the equivalent in resolving power of a corresponding rec-

tangular aperture. |

Practically, under the conditions suitable for best micro-,

scopic vision |p. 371], the theoretical limit of resolving power

foundin the Abbe numerical aperture table cannot be realized.

The extreme theoretical limit of the tableis that which would

be ‘‘about on the point of” realization with a rectangular

aperture and with the use of extremely oblique illumination

and violet light. But in practice we use a circular aperture

and—under the conditions suitable for best microscopic vision

—principal axis illumination. Moreover, Mr. Nelson* finds

that objectives transmit violet light only feebly. He also

finds that while the use of blue light increases the resolving

power of narrow aperture objectives it gives no better results

as to resolution than the use of white light in the case of a

wide aperture objective. For these reasons, any example of

actual resolution noted in the first column of the Abbe numeri-

cal aperture table is much less than the corresponding theo-

retical resolution found in another column of the table.

1.00 N. A. is the equivalent in resolving power of an

aperture of 180° in air. Therefore, in harmony with our

* Journal of the Royal Microscopical Society, 1893, p. 15.

THE PRESIDENT’S ADDRESS. 393

study of a rectangular aperture of 180° in air, from page

388 to page 391, 1.00 N. A. should with principal axis

illumination resolve points or lines one wave length apart.

In harmony with our study of the same aperture with the

same illumination, at page 340, points or lines half a wave

length apart should ‘‘be about on the point of resolution”

by 1.00 N. A. Then, in harmony with both these results,

our theoretical limit of resolving power for 1.00 N. A. in the

case of a rectangular aperture should be the resolution of

points or lines less than one wave length apart and more

than halfa wave length apart, ora number of lines to the inch

between 46,666 and 93,333, a wave length of white light

measuring qg$55 inch. The exact number of lines an observer

may see through an objective of 1.00 N. A. isuncertain. Vary-

ing keenness of vision is a factorinthe uncertainty. Another

factor in the uncertainty is the varying distinctness of the

image of each of the points or lines subject to resolution, due

to peculiarities* in the correction of the aberrations of the

objective or to the use of monochromatic light for illumina-

tion.

The results actually obtained by Mr. Nelson place the

limit of resolution for 1.00 N. A. with white light and principal

axis illumination at about 70,000 lines to the inch. This

result was obtained with a three-fourths cone of light between

the object and the objective and with a circular aperture. It

is interesting to note that 70,000 is three-fourths of 93,333

or that 70,000 stands just half way between 46,666 and

93,333. We may say that in practice 1.00 N. A. resolves

points or lines a wave length and a half apart. By

referring to Fig. 10 we see also that it may be said that a

circular aperture should thoroughly resolve, in ordinary cor-

rect use of the microscope, the details of an object which

would ‘‘be about on the point of resolution” by a square

aperture having a diagonal equal to the diameter of the given

circular aperture ; for the diameter of the circle A BC Disa

little less than the diagonal of the square bounded above by

* Ibid, p. 10.

394 A: CLIFFORD MERCER:

uv, below by wx, on the left by slot g and on the right by

slot 5, the breadth of the square being equal to three-fourths

of the diameter of the given aperture. If the limit of actual

resolution be about 70,000 lines to the inch for 1.00 N. A.,

the limit. for 1.40 N. A., nearly the highest numerical

aperture in common use, is about 98,000 points or lines to

the inch.

The more important results of our experimental study

of aperture may now be summarized. It appears that

diffracted rays leaving an object may be considered in the

same category with other rays changed in direction by an

object and that the diffraction phenomena seen in a projected

image are essentially the effect of changes in light above the

objective due to a function of aperture, and not to changes

below the objective due to diffraction of light in the plane of

the object. It also appears, however, that diffraction in the

plane of the object does, under some circumstances, furnish

light to certain parts of an aperture from which primary rays

are absent and thus enables aperture to more fully determine

the character of the projected image—resulting in a more

nearly truthful image or, on the other hand, in false appear-

ances: this is the gist of the Abbe phenomena of micro-

scopic vision. But it appears, too, that such phenomena are

not peculiar to microscopic vision, notwithstanding Prof.

Abbe’s claim to the contrary. Moreover, with any positive

lens similar and more brilliant results may be got by utilizing

corresponding isolated pencils of primary rays instead of

isolated pencils of diffracted rays. Still more trustworthy

results may be got by using continuous apertures three-

fourths [in diameter] full of primary rays instead of the

isolated pencils of primary rays.

An advantage peculiar to using narrow cone illumination,

the only illumination admissible in the Abbe theory with

its indispensable ‘‘spectra,” with an objective of wide

aperture has received particular attention in this paper

[for the first time, so far as the writer knows]. It has been

shown that a circular aperture diaphragmed down to be

THE PRESIDENT’S ADDRESS. 395

approximately the equivalent of a narrow rectangular aperture

and filled with primary rays gives the acme of trustworthy

resolving power possible in the corresponding diameter of

the objective. But resolving power is reduced in all other

diameters. Images projected by rays passing through such

an aperture would be distorted essentially as the images of

the dots a and @ in Fig. 3 are shown to be at a’ and 6’, or at

a’ and 6’’’. It has been shown that by means of narrow

cone illumination and an objective having a wide and

uncovered aperture it is possible under suitable conditions to

get approximately the acme of resolving power simultaneously

in each of several diameters as a result of our so-called

‘«selective power,” the above distortion being incidentally

eliminated. Thus a circular aperture ts approximately

squared or made rectangular as to resolving power tn several

of tts diameters stmultaneously. This approximate equiva-

lent of ‘‘squaring the circle”

advantage referred to as being peculiar to narrow cone

illumination with an objective of wide aperture.

Finally, special attention is called to the fact that the

Abbe theory deals with complex objects; for only such

objects are subject to resolution. Single particles and

as to resolving power is the

uniform areas are outside its domain. These latter, however,

are microscopic objects; and all objects are essentially

different shaped aggregations of points. The visibility of an

isolated point-like particle resembles the visibility of a star.

No matter what the distance of the star, it may be seen if it

has sufficient intensity. Ina similar way, an isolated point-

like particle—no matter what its minuteness—may be seen

if it present sufficient contrast with the surrounding micro-

scopic field. The size of the disc image in either case is no

less than a limit determined finally by aperture. That limit

in size, varying inversely with aperture, determines the limit

of resolving power. This is the gist of the theory of micro-

scopic vision which ‘harmonizes with our experimental study

of aperture. .

It has seemed to the writer that an attempt to explain the

396 THE PRESIDENT’S ADDRESS.

projection of an image of a complex microscopic object while

ignoring the projection of the images of the points of which

all objects may be considered aggregations resembles an

attempt to explain, for example, the. functions of a com-

plex organism while ignoring the functions of its cells. An

opposite course is more natural. In harmony with this more

natural course the writer has attempted to present to those

who may be interested an experimental study of aperture as

a factor in microscopic vision.

REPRODUCTIONS OF PHOTOMICROGRAPHS

PHOTO'S 1 TO 8 -

PHOTO'S 9 TO 18 - REPRODUCTIONS OF PHOTOMICROGRAPHS

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Recrology.

JAMES E REEVES, M.Dr ae. - janilary, 4, 1895.

SYEVANUS A] EEEIS MDs... March 24, 1806;

GUSTAVE GUTTENBERG, Pu.D.,. . June 29, 1896.

IECOUJUS) MEANS tr Wists (Cre oe Ro Ale oe! August 7, 1896.

JAMES EDMUND: REEVES, M. D.

Died at Chattanooga, Tenn., January 4, 1895, in his 67th year.

Dr. Reeves had been ill for a relatively short time

with some obscure affection of the liver. He was born in

Annisville, Va., and after an apprenticeship in the office of

his preceptors, began at the age of twenty-one the prac-

feerai medicine-in Sutton, W. Va. “A year later he took a

course of lectures at Hampden Sydney Medical College, of

Richmond. Nearly ten years later he took a second course

of lectures in the Medical Department of the University of

Pennsylvania.

While a resident of Wheeling, W. Va., he agitated the

subject of municipal hygiene and secured the passage of an

ordinance establishing a city health department. In 1869,

he was elected city health officer and county physician, and

continued in office for four years. Subsequently he served as

a member of the city council for four years. He was the

author of a law creating the State Board of Health of West

Virginia, of which he was a member, and for five years the

secretary. For about the last six years he lived at Chatta-

nooga.

398 THE AMERICAN MICROSCOPICAL SOCIETY.

Dr. Reeves was one of the founders of the American Pub-

lic Health Association, and its. president in 1885. In 1867,

he issued a call for the organisation of the State Medical

Society of West Virginia, whose first secretary he was, and

in 1881 its president. He was a member of the Executive

Committee for West Virginia of the International Medical

Congress, held at Philadelphia, in 1876. In 1882, he was

elected a member of the Judicial Council, and in 1895, a

trustee of the American Medical Association and a member

of the Association of American Physicians. He was one of

the vice-presidents of the section of Public and International

Hygiene of the International Medical Congress, held at Wash-

ington in 1887; vice-president of the American Microscopi-

cal Society in 1886 ; a member of the Advisory Council of

the Pan-American Medical Congress, held at Washington in

1893. He was employed by the State Board of Health of

Tennessee to make sanitary inspections of the State’s

defences against yellow fever during the Jacksonville epi-

demic of 1888.

In addition to numerous journal articles, Dr. Reeves was

the author of A Practical Treatise on Enteric Fever, and A

Manual of Medical Microscopy for Students, Physicians and

Surgeons. W.EL.S:

PROFESSOR: GUSTAVE GUTTENBERE:

Born May 10, 1843, died June 29, 1896.

By MAGNUS PFLAUM.

Science requires three classes of labor; there must be

gathering by investigators, arranging and understanding by

philosophers and spreading by teachers; and it would be

difficult to determine which of the three achieves the greatest

good for human progress and civilisation. Professor Gutten-

berg belonged to the last class, and by nature and training

he was unusually well-fitted for his duties.

PROFESSOR GUSTAVE GUTTENBERG.

Braedon RE\

NECROLOGY. 399

From what is known of his early life, it is not certain that

he intended to become ateacher. After finishing his educa-

tion at Vienna, Austria, with a degree of Ph. D., he became

the art correspondent at Paris and London of a Vienna news-

paper. He came to this country and spent almost five years

traveling in the pursuit of his favorite study, mineralogy, and

gathering specimens zz /oco. After two years of journalism

at Wheeling, W. Va., he became a teacher of languages and

science, in 1879, at Erie, Pa., and in 1889 entered upon his

useful career as teacher of biology at the Pittsburg Central

High School, since which time scientific studies received his

sole attention. His success in teaching science was as

remakable as hiserudition. He had the true teacher’s quality

of imparting and arousing enthusiasm in his pupils, and

by consummate patience, tact and judgment could smooth

the roughest road and make the study of nature a pleasant

task. Asa result he was adored by those he instructed.

He had a kind and generous heart and was unselfish and

self-sacrificing. Although one of the busiest of men, an

appeal to him for aid in any scientific work, as an opinion,

advice, assistance to an individual, or a paper, a lecture, or

any service fora society, received the kindliest response. This

promise was sacred and its performance was of a thorough-

ness as delightful as it was instructive to the recipients of his

favors.

He was a voracious student and what he learned he remem-

bered, and there was no limit to his studies excepting time

and his physicalendurance. Those who enjoyed his acquaint-

ance were amazed and surprised at the scope and accuracy of

his almost encyclopedic information, and had continual evi-

dence of his singular love of knowledge and his familiarity

with the whole range of natural science.

With a devotion to study and the most conscientious per-

formance of duties he combined a purity of soul and nobility

of character as befitted a student of nature. He was one of

the High-Priests. And withal he was as gentle and modest

as a maiden and cared least for public praise or approbation.

400 THE AMERICAN MICROSCOPICAL SOCIETY.

He lived a life of duty nobly performed. His last work

was the installation and opening of the museum of the Carne-

gie Library for the inauguration of the building, November 5,

1895. Although the means and the time given him were wholly

inadequate, he fully and creditably succeeded. But the wear

and tear told heavily upon his already weakened constitution.

Before the final completion of the work his health gave away,

and he died the following June.

His time did not permit him to render much service to this

society. He attended but one, the Washington meeting.

Had his life been spared he would have given more time to

microscopy. Being connected with the museum as one of

the trustees, and the president of the Iron City Microscopical

Society, which meets in the museum lecture-rooms, he had

planned a school of microscopy free to the public. Populari-

sation of science was his constant aim, and his early death

proved a public loss.

In him passed away one of the unknown great men.

CONSTITUTION.

ADOPTED AT ROCHESTER, N. Y., 1892.

ARTICLE. |

This Association shall be called the AMERICAN MICRO-

SCOPICAL SOCIETY. Its object shall be the encouragement

of microscopical research.

ARTICLE se

Any person interested in microscopical science may

become a member of this Society upon written application

and recommendation by two members and election by the

Executive Committee. Honorary members may also be

elected by the Society on nomination by the Executive

Committee.

ARTICLE III.

The officers of this Society shall consist of a President and

two Vice-Presidents, who shall hold their office for one year,

and shall be ineligible for re-election for two years after the

expiration of their terms of office, together with a Secretary

and Treasurer, who shall be elected for three years and be

eligible for re-election.

ARTICEE, LV:

The duties of the officers shall be the same as are usual in

similar organisations ; in addition to which it shall be the

duty of the President to deliver an address during the meet-

ing at which he presides ; of the Treasurer to act as custo-

402 THE AMERICAN MICROSCOPICAL SOCIETY.

dian of the property of the Society, and of the Secretary to

edit and publish the Proceedings of the Society.

ARTIGER? V;

There shall be an Executive Committee, consisting of the

officers of the Society, three members elected by the Society,

and the past Presidents of the Society and of the American

Society of Microscopists.

ARTICLE, Val.

It shall be the duty of the Executive Committee to fix the

time and place of meeting and manage the general affairs of

the Society.

ARTICEE VIL.

The initiation fee shall be $3.00, and the dues shall be

$2.00 annually, payable in advance.

ARTICLE VIII.

The election of officers shall be by ballot.

ARTICLE IX.

Amendments to the Constitution may be made by a two-

thirds vote of all members present at any annual meeting,

after having been proposed at the preceding annual meeting.

BY-LAWS.

Ife

The Executive Committee shall, before the close of the

annual meeting for which they are elected, examine the

papers presented and decide upon their publication or other-

wise disposal of them.

CONSTITUTION AND BY-LAWS. 403

All papers accepted for publication must be completed by

the authors and placed in the hands of the Secretary by

October Ist succeeding the meeting.

The Secretary shall edit and publish the papers accepted,

with the necessary illustrations.

III.

The number of copies of Proceedings of any meeting shall

be decided at that meeting.

PNG

No applicant shall be considered a member until he has

paid his dues. Any member failing to pay his dues for two

consecutive years, and after two written notifications from

the Treasurer, shall be dropped from the roll, with the privi-

lege of re-instatement at any time on payment of all arrears.

The Proceedings shall not be sent to any member whose dues

are unpaid.

The election of officers shall be held on the morning of

the last day of the annual meeting. Their term of office shall

commence at the close of the meeting at which they are

elected, and shall continue until their successors are elected

and qualified.

Candidates for office shall be nominated by a committee

of five members of the Society. This committee shall be

elected by a plurality vote, by ballot, after free nomination,

on the second day of the annual meeting.

404 THE AMERICAN MICROSCOPICAL SOCIETY.

VII.

All motions or resolutions relating to the business of the

Society shall be referred for consideration to the Executive

Committee before discussion and final action by the Society.

VIII.

Members of the Society shall have the privilege of enroll-

ing members of their families (except men over twenty-one

years of age) for any meeting on payment of one-half the

annual subscription ($1.00).

Approved by the Society, August 11, 1892.

LIST OF MEMBERS.

The figures denote the year of the member's election, except 78, which marks an original

member. The TRANSACTIONS are not sent to members in arrears, and two years’ arrearage

forfeits membership. (See Article VII. of the Constitution.)

Members Elected at Pittsburg, Pa., 1896.

For addresses see regular list.

ANGLE, Epwarp J., B. S. HEALD, GEorGE Henry, M. D.

BarRKER, ALBERT S. HorrMan, Jos. H, M.D.

BARTLETT, CHARLES JOSEPH, M. D. KELLOGG, CLiFForpD Wa tcortT, M.D.

BEAL, Prof. JAs. HARTLEY LEIpPE, J. HARRY

Bopine, Prof. DoNALDSON Lotrurop, Eart P., M. D.

Boycg, JoHun W, M.D. MarSHALL, CoLiins, M. D.

Bray, THomas J. Matson, EuGEnE G., M. D.

BREDIN, GEo. S. MeEapDER, LEE Douctas, M. D.

BurneEr, NATHAN L. Morck, AUGUST

CARPENTER, THos. B., M. D. OLSEN, ALFRED BERTHIER, M. D.

CLarK, GayLorp P., M. D. Rice, FRaNcIsS SCOTT

CLaRK, GEORGE Epw., M. D. SAMPSON, ALLEN W., M. D.

CunninGHAM, M. C. ScHMITZ, HENRY

Dean, N. B. H., M. D. SCHWERDTFEGER, Louis CHARLES, Eso.

DEFENDORF, ALLEN Ross, M. D. SmItTH, CHauncEy P., M. D.

DIEHL, ALFRED C., M. D. STEWART, ALONzO, M. D.

Dorr, L. Brapiey, A.B, M.D. STOCKWELL, RopneEy R.

Dort, Miss ELIZABETH STONEY, ROBERT J., JR.

Evans, Cuas. H., M D. TuHoma, FRIDOLIN, M. D.

Ferris, Prof. Harry B. Tuomas, Miss Mary E, Ph. B.

FLEMING, Miss Mary A. THORNBURY, FRANK J., M. D.

GaTES, ELMER TIMMINS, GEORGE

GREEN, Miss IsaBELLA M., M.S. TWINING, FREDERICK E

Hays, Jos. A.

ABERDEEN, RoBERT, M.D., F.R.M S., 82, Aye ety Lacusew New Ne

Acker, Geo. N., M.D., '9I, . . . 913 Sixteenth St, N. W., Washington, D. C.

AINSTIES GHARELESPNE, (92, 5 5 cies co ~~ wets . . . Rochester, Minn.

ALLEGER, WALTER W., M.D.,’94, - - . 906S.St., N W.. Washington, D. C.

ANGLE, Epwarp: JB. S.790, > - <..04 s = =). 1400:OSE, Lincoln, Neb.

406 THE AMERICAN MICROSCOPICAL SOCIETY.

ARWOGD 2B 95°79). 3 +e ee «+ =» «>» 261 W. 34th) St. Newavonk

Atrwoop, H. F, F. R. M. an 128, s bhe & lee Ss) wa sos, RROGRESLeGIEN ERE

Avrers, Morcan W., M.D. '87; 2. => - =. .1- Upper’ Mont iGlaireNege

BaLL, MIcHAEL VALENTINE, '93,. - . - . 1132 Spruce St., Philadelphia, Pa.

BarkER, ALBERT S., ‘97, . .. .. - 24th and Locust Sts., Philadelphia, Pa.

BARNSFATHER, JAMES, M. D., ’ol,

Cor. Fairfield Ave. and Walnut St., Dayton, Ky.

Barr, Prof. CHas E.;’90,. -..-.. . . . - Albion College, Albion, Mich:

BARTLETT, CHARLES JOSEPH, M. D.,’96,... . .- . . . New Haven, Conn.

Bassett, Cuas. H., '82,. . BS Ne Ne TN Ma ape et LO) Bedford St., Boston, Mass.

BAUSCH, EDWARD, 79) = - + © » y -X7ON: ob PauliSt Rochester sa inme

BAUSCH GRO OOsneic) et ane el ies chee . . 20 Arcade St., Rochester, N. Y.

Bauscu, Henry, '86,.. . wo AG Rey Btn . . Rochester, N. Y.

BauscH; WIiLIAM, 188; 2.503. .0'o mS ws tee Ge Se ee EROGHEStO TING

BEAL, Prof. JaMES HarRTLEY, '96,....- ... > oe wOClo pO bias

BEE, CLARK, SOs, 92) saat ic Tee oeSt 7 Braaita New York City.

BENNETis LUENR Yo Cag OBieg te steam © ouleel a. ax W. 42d St., New York City.

BIGHT Owe te gilsmO2 colo sma tai paieraam tte woh ae e% : Portlal Conn.

Biscogz, Prof. THomas D.,’9I,.. . . . . . 404 Front St., Marietta, Ohio.

Bierce, A. M., M. D., ’81, . . State Hospital for Epileptics, Galiopolis, Ohio-

Bovine se rots DONALDSON). 905.0) ee) eels . Crawfordsville, Ind.

BootH, AUGUSTINE Rug, M. D., 87, .. . . . 520 Market St., Shreveport, La.

Boot, Mary A., F. R. M.S., ’82, . . . . . 32 Byers St., Springfield, Mass.

Boyce, James C., Esg, '86,. . ..- . . . Carnegie Building, Pittsburg, Pa

Boyce, Joun W., M. D.,96, . - - . ~~ . 23 Mawhinney St., Pittsburg, Pa.

Bover, C. Si, -AssM:; '92,. ...-. « «0's . 3223 Clifford'St.,; Philadelpheaygea-

Bray, Tuos. J, 96, iis we sls 6 .) 315 Park Aves) Warren @bios

IBREDINAIGE OSs OOM a cubital yeckey 6c feces, cena “(ot A OUiGityeetes

Bromiry, Rosprr innis; M.D: '93,.00-. . = <«). 6. 2). 1.) ee SOOEAREIGale

DROW ae. MEGS IES) 4 CM so see Molo ofp ch oe a © « AngelicayyNn oe

Brown, N. Howranp, 'ol,. . -..-.- -.- = 33S- Toth St., Philadelphia, Pa-

Brown, Rosert, ’85, . . ... . + + Observatory Place, New Haven, Conn.

IS RUNDAG re reAG ble slvr) a OA eee Ure 1153 Gates Ave., Brooklyn, N. Y.

Butt, James Epaar, Esg., ’92,. . - - - 253 Broadway, New York City, N. Y.

BuLt, James, '88, . Shim Sie . . . Hanging Rock, Ohio.

Burner, NaTtuHan L., M. D., eae. TS ey: _ 368 emit Ave , Columbus, O.

BURRICE, lee |e exnen = ai R MS 85) yoo : . . Champaign, IIl.

BURT, Exot. EpwARD Am Ohne 4 8 E Middlebury College, Middlebury, Vt.

Busco. FREDERICK CarRL, 95, - . + + + - 179 Richmond Ave., Buffalo, N. Y.

Busu, Bertua E, M.D.,’95,. : . . . . - 808 Morse Ave, Rogers Park, Ill.

Butto.ipa, Harry T.,C. E., 80, -.. .- =. - - « 13 City Hall, Buttalo, Ney.

CamMPBELL; D. PM. Di, '88, 6: 2... .... . = -Green Springs aie

CARPENTER, Aides Be M. 1D) 196 Cd qa Jersey St., Buffalo, N. Y.

CARTER, JOHNIE. 150) eel ee ee ity et Germantown, Philadelphia, Pa.

THE AMERICAN MICROSCOPICAL SOCIETY.

Cassatt, M., M. D., ’86, .

CHEESEMAN, E.L,’84, .

CHESTER, ALBERT H ,A. M.,

Crapp, Gro. H., ’86,

CLarK, GAYLORD P., M. D; 6h

CxLarkK, GEORGE Epw., M.D., ’96, .

CLaYPOLE, AGNES M., 94,

one

CLAYPOLE, EDITH a Phe Bi Mis: 93:

B Se. F. GoS., ‘36;

CLAYPOLE, EpwarpD W..,

Coss, Cuas. N., A. M., '86, .

ConsER, Harry NEWTON, ’95, .-

Coon, H. C:;, A.M, M. ae 1OZs =

Coorg, A. F.; M. D., ’86,

Coucnu, Francis G., '86,. . ;

Cox GHASy Ee RoM: Ss, 85: 4

Craic, THOMAS, '93, - ;

CRANDALL, Ranpb Percy, M. D., ’g1,

CuNnNINGHAM, M. C., 96.

CURTISPICESTER MD) 5, 7Q; -. + ve,

DanieEts, C.M.,M. D.,

Davis, W. Z., '86, .

Dean, N.B.H, M.D., '96,

DErcKk, IymMan L., M.D.;,'90; =.

DEFENDORF, ALLEN Ross, M. D., ’96,

{seh c

DIRE VATERED) G. Me). .°90,... or. «

Dorr, L. Brapvey, A. B., M. D., '96, .

Dorr, S. Hopart, Ph. G., '95,.

Dort, Miss ELIzaBETH, ‘96,

DousLepay, Henry H, Esg., '90 .

DrEscHER, W. E., 787, .

DunuaMm, E. K, M.D, ’92,.

407

- 313 Elm St., Cincinnati, Ohio.

Knowlesville, N. Y.

hier Callaxe® New Brunswick, N. J.

. 116 Water St., Pittsburg, rs

aD Syracuse, N.

Paiencatetes Onondaga Co., N. =

. Akron, Ohio.

wcllestey allege Wellesley, Mass.

2 . Akron, Ohio.

. 26N. Pine St., Albany, N. Y.

Lock Box 657,, Sunbury, Pa.

. Alfred University, Alfred, N. Y.

. 114 Sycamore St., Oil City, Pa

. 846 Broadway, New York City.

. Grand Central Depot, New York City.

CraiG, CHARLES FrANcIs, M.D., '94, .

- 301 Main St., Danbury, Conn.

244 Greenpoint Ave., Brooklyn, N. Y.

. Navy Pay Office, San Francisco, Cal.

- Board of Health, Pittsburg, Pa.

. 35 University Place, Chicago, IIl.

Buffalo, N.Y.

. Marion, Ohio.

: i veung St., Brighton, Ont.

. Salamanca, N. Y.

. Worcester, Mass.

aoe idee . Buffalo, N. Y.

. 300 Jefferson St. Buffalo, N. Y.

. 887 Prospect Ave., Buffalo, N. Y.

. 608 Fillmore Ave., Buffalo, N. Y.

. 715 H St., N. W., Washington, D. C.

. Box 1033, Rochester, N. Y.

- 315 Jersey St,

Bellevue ‘Boswital Med. College, New York City.

Eastman, Lewis M.,M.D, F.R.M S., 82, 772 W. Lexington St., Baltimore, Md.

EIGENMANN, Prof.C. H., ’95,

ELuiottT, Prof ArTHUR H, ’9gI,

ELSNER, JOHN, M.D, ’83, -

EWE. AS i (SO: :

ENTRIKIN, F. W , M.D, ’87,

Evans, Cuas. H., M. D., ’96, .

. University of Indiana, Bloomington, Ind.

. 2Ist St. and Avenue A, New York City.

P. O. Box 454, Denver, Col.

. 16 Pearl St, Council Bluffs, Iowa.

. Over 520 S. Main St, Findlay, Ohio.

. Canton, Ohio.

EwELt, MarsHALt D., LL. D., M. D., z. R. M. S- 8s,

Bere, Anorry,-M. DSi, > (2. foe

Bere Grook:. MD. Ee. ReM-S., 78, -

FELLows, Cuas.S,F. R.M.S.,’83,

13 and 614 Ashland Block, Chicago, Ill.

. 520 Main St., Columbus, Ohio.

72 Niagara St, Buffalo, N. Y.

D. 23 Produce Exchange, New York City.

408 THE AMERICAN

Ferris, Prof Harry B , ’96, .

Fietp, A. G., M. D., ’82,

FIeLp, Miss Eva H., '94, . aa

Fisu, Prof. Prerre A., D. Sc., 90, .

FISHER, Max, ’93,.. - :

FLEMING, Miss Mary A., ae

Fiint, JAMES M., M. D., ’9gI,

Fox, Oscar C., ’92, 3

Forp; Prof. D: R:, D. Ds am

FosTER, AGNES Wikcuow: ‘Oe o 6

BRANCIS, MARK: M.D» DiVe Me, +87, =

FRENCH, GaLz, M.D., '86,..

FRENCH, S. H., M. D., '82, .

MICROSCOPICAL SOCIETY.

. Yale University, New Haven, Conn.

. Summit Place, Des Moines, Iowa.

5 Des Moines, Iowa.

Cornell University, Ithaca, N. Y.

. Zeiss Optical Works, Jena, Germany.

13 W. Chippewa St., Buffalo, N. Y.

. I117 Vermont Ave., Washington, D.C.

ix . Washington, D.C.

Renate College, Elmira, N. Y

ras Brewster, Mass.

= Galles Station, Brazos Co, Tex.

. 5219 Center Ave., Pittsburg, Pa.

. 40 Church St., Amsterdam, N. Y.

Futter, Cuas. G., M.D., F. R. M.S.,’81, 38 Central Music Hall, Chicago, Ill.

GAERTNER, FRED., M. D., ’87, . .

GAGE, Prof. Simon H. B. S., ’82,

GaGE, Mrs. SuSANNA S. PHELPS, '87,

GaTEs, ELMER, '96, . J *

GILBERT, JOHN L., M. D., ’94, .

GLEAsON, S. O., M. D., ’8o,

GoeETz, Rev. GEORGE, '9QI, .

GREEN, Miss ISABELLA M., M.

GREGORY, JAMES C., M. D., 93,

GRIFFITH, BENJ. W., '92, . -

GRIFFITH, J. D., M. D., ’87,

Saigon

- 3519 Penn Ave, Pittsburg, Pa.

. Cornell University, Ithaca, N. Y.

Tthacay Neve

ee . Chevy Chase, Md.

917 Kanes Ave., Topeka, Kansas.

., Elminay Neaye

ORogbestes Beaver Co., Pa.

. 213 N. Union St., Akron, Ohio.

. Nyack-on-Hudson, N. Y.

. . 1241 W. State St., Los Angeles, Cal.

Rialto Building, cor. Ninth and Grand, Kansas City, Mo.

HAAG. DE vie Ds Re

Hanaman, C. E., F. R. M.

Hanks, HEnry G., '86, .

HARDING, LAWRENCE A., B. Sc.,

HATFIELD, JOHN B., '82, .

EVAYS; POS. A. 5:96). : :

HEALD, GEORGE Hee M. D. "96, .

Hk&INEMAN, H. Newron, M. D., ’gI,

Hit, HERBERT M., Ph. D., ’87, .

Hoenny, A. J., '87, .

HorrMan, Jos. H., M. D., 96,

Hovsrook, M. L., M. D., ’82, ..

M. S.,

S., '79,

HOLMES 9.15.00 e D1 Si sod:

Hopkins, GRANT S., D.Sc., '99, -

Hoskins, Wo., '79, . Vp Ute witkes its

Howarp, Curtis C., M. D., '83, .

HowE, Lucien, M. D., F.R. M. S.,

Hupser, Rev. E. D., ‘$2,

Huser, G. Cart, M. D., F. R. M. S., 90,

ene Wrouteomeey Ship

Ph, D290).

. 1121 Washington St., Toledo, O.

: Box 527, Lroy, Na

San Francisco., Cal.

16 Seventh St., St. Paul, Minn.

. 189 Arsenal Ave., Indianapolis, Ind.

. 147 S. Eighteenth St., Pittsburg, Pa.

F Speus . Battle Creek, Mich.

es W. Fifty-sixth St., New York.

ae . 24 High St., Buffalo, N. Y.

. 3631.N. Grand Ave., St. Louis, Mo.

III Steuben St., Pittsburg, Pa.

. 46 E. Twenty-first St., New York.

. Grand Rapids, Mich.

. Ithaca, N.Y.

Si Ss. Clark St., Chicago, Ill.

staring Medical College, Galen O.

2793 -

. 87 W. Huron St., Buffalo, N. Y.

1300 E. Fayette St., Baltimore, Md.

. 24 E. Ann St., Ann Arbor, Mich.

THE AMERICAN MICROSCOPICAL SOCIETY. 409

ECUMPLIREY; Oss Hohe Dios items yous. 227, WV EaehthuSt.,, ries ba.

Hunt, JosepH H.,M.D., ’94,. . . . . . 1085 Bedford Ave., Brooklyn, N. Y.

EVAR a 7/55)- ee nae OSL burling iaanes New slvochelles Nave

Jackson, CuEvALigr, Q, M. D.,’87,.... . . . 63 Sixth Ave., Pittsburg, Pa.

JAMEs, BusHrRop W., M. D.,’94,

N. E. cor. Green and Eighteenth Sts., Philadelphia, Pa.

JAMES RANG. . eh. DS VS D820) 2.) OFS locust st, St. Louis, Mo-

jfamES; GEO. W 92, .. P ySOr le) LOO Wake St., Chicago, 111,

JOHNSON, ee Sh MSDS, 83, Ee ae oe 2521 Prairie Ave., Chicago, III.

Jounson, HL. E., M.D.,’91,.. .. . . 1400 L) St. N. W.. Washington, DiC.

KeELiicoTr, D.S., Ph D.,F.R.M.S,’79,. State University, Columbus, O.

KEEEOGG; J- b.. M.D, 78; -~ = Battle’Greek, Mich?

KELLOGG, CLIFFORD eon M. D.. 96, a 4 Dwight St., New Haven, Conn.

KENNEDY, THOMAS, ’90,.. . BOS eey Bebe New Brighton, Pa

KENNEY, HERBERT EASTMAN, ’'QI,.-...... . . .eittleton IN) He

ERR, PAB RAMs SUCKER mR. jiO5 nemie sens. 8 3) tes "1368 Main St., Buffalo, N. Y.

IINGSBURY,) DENJAMIN: Ee eA pe MES O45... « = . «2 os 4» Lthacay Nave

IMRKPAERTGad apy (O35 ye aete cheese ek i ce . . . Springfield, O.

LESQUNDS Wifi 18 IW ee DR oye s85 eaoiel ea chao, 5 280) Wabash Ave., Chicago, Ill.

Nome Nae eeu eo) OL me iain 5 SPS hounth: Stapbeaston bar

KRAFT, WILLIAM, '95,... - ee 4k Wi 50th) St. New, ork:

Krauss, Wo. C., B.S., “M.D., F.R.M.S, ‘90,

371 Delaware Ave., Buffalo, N. Y.

PRONE RE We, (79) 52% ss Gienm ss 2-3 79 Court St. Port, Wayne, Ind:

Langs, J. Mervin, M.D., '9!1,... - . . 906 GSt. N. W., Washington, D. C.

LANDSBERG, A,’79,....-....- . . - 145 Woodward Ave., Detroit, Mich.

Lascuk, ALFRED, ’92,.-..... - - . - Lake and Franklin Sts., Chicago, Ill.

LaTHAM Miss V. A., M.D., D. D.S., F.R.M.S , 88, 808 Morse Ave., Chicago, III.

IAWAON SEY DIVARD) ser OOs! ees a) 2) a. - - + 3 Linden Ave:; Troy, N7 Y-

LEBER, FREDERICK C., M.D.,’90,. . . . 550E. Jefferson St., Louisville, Ky.

EEEIPPE, | HIARRY, 90H. ke = > & = 336 Pine St, Philadelphia, Pa:

Lewis, Mrs. KaTHARINE B., ’89, . ‘‘Elmstone,’’ 656 Seventh St., Buffalo, N. Y.

EE WHS HAL RAUNV Es ROW seeita atl oleate Poteet Seite ot Ghee of Te Se) Dixon. Gs

Lewis, Wo. J., M. D., ’83,

812 Bennett Building, cor. Fulton and Nassau Sts., New York.

MAGEE ETO AW M., EYASCi'SO,l. 1 fe 5% «she s+ oe! Princeton, Nias

Linz, J. Epwarp, D.D.S.,F. R.M.S,’82, .. . 39 State St., Rochester, N. Y.

EOC KE MOHNG DD wOSsrercct ice sec) cee 6) i at . . . Box 129, Haverhill, N. H.

Wom yADOLPHA 92,5. 0% ele LO 38 Clinton Place, Rochester, N. Y.

WoMEnGARL EEE 7 Ot = on a LO No St. Paul St. Rochester Naw

Loms, Henry, ’84,: .- . - ss... - . 48 Clinton, Place: Rochester, N. Y.

Lorurop, Eart P., M. D., Bb 71. + » «|. 153) Delaware Ave:, Buffalo) N.Y.

EovEybtore2.G., Ol, 2s 2a sas « . . . 69 -E. 54th st. New Yorks City,

Lyon, Howarp N., M.D.,’84,... ... - . 39 Belleview Place, Chicago, IIl-

410

Manton, W P.,M.D., F.R.M.S,’85, ..

MarsHALt, Cottins, M. D., ’96,. ..

MarsHALL, WM., JR., '92,.

THE AMERICAN MICROSCOPICAL SOCIETY.

32 West Adams Ave., Detroit, Mich.

. 2507 Penn Ave., Washington, D. C.

. Coudersport, Pa.

MaTHER, EnocH, M.B,M D, D. D. S., Ph. D., D.C. L., Li. DEeass

Matson, EuGEeneE G., M. D., ’96, . .

MGCAETA “AUBERT Eb haiD sy SOnn. oe

McGreGor, JAMES H., ’95, -

McKay, JosEPH, ’84, . ,

McKim, Rev. HASLETT, '85, - -

MacKay, A. E., M. D., ’9I,

Meaper, LEE Douaras, M. D., ’96,

MELLor, Cuas C.,’85,

Mercirr, A., M.D.,’95, -

MERCER, A. Cummonn, Mie Ds EF R. M. ‘s,

MERCER, FREDERICK, W.,

Miter, Joun A., Ph. D, F.R.M.S., ’89,

Minor, Cuas. G, '86,

Mirtinc, E. KENNARD, '92, Sake

Moopy, Mrs. Mary B., M. D.,’83, .

Moopy, Rosert O., M. D., ’91,

Morck, AuGustT, '96,. . Sin

Moors, Prof. V. A., M. D.,’87, -

Nunn, Ricuarp J., M. D., '83,. . -

OERTEL, T. E, M. D., '92,

OHLER, W H..,’g!,

Oyeraety leo (Gy WIE ID) Ckon GS -

OxseN, ALFRED BerTHIER, M.D,

Paguin, Paut, M..D., ‘gI,- -

Park, Roswetit, A.M, M.D.,

PaTcHEN, York, M. D ,'84,

PaTRICcK, Frank, Ph. D., 'gl,

Prask, FrepD N., '87,.- -

PENNOCK, ED.,’79 .- suits

Perry, Stuart H., Esg.,’90, -

Priaum, Maaenus, EsgQ., '91,

Piatu, Otto E, M.D.,’91, .N.

PRENTICE, WM. J.,'87,-. -

Pyzpurn, GEorGE, M. D., '86,. .

EuGENE A., '86, .

Rau, é

, M. D.. tam:

REMINGTON, Jas P

WYiS IDEs Lee dees vl (Sy

Hope 5 oc

124 Hamilton Ave., Patterson, N. J.

. Board of Health, Pittsburg, Pa.

414 Monadnock St., Chicago, Ill.

. 249 W. 55th St.. New York.

ve 245 Eighth St, Dsoy,eNee

33 West Twentieth St., New York City.

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116 W. Seventh St., Cincinnati, Ohio.

.77 Fifth Ave., Pittsburg, Pa.

Zurich, Switzerland.

324 ae St.,

, 83,

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Niagara University, Buffalo, N. Y.

. 318 Highland Ave., Pittsburg, Pa.

326 N. Water St., Chicago, III.

Syracuse, N. Y.

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. Cornell University, Ithaca, N. Y.

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THE AMERICAN MICROSCOPICAL SOCIETY. Sania

REYBURN, Rosert, M.D.,’90,. ... . 2129 F. St., N. W., Washington, D.C.

REYNES, PLACIDE, ’87,...... . . . . 204 Baronne St., New Orleans, La.

RICH PERANGIS| SCOLT, JOO, een) wen t23) eonmore St elmira, Ne Yio-

TCH GEO. VW, 19002 = 2 ee oO srioh Sts Detrolty Mich:

Rossins, Henry A., M. D., ’ol, - . 1750 M. St., N. W., Washington, D. C.

ROGERS) Prof, Wm..A., A> M., Honk, B.R: M.S: 782, - . . Waterville, Me.

Row vey, Prof. WiLtLarp W., D. Sc., ’90, . . Cornell University, Ithaca, N. Y.

INWSMy CWO5 OAye Sone sie 2 6 6 5 0 a6 Oa IEE Os leob< Doe} IDlsnk ere, Corl,

SAMPSON ALLEN WM -D):5 196). tus leno oe ea benny Y anaNnve

DSCHAUREUBERGER, 2. J, ML D)., (OO) cron een 7283 gecund St., Hastings, Neb.

SCHRENK, HERMANN VON, '93,.. . . - Manual Training School, St. Louis, Mo

SCHMIPZ ITENRY, (90). 2 «ost noe . . 518 W. Chicago Ave., Chicago, Ili.

SCHWERDEFEGER, Louis CHARLEs, Esg., '96, .. . . . Lincoln, Logan Co.,, Ill.

SEAMAN, Wm. H, M.D., '86, . . 1424 Eleventh St., N. W.., Washington, D.C.

SECOR «ABN Aus) .O5:=) entiation etal iets S68 O16 9 bo = LMhiaA IS YE.

Srymoor, Prof. M. L., 85, Rooms 9 and Io, 323 N. Me. St., Los Angeles, Cal.

SHEARER, [7 1/05) 2-15) -") + => = + - 600) Adamsist., Bay City, Miche

SHERMAN I VALTER) Nef VU-00) 1100, sullen 28) ee MetrcedsCal:

Sriiensz | GHASmSsvO2en . Bul alin, eel, ea burs ... . «|. Hoboken; N- J.

SHURDEN 2 ler VED tok ee eet been cane ih jederen Ave., Detroit, Mich.

SIEMON, RUDOLPH, ‘QF, .. .. . . .'. 22 E. Jefferson St., Fort Wayne, Ind.

SLoan, Joun, M.D ,’80, . . . ..E. Sixth and Main Sts., New Albany, Ind.

SLOCUM AGHAG. Brewin. 1 Vile ID 7Oo) 6 al enneEe 2) 2) es Defiances Ohio:

SMI. CHAUNCEY b.,M- Ds," 196, 2 5 4. 489 Deeweee Ave , Buffalo, hs

SPENCER, HERBERT R.,’85,....... . . . 367 Seventh St., Buffalo,

STEDMAN, J. M., ’87, Bkoey rid aks aaa Pps . . Columbia, He

StEwART, ALONZO, M ID.."96,. 5 5 5 ; ie N. Twelfth St., Philadelphia, Pa.

STiLitson, J. O., A. M., M.D., 80, . . . 245 N. Penn St., Indianapolis, Ind.

STOCKWELL, Ropnery R., '96,. . .... . . . 553 Broadway, Alliance, Ohio.

Stronzy, Roperr J., Jr.,’96,........ . .P.O. Box 363, Pittsburg, Pa.

STOWELL, THomas B., A.M, Ph. D., '82, . . Potsdam, St. Lawrence Co., N. Y.

SUMMERS pe eLO tele E. p50, site) te Cage of Illinois, Champaign, III.

SYLVESTER, WILLIAM H., M.D.,’90,. . . . . 6 Clarendon St., Natick, Mass.

TayLor, Tuomas, M. D., '79, 238 Massachusetts Ave., N. W., Washington, D.C.

TERNAN, JAMES C., '93, . . Bausch & Lomb Optical Co , Rochester, N. Y.

ELH ONAC EEO RTDOLIN ele) 92 OO,n teem ais ee ee ees) es Uttalo. Naver

Tuomas, Miss Mary E., Ph. B,’96, .. . . . Meyersdale, Pa.

Tuomas, Prof. Mason B.,’90,. .. . wanes ealleze Crawfordsville, Ind.

THORNBURY, FRANK J., M. D.,’96. . ... . 405 Delaware Ave., Buffalo, N. Y.

Tirrany, Firaver B., M D.,’86,. . . . . 1235 Grand Ave., Kansas City. Mo.

sINiMINS GEORGE, .O0; qm oa as 6 6 wos ss 8 po 5 oF co SNAKES, INI, NA

MIEN GID Ven||s, VIR Dt 2OOh gs eats) cP rem si ve. eo 'p. O. Box 425, Pittsburg, Pa.

Abaya, \iifoulelee ts) (ae - . . . . 207 N. Second St, St. Louis, Mo:

TOLMAN, eee IL, a R. M. S., '83, - 923 Opera House Building, Chicago, Ill.

TURNER HENRY H.. IBA. eves «ee o) » = 45 Stoners. asochester, Naw

AZ THE AMERICAN MICROSCOPICAL SOCIETY.

TwINING, FREDERICK E.,’96,.. .

TWITCHELL, GEo. B., '86, . .

VANDERPOEL, FRANK, M. E., '87, .

VEEDER, ANDREW T., M. D., ’83,.

VEEDER, M.A., M. D., ’85,. .

Vorce, C. M., Esg., F. R. M.S., ’78,

VREDENBURGH, E. H., ’84,

WAGENHALS, Rev. SAMUEL, '82,. .

Wan; JoaneL., F:.R..M_S., +73;.-

Watns_Ley, W. H., F. R. M.S.,’'78,. .

Warp, Prof. HEnry B., A. M., Ph.D,

WEBER, Henry A., Ph. D., '86, .

WEIGHTMAN, Cuas. H., ’86,. .

WELCH, (GEO: ©) M. Dior. aa -

WENDE, ErRnEsT, M. D., '9g1,

WervuM, J. H., '93, .

. P. O. Box g90, Newark, Ohio.

. . . 556 Freeman Ave., Cincinnati, O.

191 Roseville Ave., Newark, N. J.

. Horne Office Building, Pittsburg, Pa.

. Lock Box 1108, Lyons, N. Y.

. . 5 Rouse Block, Cleveland, O.

. . 122 S. Fitzhugh St., Rochester, N. Y-

ema gek aayes Box 382, Fort Wayne, Ind-

. 338 Sixth Ave., New York City.

134 Wabash Ave., Chicago, Ill.

ion

University of Nebraska, Lincoln, Neb. '

. 1342 Forsyth Ave., Columbus, O.

. 5859 Michigan Ave., Chicago, IIl.

. Box 416, Fergus Falls, Minn.

471 Delaware Ave., Buffalo, N. Y.

. Toledo, O.

Weresn CHAsai,, Lic. Ds F. R. M. S., ae 6 Pierrepont St , Brooklyn, N. Y.

WESTOVER, H. W., M. D., 86, .

. 7th and Edmond SG. St. Joseph, Mo.

WHELPLEY, H. M., M:D., Ph. G., F.. RK. M.S, ‘90;

WHITE, JONATHAN, EsgQ., ’gI,

White, Moses C., M.D, '85,.

Wait ey, James D., M. D., '85,

Wiarp, Martin S., ’86,

WIEGAND, KaRL’ MaKay, Be S594)

WIEBERNGEO. DeMiD O35. a. is

WILLIcH, CHAS., JR., ’90, .

WILtson, Leonipas A., Esg., '85, .

Witson, Mrs. Mary R., M. D., ’’95,.. .

Woopwarp, ANTHONY, '85,

Woo.tmaNn, GEo. S.’'79,. .

Youne, Aucustus A., M. D., ’92, .

YznaGa, JosEM., Esg., '90,. ... .

ZENTMAYER, FRANK, 'OI, .

2342 Albion Place, St. Louis, Mo.

. 254 Main St., Brockton, Mass.

. Box 1674, New Haven, Conn.

abs, Gamabeowe a Mee . Petersburg, Ill.

. 21 Walnut St., New Britain, Conn.

. Ithaca, N. Y.

wee Gilpin St., Denver, Col.

. 696 President St., New York City.

. 112 Public Square, Cleveland, O.

: : . Lthaca, Ney.

; oe wW. 128th St., New York City.

116 Fulton St., New York City.

2 Newark, Wayne Co., N. Y.

. May Building, Washington, D. C.

209 S Eleventh St., Philadelphia, Pa.

THE AMERICAN MICROSCOPICAL SOCIETY. 413

HONORARY /IEFIBERS.

Eon VACORD) pelle Ea ME Oren. Veer. stn. so oo ear CAneinnatt, “O,

Crisp, FRANK, LL. B., B. A., F. R. M. S.,

5 Landsdowne Road, Nottingham Hill, London, England.

DALLINGER, Rev. W. H., F.R.S., F. R. M.S.,

Ingleside, Lee, S. E., London, England.

Hupson, Kev. ©. 1, A. M., EL. D., Bo ROM. S.,

6 Royal York Crescent, Clifton, Bristol, England.

Mappox, R.A., ... . . Greenbank, 45 Park Road, Southampton, England.

SMULE EAM UETON Ns. els. 1). Be MinSzyn ss cs ; sts Geneva,N. Ye

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SUBSCRIBERS.

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BIENNIAL INDEX.

VOLUME XVII. AND XVIII, 1895 AND 1896.

PAGE.

Acetylene Gas as the Illuminant in Photomicrography, W H. bi saa

Chicago, IIl., '96 . . .

Action of Strong Currents of Electricity Upon Nerve oles The, "95 EP

Address of Welcome, by D. F. VAN VLEET, ’95 : ‘

Address of Welcome, by C. C. MELLor,’96 . .

Address of Welcome, by Rev. W. J. HoLiLanp, 96

Address and Response, by Professor S. H. GaGE,'95 .

Address and Response, by Dr. A. C. MERcER, 96 « We mie teed ha S-

Address of the President, Professor S. H. Gace. The Processes of Life

Revealed by the Microscope; A Plea for Physiological Histology, ’95 .

Address of the President, Dr. A. CLirrForp Mercer. An Experimental

Study of Aperture as a Factor in Microscopic Vision, '96 .

Anti-vivisection : Appointment of Committee, ’96 . :

Anti-vivisection : Report of Committee, '96 . F

Astronomical Photography with Photomicrographic Apparatus, ‘Dr. A.

CuLiFFORD MERCER, Syracuse, N. Y.,°96 .

Auditing Committee, '95 ae

Auditing Committee, ’96 . :

Bacteria, On the Flagella oF Motile, ia Vv. oA - Moore, Washington, “D. e.

BELL, Ciarx, eoanmaaiatiod ae 95. :

Blood Corpuscle, Red, in Legal Medicine, Professor Moses Cc Wurtz,

New Haven, Conn., ’96. :

Brain of the Soft-Shell Turtle and English Sparrow, Comparative Mor-

phology of, Mrs. S. P. Gaag, Ithaca, N. Y., 95 :

Brain of the Embryo Soft-Shelled eee by SUSANNA PHELPS Gace,

ithaca Neve, L905. :

Bray, THomas J., ’Photomicrography, 96 Be

Buildings and Laboratories of Cornell University, "Inspection of, ‘95 hee

Buscu, Drs. F. C. and A. T. Kerr, Jr., Comparison of the Fleisch], the

Gowers and the Specific Gravity Method of pmb hr ey) the Per-

centage of Hemoglobin in Blood for Clinical Purposes, os

Business Meeting, '95 : ee eee ey ie © :

Business eicenne QOiees eet

By-Laws, ’95.

By-Laws, ’96.

Cameras, New Points in 1 Photomicrographs and Cameras, W. H. Wa.ns-

LEY, Chicago, IIl., ’95 :

Carcinoma, A Study of the Cellular Pathology of, ‘Dr. CLirForD WaLcott

KELLoGG, New Haven, Conn.,’96. - : 3 :

Carnegie Library Building, Inspection of, ‘96 . Bis :

Centering Block for Mounting, A Metal, M. PFLAUM, Pittsburg, Pa., °95

Chara coronata, The Sr eepnye Bodies of, Professor W. W. ROWLEE,

Ithaca, N. Y., 95. :

Chlorophyll Bodies of Chara cor onata, Professor W. W. Rowzee, Ithaca,

N, ¥., 95 - oe te ree eek Mr ers pee nek oes

236

179

416 THE AMERICAN MICROSCOPICAL SOCIETY.

PAGE.

Cicada See Some Peculiarities of the Mouth-Parts and Ovipositor

of, Professor J. D. Hyatt, New Rochelle, N. Y., 95... . re

CLayPoLeE, Professor EpITH jfec alee Mass., Notes on Comparative

Histology of Blood and Muscle, Gonna 49

CLayYpoLeg, Professor E. W., Akron, Ohio., On the ‘Teeth ‘of Mazodus, °96 . 146

CLAYPOLE, Professor E. W., Akron, Ohio., On the Structure of Some

Paleozoic Spines from Ohio, lOO hrm. tote, soma

Cocaine in the Study of Pond Life, S. : Conser, Sunbury, Pa, "95 2 esto

Collodion and Paraffin Embedding, S>H. ConsER, Sunbury, Pa., 95. epee

Collodion Method, Sry ON in, Professor S. H. GaGgE, Ithaca, NY

LOS buenas cd oars ei, Lah eee eee ea meee : .. 361

Committees :

Amateng COD) E ole aR es oa oe er - 94

Auditing? (0608 iin. t II

Report of Committee on ‘Re-investment of Spencer- -Tolles Fund, 96. . 31

Report of Committee on Property and Permanent Home of Society, "9631

Report of Committee on Vivisection vs. Anti-vivisection, '96 . 36

Comparative Histology of Blood and Muscle, Notes on, Professor EDITH

J. CLaypoLe, Wellesley, Mass., '96 . tetas: «)

ConseEr, S. H., Sunbury, Pa., Cocaine in the Study of Pond- Life, 9s. > e3Io

Conser, S. H., Sunbury, Pa, Paraffin and Collodion sega 95 - se Rage

Constitution, ’ 95 . Se eAbBanee we ag

Gonstitutions706%. 220. o5- Sea ace (2)

Cornell University, Inspection of Buildings and Laboratories, ’ 95 ome 47

Craiac, Dr. CHarLeEs F., Danbury, Conn, Diphtheria, Its Bacteriology, '96 271

DEFENDORF, Dr. ALLEN Ross, Worcester, Mass., Yeasts and Their Relation

to Malignant Tumors, 96. . . . 219

Diphtheria—-Its Bacteriology, by Dr. Cuarces F. ‘CRalc, Danbury, Conn, 96 271

Discussion on Paper of Mr. Priaum, "95 - a aged 36

Discussion on Paper of Mir: ScCHRENK, 95) =] 0s 3) ~ = i s.te) cree

Discussion. on’ Paper of Professor ROGERS,95. . 2: 2). =< 2 nO

Discussion on Paper of Professor HivaTT, (O5).)- (0056 =) 2 ee ene

Discussion on Paper of Dr. KrnGsBury, ’95.. . Loe LO EY alk eer

Discussion on Paper of Drs. Buscu and KERR, 95 . wet te Te Ado oe Se

Discussion on* Paper of Miss NICHOLS; 95). 7. ._% % <0 s. 0 eee mE

Discussion on Paperof Mr. WIEGAND; 2952 <=. ~ ce oe este area

Discussion on Paper of Mrs. GaGeg,’ 95 Pres sae ISS

Discussion on Paper of Dr. Moore, ’95 . ray 9. dee

Discussion on Paper of Professor Ward, "95 Lb es aoe ey

Discussion on Paper of Professor ConsER, ’95):.- ~..° oP.) 27.) eee

Discussion on Papers of Drs. Krauss and FisH,’95.........- - 65

Discussion on Paper of Mr. WaLMSLEY, '95 5 eee whe ee nan ga

Discussion on Paper of Miss LATHAM, ‘95.27. .0. <<). c) -) citecn een

Discussion on Paper of Miss CLAYPOLE,’96.... . » ob ek es

Discussion on Paper of ProrEssor GaGzE,'96. . . . . 2). '. ieee

Discussion on Paper of DR. YOUNG, QO.) =) 2) ja os ert. een

Discussion on Paper of Miss'GREEN,'96. .. .. «|. =| == ene

Discussion on Paper of MR- BRAY, 90°. 3 5257 = peste sa) cote

Discussion on Paper of Dr. MERGER) 196.0° 5) 5 3) 2) 2 ee

Discussion on Paper of Dr. Pisa, 96°. 2 2 2...) 2) eu eine en

Discussion on Paper of Miss LarHam, '96 reer 5 Oo os 8

Discussion on Paper of Mrs. GaGE,’96.. . . «Wl ES Ga ee

Discussion on Paper of PROFESSOR CLAYPOLE, 96 . MRE a oct

Discussion on Paper of PRorEssor KeLiicorr, 96. ... 2... . 26 25

Discussion on Papers of Drs. VEEDER and Krauss, 96. 26

EIGENMANN, Professor, Bloomington, Ind., The History of the Sex- Cells

from the Time of Segregation to Sexual Differentiation in Cymato-

LASEK MOS aig Ts OR er do Ue, o> MOON tee es ig ee a

THE AMERICAN MICROSCOPICAL SOCIETY. 417

PAGE.

Election of Officers for 1895-96,'95. ......- 63

Election of Officers for 1896-97, ’96. . 40

Election of Nominating Committee, '95 . 51

Election of Nominating Committee, 96. . 12

Election of Honorary Members, 96. e630

Electricity : Action of Strong Currents Upon Nerve Cells, Dr. P. A. FIsu,

iithacay Ne Ye, 495) % : 20

Epithelium, Peritoneal, of Some Ithaca Amphibia, IsaBELLa M. Green,

Akron, O., ’96. sebieplh Geena) hacia lar enrigy che S 76

Excursion on Lake Cayuga, ' 95. : 63

Excursion to Homestead Armor Plate Mills, 96 . aot

Exhibition of New Devices, ey Drs: peas and MeRcER, and Mr.

PFEAUM> 795) = a) - Romtaaets Sheeran Bro Sener cde es hand mea 73

Exhibition Microscopical, "96. sve 22

Fisu, Dr. P. A , Ithaca, N. Y., The Use of Formalin i in Neurology, ’ ‘95 5 3 Bh)

FisH, Dr. P.A., "Ithaca, Nev; ‘The Action of PORE Currents of pega)

Upon Nerve Cells, ’95 ; ore 129

ist ere. Acs bthaca,s Ne Y-.; Zoophily 1 versus ‘Homophily, 96 : 142

Fisy, Dr. P. A., Ithaca, N. Y., Notes on Technique, ’96. . . . 287

Food Supply of the Great Lakes and Some Experiments on its Amount and

Distribution, Professor Henry B. Warp, Lincoln, Neb.,'95 . j 242

Formalin as a Hardening Agent for Nerve Tissue, Dr. Wn. &: Krauss,

Buffalo, N. Y., ‘95. . Seaus

Formalin, The Use of in Neurology, Dr. P im FIs, Ithaca, N. Y., "95 319

Formalin in the Zoélogical and Histological Laboratory, Professor D. S.

KELticott, Columbus, O.,’95. . aol

Gace, Mrs. S. P, Ithaca, N. Y., Comparative Morphology ‘of the Brain ‘of

the Soft-Shelled Turtle and the English Sparrow, ’95. . . 185

GaGE, Mrs. S. P., Ithaca, N. Y.,. The Brain of the Embryo Soft- Shelled

urtle oo 2: . 282

GaGE, Professor SaMON H.., Tainea: N. Wa Present s Rddeces: The Bro-

cesses of Life Revealed by the Microscope. A Plea for Physiological

Histology, ’95. . 3

Gace, Professor SIMON ae Ithaca, N. Y. , Improvements in n the Collodion

Method, 95 . 361

Gace, Professor SIMON Henry, Ithaca, N. Y., Histology and Methods of

Instruction, ’96 . 299

GREEN, ISABELLA M., eae Ghia The feexitoneal Epithelium ah Gomme

Ithaca Amphibia, 96. 0

Hemoglobin in Blood. Comparison ‘of the Fleischl, the Gowers and the

Specific Gravity Method of Determining for Clinical Purposes, Drs.

BCG) Buscrvand Ay di Kerr; |r, uiialoy N. Wz, 195). < - - <L6S

Histology and Methods of Instruction, Professor SIMON BI Gacz, Ithaca,

INYe; C90 ©. . 299

HoLianp, Rev. W. ie Address of Welcome, ‘96 2 3

Homestead Armor Plate Mills, Excursion, ’96_ . i 5 ail

Hopkins, Dr. Grant S., Ithaca, N. Y., The ‘Lymphatics ‘and the

Lymph Circulation, with Demonstration of Specimens and Appara-

HSS OSs cree 330

Hyatt, Professor J. D., New Rochelle, N. Y., Some Peculiarities of the

Mouth Parts and Ovipositor of Cicada septendecim, iO5 ie eS A i) ie

Inspection of Buildings and Laboratories of Cornell University, "95, Peeing 47

Intercellular Spaces in the Embryos of Lrechthites hieracifolia and

Bidens cernua, K. M WIEGAND, Ithaca, N. Y., 95 - see

KELLICOTT, Dales: D.S., Columbus, O., ores in the Zodlogical atl

Histological Laboratory, ’ 95 ook

KEL.LicoTttT, Professor D. S., Columbus, oO ‘The Rotifers of Sandusky

Bay, ’96. 5 oo 3 POS. ca ONG

418 THE AMERICAN MICROSCOPICAL SOCIETY.

PAGE,

KELLOGG, Dr. CLirForRD WatLcoTtt, New Haven, Conn., A Study of the

Cellular Pathology of Carcinoma, '96. ..

Kerr, Drs. A. T., Jr., and F. C. Buscn, Buffalo, N. 'Y. , Comparison of the

Fleischl, the ‘Gowers and the Specific Gravity Method of Determining

the Percentage of Hemoglobin in Blood for Clinical Purposes, '95 . .

Kincspury, Dr. B. F., Defiance, O., The Lateral Line System of Sense

Organs in Some American SOS and a ee With Dip-

noans,’95. .

Kincsspury, Dr. B. F., Defiance, O, The Spermatheca and Methods ‘of

Fertilization in Some American Newts and Salamanders, ’95..

Krauss, Dr. WM. C., Buffalo, N. Y., Formalin as a Hardening Agent for

Nerve Tissue, ’ 95 . :

Krauss, Dr. Wo. C., Buffalo, N. Y., "A New Way ‘of Marking Objectives, ' 95

Krauss, Dr. Wo. C., Buffalo, N.Y, The ee of a Pure Water

Supply, ’96.. .

Lams, Dr. J. Meivin, Washington, D. Cc, ‘Some Methods of. Histologic

Technique, '96

Latuam, Dr. Vipa A., Chicago, nis “The Question of Correct Naming and

Use of Micro-Reagents, ° OSs Be eet Be a a5 fon ee ee Eyes

Latuam, Dr. Vina A., Chicago, Il., What is the Best Method of Teaching

Microscopical Science in Medical Schools ? Asloy Sie

Legal Medicine, The Red Blood Corpuscle in, Professor Moss C. Warts,

New Haven, Conn,’96.. .

Lymphatics and the Lymph Circulation with Demonstration of. Specimens

and Apparatus, Dr. Grant S. Hopkins, Ithaca, N. Y,’95 .

Mappox, R. L., Southampton, Eng., On the Apparent ‘Structure ‘of the

Scales of Seira buskit in Relation to the Scales of Lepfzdocyrtus

curvicollis,’96 . :

MELLOor, C. C., Pittsburg, Bae ddeess of Welcome, 96.

MELLor, C C., Organ Recital, 96 . PME kG: oc

Members East ob aks, meee Ze qo: Wem boy SPDCAO. fal Sookie See

Members, List of,'96 . ;

Mercer, Dr. A. CLIFFORD, Syracuse, N. Y., The Improved Syracuse Watch

Glass,’95. . .

Mercer, Dr. A. CurForp, Syracuse, N. ae Photomicrograph versus Micro-

photograph, "96 . ;

Mercer, Dr. A. CLIFFORD, Astronomical Photography “with Photomicro-

graphic Apparatus, ’96 . : :

Mercer, Dr. A. CLIFFORD, Syracuse, N. Y., "President's Address. An

Experimental Study of Aperture as a Factor in Microscopic Vision,

ClO ot bate BE coger

Meteoric Dust, Some Notes, Macnus PFLAUM, Pittsburg, Pa., ‘95 Siete

Methods of Instruction in Histology, Professor Simon H. Gace, Ithaca,

INV OOK tas

Method. What i is the Best Method of Teaching Microscopical Science i in

Medical Schools? Dr. Vipa A. Latuam, Chicago, IIll.,’96.. . :

Micro-Reagents, The Question of Correct Naming and Use of, Miss V. A

LatuaM, M. D., Chicago, Ill.,’95 . .

Moore, Dr. V. A. , Washington, D. ce On the Flagella of Motile Bacteria, 95

Museum of Natural History of Cornell pe ee Letter of Dr. Burt

G. WILDER, Relative to,’95 .- ae LV ie AR eats

Necrology, 96. . :

NicuHors, Mary A and Professor W. W. Rowter, ‘Ithaca, N. Y., Contribu-

tions to the Life History of Syvmflocarfus fetidus,'95. -

Objectives, A New Method of Marking, Dr. Wm. C. Krauss, ‘ Butale,

No YG" 95) «220 :

Officers for: 38qs) "95:0 eel Loa eee ede ee

Officers for, 1896;."96 245. 2075 iis 408 de aw soc hwt es. 6 a Ne nn

. 248

. 165

S1s5

. 261

THE AMERICAN MICROSCOPICAL SOCIETY. 419

PAGE.

Meotmmivecital. (C. Cx NIEPeOR OO aarti Sekar. etnek¥e ite 15S 2 12

Papers by Title, Reading of 96. . . 30

Physician and his Microscope, Dr. A. A. Youn, Newark, N. Y., 96 . 71

Priaum, Maanus, Pittsburg, Pa., A Metal Centering Block for Mounting,

Priaum, Maanus, Pittsburg, Pa., Some Notes on Alleged Meteoric Dust,

LOS)" i s95

PFLAuM, Maanus, A New Method of Making and Finishing ‘Wax- Cells, 95, 374

Plankton Hauls, A New Method for the Quantitative Determination of,

Professor Henry B. Warp, Lincoln, Neb.,’95 . .. . Retest are 255

Photomicrography, THomas J. Bray, Warren, O.,’96.. . 107

Photomicrography and Apparatus Pertaining Thereto, Systematic, James

B. SHEARER, Bay City, Mich ,’96. Skewes Sr,

Photomicrograph versus Microphotograph, Dr. oi CLiFForD Mercer,

Syracuse, N. Y.,’96.. . TST

Photography with Photomicrographic Apparatus, “Astronomical, Dr. A.

CLiFForD MERrcER, Syracuse, N. Y., 5 ae

Photomicrography, Acetylene Gas as the Hee aa in, WwW. H. ‘WALMSLEY,

Chicago, Ill.,’96. . . . 136

Respiration, Some Modifications of Stems and Roots for Purposes of, H.

VON SCHRENK, St. Louis, Mo.,'95. .. . 98

ROGERs, Professor Ww. A., Waterville, Me., A eacticd! Method of, Refer-

ring Units of Length to the Wave Length of Sodium Light, ’95 . . . 305

Rotifera of Sandusky Bay, by Professor D. S. KeLticotr, Columbus, O.,

190" ,5.2 Eara5

ROWLEE, Professor W. W., ‘and Mary A. ‘Nicuots, Ithaca, N. a, Con-

tributions to the Life History of Symplocarpus fetidus, '95 ; Si

Scales. On the Apparent Structure of the Scales of Sezra buskiz in Rela-

tion to the Scales of euaeciae curvicollis, R. L. Mappox, South-

ampton, England, ’96.. . . - 194

SCHRENK, H. VON, St. Louis, Mo., Some Modifications of Stems and Roots

for Purposes of Respiration, 95. 98

Sense Organs, The Lateral Line System, i in ‘Some American Amphibia and

Comparison with Dipnoans, Dr. B. F. Kinassury, Defiance, O., 95 . 115

Sex Cells, History of, from the Time of Segregation to Sexual Differentia-

tion in Cymatogaster, Professor C. H. EIGENMANN, cya

Ibitslin “OG.6 aoc ely72

SHEARER, James By Bay City, Mich., Systematic Photomicrography and

Apparatus Pertaining Thereto, [OOksmeoe nese ay

Soiree nsOshe ee 93

Spermatheca, The, and Methods of Fertilization in Some American Newts

and Salamanders, Dr. B. F. Kinespury, Defiance, O., ’ 95° : 261

Spines, Paleozoic, from Ohio, Structure of, Professor E. W. CLAYPoLE,

Akron, ©.,’g6. = « = Eh

Symplocarpus fatidus, Contributions to the Life History of, Professor

W. Row cee and Mary A. Nicuors, Ithaca, N. Y.,'95 . 157

A eerinine Notes on, Dr. Pierre A. Fisu, Ithaca, N. Y., '96 . 287

Technique, Some Methods of Histologic, Dra. "MELVIN re Washing-

ton yD) iGry 900 ; 291

Teeth of Wazodas: Pcoeeesan E. W. CLAYPOLE, Aeon O. ; 96 ie . 146

TuHorNBURY, Dr. Frank J., Buffalo, N. Y, The Increasing Pollution ‘of

Our Municipal Water- “Supplies, oe; Aaah en cr aRe MOGs oa 182

Treasurer's Report, 95... . Ae ieee oon Cas) Csi oo 6 94

Treasurer's Report, ’96.. . 46

Tumors, Malignant, Their Relation ‘to Yeasts, “Dr. “ALLEN Ross DEFEN-

porF, Worcester, Mass, ’96.. . . 219

Units of Light, A Practical Method of Referring. to the Wave Length ‘of

Sodium Light, Professor Wm. A. RocgErs, Waterville, Me., ’95 . . 305

420 THE AMERICAN MICROSCOPICAL SOCIETY.

PAGE.

Van VLEET, Hon. D. F., Address of Welcome, ’95

‘ bug

VEEDER, Dr. M.A., Lyons, N.Y., Public Water-Supply for Small Towns, °96 176

WALMSLEY, W. H, Chicago, Ill, New Points in emerge and

Cameras, '95.

Watns-ey, W.H, Chicago, Ill. , Acetylene Gas ; as ‘the Illuminant i in Photo-

micrography, 96 . fat

Warp, Prof. Henry B , Lincoln, Neb., The Food “Supply of the. Great

Lakes, and Some Experiments on its Amount and Distribution, '95 .

Ward, Prof. Henry B., Lincoln, Neb., A New Method for the pepe

tive Determination of Plankton Hauls, OSM

Water Supply, The Requisites of a Pure, Dr. Witttam C. “Krauss,

Biuttaloy News, GOneae

Water Supply for Small Towns, Public, Dr. M.A. VEEDER, Lyons, N. Wes 96

Water Supplies, The Increasing Pollution of Our Municipal, Dr. FRANK

J. TuHorneury, Buffalo, N.Y ,'96. :

Watch Glass, The Improved Syracuse, Dr. A. Guneoen Manonn Syracuse,

INGE,

Wax- Cells, A New Method of Making and Finishing, M. ‘PFLAUM, Pitts-

burg, Pa. OS

Waite, Professor Moses OF New Haven, Conn., ‘The Red Blood Cor-

puscle in Legal Medicine, (OO se. oa

WIEGAND, K. M., Ithaca, N. Y., Intercellular. Spaces in the Embryos ‘of

Erechthites hieracifolia and Bidens cernua, ’95 -

Wiper, Dr. Burt G., Letter of, Relative to the Museum ‘of Natural

History of Cornell University, '95 . :

Yeasts and their Relation to Malignant Tumors, Dr. ALLEN Ross DEFEN-

poRF, Worcester, Mass.,’96. . .

Youne, Dr. A. A., Newark, N. Y., The Physician and His Microscope, 96 .

Zoophily versus Homophily, by Dr. Prerre A. Fisu, Ithaca, N. Y.,'96 .

- 340

. 136

. 242

- 255

. 165

176

» 182

- 371

- 374

. 201

- 174

. 219

VPs

. 142

TRANSACTIONS

SO)! Ries

.. THE AMERICAN...

MICROSCOPICAL SOCIETY

Organised 1878. Incorporated 18ol.

EDITED BY THE SECRETARY.

TWENTIETH ANNUAL MEETING

HELD AT

Toledo, O., August 5, 6 and 7, 1897.

VOLUME XIX.

BUFFALO, N. Y.

A. T. BROWN PRINTING HOUSE.

1897.

OFFICERS FOR 1897-8.

President : Proressor D. S. Ketiicott, Pu. D., F.R.M.S Columbus, O.

Vice-Presidents : Moses C. WuitE, M.D... .. .. New Haven, Conn.

VERANUS) A. Moore, ‘Me D: 2 3% 5) oe 2 thaeaseNeee

Secretary - Witutam C. Krauss, M. D., F.R. M.S .. . . . Buffalo, N.Y.

Treasurer: MAGNUS PFEAUM .«->- 4. + -- 5 . =... - = hittsburp years

ELECTIVE MEMBERS OF THE EXECUTIVE COMMITTEE.

DE; Hosac M.D, “BERN eS (ese sae he ne tee oe 9 ee em

IR ABERDEIN Vie) akiee ives Vicon sucm Cenclun aera ment enn: . . . syracuse, N. Y-

Epitu J. Craypote, Po. D..M.S ......... . .- . Wellesley, Mass.

PAST PRESIDENTS.

Ex-officio members of the Executive Board.

I. Lok. He Warp; MD: FoR M&S; .of roy; Ni ey.,

at Indianapolis, Ind., 1878.

2. R.H. Warp, M.D., F. R. M.S., of Troy, N.Y,

at Buffalo, N. Y., 1879.

3.. H. Lk, Smiru, LL-D., FR. M:S..of Geneva, N.Y,

at Detroit, Mich., 1880.

4. -J. D. Hyatt, F. RM. S, of New York City,

at Columbus, O., 1881.

5. Geo. E. BiracxuHam, M. D., F. R.M S., of Dunkirk, N. Y.,

at Elmira, N. Y., 1882.

6. ALBEertT McCatra, Po D., F R.M. S, of Fairfield, Ia,

at Chicago, Ill, 1883

4. J. Dy Cox, LL D., FR M.is:, of ‘Cinemnati, 0%,

: at Rochester, N. Y., 1884.

8: Be Lk: Smite, Ley DERM (S; of Geneva, Naya,

at Cleveland, O., 1885.

9. T. J. Burritt, Pa. D., F. R. M.S., of Champaign, IIl.,

at Chautauqua, N. Y., 1886,

10. Wn. A. Rocers, A. M., F. R. M.S., of Waterville, Me.,

at Pittsburg, Pa., 1887.

it, = Ds S.KELEICONT, PHD. Eb. he Mi. S.-0f Columbus. O)-

at Columbus, O., 1888.

12. Wm J. Lewis, M. D., F. R. M.S, of Hartford, Conn.,

at Buffalo, N Y., 1889.

in GEO. arene, M.D ishak: Ma.S) ot buttalo, Nave,

at Detroit, Mich , 1890,

14. Frank L. James, Pu. D., M. D., F.R M.S, of St. Louis, Mo.,

at Washington, D. C., 18o1.

15. MarsHaLit D. Ewe tt, M. D., F. R.M. S., of Chicago, IIl.,

at Rochester, N. Y., 1892.

ro, ~ Jacos™D. Cox, Lu -D 7 Ro M-S., of Cincinnati, O.,

at Madison, Wis., 1893.

17. Lester Curtis, M D., F. R. M.S., of Chicago, IIl.,

at Brooklyn, N. Y., 1894.

18. Srmon Henry GaGE, B. S., of Ithaca, N. Y.,

at Ithaca, N. Y., 1895.

Ig. A. CLirFoRD Mercer, M. D., F.R. M.S, of Syracuse, N. Y.,

at Pittsburg, Pa., 1896.

20. E. W. Craypore, B.A., D.-Sc:, (Lond.), F. G. SS. L. E.& Ay) Akrong@r

at Toledo, O., 1897.

_ The Society does not hold itself responsible for the opinions expressed by members in

its published Proceedings unless indorsed by a special vote.

PROCEEDINGS

The American Microscopical Society.

Twentieth Annual Meeting, Held at Toledo, O., August 5, 6 and 7, 1897.

THE PRESIDENT’S ADDRESS.

MICROSCOPICAL LIGHT IN GEOLOGICAL DARKNESS,

Ee We CLAYPOLE, BA) D2Ses(Eond)82G. SSFELE. &A., Akron;.@2

In appearing before the American Microscopical Society

on this occasion, to deliver the usual annual address, I feel

that it will be appropriate that I choose my subject and

material from the field with which lam most familiar. Itis not

probable that I can tell anything new or important to those

members who have devoted much time and thought to the

structure and improvement of the microscope. They are

more familiar with these matters than I am, and into this field

it would be presumptuous in me to enter. Nor is it likely

that I can give many of you any instruction in microscopical

technique. With me the microscope is and has always been,

ever since I began to use it for research, an implement much

employed at times for the prosecution of my work in teach-

ing and in investigation, and then laid aside until another

occasion called it forth. I can make no profession to being

a technical microscopist.

4 EDWARD W. CLAY POLE :

I could not hope to rival or surpass the address of my

predecessor in this chair on the limits of the visible or many

of the interesting and laborious investigations which have

formed the topics of yet earlier presidential discourses. The

purpose of the Society is, in my opinion, better served by

bringing forward something specially belonging to the field of

investigation, in which the speaker is at the time and has,

perhaps for many years, been engaged. By so doing the

danger of repetition and of overlapping is avoided, for the

fields of labor are so numerous and so different that it can

scarcely happen that two successive presidents will be

employed in the same department. Another advantage is

also secured by the adoption of this plan. His fellow-mem-

bers are, so to speak, personally conducted by the speaker

over fields which they would otherwise seldom or never visit,

and are made acquainted with work and results of which they

must, but for some such opportunity, remain ignorant

through lack of time to do the necessary reading and study.

The field of nature, which has more particularly engaged

my attention—the field of geology—is of immense extent

and borders on those of zoology and botany, into both of

which the geologist is compelled to make long and frequent

excursions in order to gain the knowledge and experience

that will alone keep him from useless labor and erroneous

results in his own department.

I will, therefore, ask you this evening to accompany me

on a short trip through a part of my own favorite field ‘of

nature, where I will be your guide and Cicerone, and where

I trust that you will all find something worth the time and the

patience which your presence here this evening shows that

you are willing to devote.

The portion of the geological field which I have chosen

for our excursion is that in which the microscope is the most

important instrument of investigation. It is, therefore, one

in which the geologist and the specialist in microscopy can

both feel an interest. It is also one in which this engine of

THE PRESIDENT’S ADDRESS. 5

investigation has but recently been employed to any great

extent, and may, I hope, to some of my hearers possess a

little of the charm of novelty.

I have entitled the address Microscopical Light in Geo-

logical Darkness, but its scope would be equally well expressed

had I called it The Microscope in Geology.

To the geologist the year 1858 is a memorable epoch in

the history of his science. At that date the now veteran

worker, Mr. H. C. Sorby, of Sheffield, England, published his

first paper on the Microscopic Structure of Rocks’, in which he

showed the vast possibility that the new power had brought

within reach, or to maintain our figure, the great extent of

the dark unknown which the new light would illuminate.

Passing by for the moment the immediate subject of that

memorable essay, to which I will return anon, I must explain

that Mr. Sorby was the first to investigate the microscopic

structure of rocks by means of thin sections. ?

The aid which the lapidary could give had not previously

been asked in this work. It had not been considered likely

that any mysteries would be revealed by a study of what

1. Dr. H. C. Sorby inaugurated his year of office as president of the Sheffield Literary

and Philosophical Society by giving an address upon a half century spent in scientific work.

During this time he has published more than one hundred papers. The earliest was in 1847.

In 1849 he prepared the first transparent microscopical sections of rocks, on which he issued

a paper in 1850, wherein most of the modern methods were adopted. From this subject he

was led on to that of meteorites and meteoric iron. Then he undertook an investigation of

the microscopical structure of iron and steel by new methods and with new illuminators,

This led him to the invention of the direct-vision spectrum-microscope.and other apparatus.

From this he passed on to study the coloring matters of animals and plants. Thirty years

ago he received the Wollaston medal from the Geological Society. The Dutch Academy of

Science awarded to him its first Boerhaave go!d medal, and the Royal Society conferred on

him a gold medal in 1874. Oxford gave him an honorary degree of LL. D.—Nature, February

11, 1897

2. It is scarcely necessary for me to explain to any members of the Society the methods

of petrography. Thin chips or sawn slices of the minerals are smoothed and polished on

one side, cemented to a glass slide and then smoothed and polished on the other. Few min-

eralS are So opaque as to refuse to become transparent or translucent. The introduction of

the new abrasive substance, carborundum, has proved of great value to the petrographer,

enabling him to reduce the cost by using this powder instead of diamond dust.

6 EDWARD W. CLAYPOLE:

were classed as the metamorphic rocks. But the collateral

advance in various departments of physics had provided new

machinery and established new positions, and Mr. Sorby

boldly advanced to the examination of these polymorphic

masses, which had long figured as granites, gneisses, syenites,

greenstones, etc., and regarding which diverse and contra-

dictory views had been held. The art of cutting and grind-

ing thin transparent slices of these minerals, introduced by

Mr. Sorby, has now been developed so as to have become

one of the most important aids to microscopical geology, and

the dark and tangled problem of the crystalline rocks and

crystalline schists, when some day solved, will be solved

largely by the invaluable assistance which this device has

bestowed upon the investigator.

As an example of what I mean, let me adduce the case of

certain quartzites, supposed by some to be of non-sedimen-

tary origin and therefore to differ radically from other quartz-

ites and sandstones. I should explain that to the geologist

a sandstone is nothing but an ancient seabeach or lakeshore

and the sand is the material of more ancient cliffs and bluffs

which have been broken up by the waves and ground down

by long-continued dashing on the shore. Every grain of

these sandstones shows its origin by its form. Itis worn and

rubbed till all the points and edges have been rounded off

and it is in fact a microscopic pebble. Sandstones are the

monuments of extinct geography and, though now far inland,

show us where, in times gone by, the land and water met.

The geologist can almost hear the roar of the waves as he

gazes through his microscope on the tiny quartz grain that

has suffered such tribulation, but which has endured in con-

sequence of its hardness—a case, we may presume, of the

survival of the fittest. He is reminded of Tennyson’s lines:

Here rolls the deep where grew the tree

O earth, what changes thou hast seen

Here where the long street roars hath been

The stillness of the central sea.

THE PRESIDENT’S ADDRESS. 7

But the sandstones to which I allude showed characters

which did not agree with those usually seen. The grains did

not appearto be rounded. They seemed to possess the sharp

and angular form of quartz-crystals, hence they were claimed

as products of igneous, or at least of metamorphic action.

But after grinding down thin slices and subjecting them to

microscopic examination it was soon proved that every grain

of the rock had once been as weil rounded as were those of

the most typical sandstone, and that the deceptive appear-

ance was due to a secondary growth of quartz since the

deposition of the sand. So obvious was this that the worn

outline of the primitive grain could be readily traced by a

thin film of limonite encrusting it, outside of which the new

growth had taken place. This was clearly demonstrated in

the case of a quartzite from Wisconsin by the late Prof. R.

D. Irving, who published a striking illustration several years

ago, where the solidification of the rock, converting it from a

sandstone into a quartzite, had been induced by a secondary

growth of younger quartz, which, acting as a bond, had filled

up the interstices and cemented the whole into one hard,

solid mass of silica.

In consequence of these discoveries all such sandstones

and quartzites were removed from the Archean or igneous

domain and established permanently as parts of the great

system of stratified rocks, many of them being among the

most ancient of the class.

Yet a further step followed. The microscopist has at his

command another instrument, sometimes more effective than

his special favorite, and when combined with this, adding

immensely to its power. The polariscope aids the micro-

scope and the polarised beam often reveals what would other-

wise remain unseen. The structure of most crystals is such

that they possess different moduli of optical elasticity. That

is to say, they transmit light with different velocity in differ-

ent directions. This is very strongly marked in some sub-

stances, of which quartz is one. The consequence is that

8 EDWARD W.. CLAYPOLE:

when a polarised beam passes through a thin plate of one of

these minerals and afterward through the analysing nicol

interference is produced, part of the pencil is extinguished

and the remainder of the rays exhibit the magnificent spectral

tints which are nature’s language in revealing her secrets.

The slide which, under the microscopic objective alone, shows

merely the outlines of the structure glows

under this light with a splendor of color

only to be rivaled by the spectrum itself.

Every crystal, with few exceptions,

comes out in the tint due to its position

in the rock and changes this tint with

kaleidoscopic quickness and beauty as

the analyser revolves. Translating this

color-language of nature and applying it

to the sandstones in question we find

that it tells us the direction of the crys-

tallographic axis, and therefore enables

us to recognise the position of every

quartz grain. By so doing we learn that

the rounded and worn fragment has

grown just as broken crystals grow and

SAND-GRAIN WITH renew themselves in our laboratories,

SECONDARY QUARTZ. and that the secondary quartz taken on

Fig. 1.—Showing the worn during the rejuvenescence of the enystal

grain of sand and its crys-

fallographic axes,around-- hac been taken on accurately on the orig-

which secondary quartz

nual the cevcalos whe inal lines. In other words, the part of the

Re eee quartz-crystal outside the zone of limon-

ite is oriented optically and crystallographically in exact agree-

ment with the original worn sandstone grain within that zone.

The same law of growth that dominated the young crystal sur-

vived its severe attrition and partial destruction and at length,

after ages of rough usage and wear and tear on a sea-beach,

resumed its sway when conditions again became favorable, and

showed its sustained supremacy by dominating the subsequent

accretion of quartz when crystalline growth again began.

THE PRESIDENT'S ADDRESS. 9

But in another direction also the geologist has profited

by the light shed abroad over his field by the microscopist.

The study of these thin slices by the aid of polarised light has

revealed other facts of immense significance to the petrologist

and as unexpected as they are significant.

It is among the ancient rocks of our earth that the micro-

scope has won and is winning its greatest triumphs. ‘ In that

wilderness of Archean crystallines, where few dared hope

ever to find any limits or boundaries—that sea without a

shore—that worse than Serbonian bog in which to plunge

seemed certain oblivion, ‘‘wherein length, depth and height

and time and space were lost ’—here the microscope is reveal-

ing limits—is providing a compass—is pointing out solid

stepping places where safe footing may be found and steady

progress made. Those who are not practical geologists can-

not realise the immense difficulty of studying the massive

so-called primary rocks. The gneisses and granites and

crystalline schists that underlie the stratified sandstones,

shales and limestones have hitherto been an insoluble enigma.

Were they of igneous or aqueous origin? Were they part of

the original crust as it consolidated from fusion or were they

later deposits, subsequently altered and crystallised? Was

gneiss essentially and always an Archean rock, or was gneiss

a product of any age under certain conditions? These ques-

tions divided the geological world and agreement seemed

impossible. The long conflict between the Plutonists and

the Neptunians was not more severe or more hopeless.

The importance of the problem is evident when we con-

sider the immensity of these rocks. Look, for example, at

the huge mass of gneiss which composes the surface rock over

a large part of Canada. Stretching in a vast curve from the

Atlantic coast of Labrador through Quebec and Ontario north

of the Great Lakes and thence away toward the Arctic ocean

and forming the basement of the whole geological column, it

has been well named by the Canadian geologists the Funda-

mental Gneiss. Of immense, but unknown, thickness it

IO EDWARD W. CLAYPOLE:

presents a monotonous complex of crystalline minerals, among

which quartz, orthoclase, mica and hornblende are by far

the most abundant and characteristic.

But whether these are metamorphic sediments or the pro-

duct of a liquid original magma was an unsolved problem.

And no method of reaching a solution was found until the

new science of petrology supplied it. Within the past few

years great progress has been made in the investigation.

Thin slices of this and other similar gneisses have been cut

by the thousand in the different laboratories of the world.

Laid on the stage of the microscope between the crossed

nicols they have supplied strong and unexpected evidence.

On one may be seen a crystal of quartz in good condition,

giving extinction of the polarised ray at once and complete

in all parts at the same instant and angle. In another is

found a similar fragment in the form of a thin plate, whose

irregular extinction, though slight, shows plainly that some

great change has come over it since it was enclosed in its

matrix. The original crystal has been in some cases flattened

down so as to form a thin lamina in which all the regular

structure and the previous molecular arrangement of the

crystal have been abolished. The previous axes of optical

elasticity no longer betray their symmetrical positions by

uniform interference-colors. They are broken up and dis-

placed as though some violent disturbance had happened to

them. In like manner acrystal of plagioclase felspar may be

found in which parallel planes of granular felsite, intersect-

ing the mass, are revealed by this delicate test. Similar

phenomena appear in the case of hornblende. The crystal

does not show the original sharp outline and definite form,

but is flattened, distorted, often fractured, and not unfre-

quently a line of particles is seen tailing off from it in one

direction like the wash from a rock exposed to the action of

a stream of water. Mica, too, exhibits like appearances, and

the particles of an original crystal will often form a distinct -

black layer to a short distance to the leeward, so to speak,

THE PRESIDENT’S ADDRESS. I!

of the remaining portion. In this way the so-called ‘‘ augen-

gneisses” of the petrologist have been formed. Thus the

action of all these minerals, and the same is true of others,

indicates the action of some secondary force which has caused

momentous and destructive changes in the original crystals.

Data, such as these, undiscoverable by the naked eye,

come out in brilliant colors and sharp outlines on the stage of

or 12

Zeal O

Pe ie

* mS Ad Pee

a 54

Be g Ay ine. oy b

eet teats eer Co

PLAGIOCLASE CRYSTAL— PARTLY CRUSHED.

Fig. 2.—Showing the remains of a crystal of plagioclase felspar in the middle, with crushed

felsite above and below and partly formed layer of the same through the middle. The

white portion represents a region where crushing had commenced, but ceased on relief

of pressure.—From Dr. Adams’s Report, Geo]. Surv. of Canada. 1896.

the polariscopic microscope, and it is only necessary to learn

‘to read the hieroglyphics of nature in order to translate them

into the language of man. When this is done we find that

they all have one bearing and point in one direction. They

speak all with one voice and their words are clear and

emphatic. The injuries which the crystals have suffered,

their consequent irregular action on polarised light, tell us

plainly that they have been subjected to the action of some

resistless force since their formation, and that this force has

12 EDWARD W. CLAYPOLE:

produced earth-movements whose effects are shown in the

crushed and mangled condition of the component mineral

crystals.

These destructive changes could not have taken place

when the rock was in a liquid state. Only after consolida-

tion of the magma and the crystallisation of its component

minerals could their fracture and crushing become possible.

Evidently, then, these gneisses are the product of great heat

and this, with their immense extent, prevents our regarding

them in any other light than formations of very ancient date

—genuine Archean rocks.

It may be difficult to believe that a fragment of so hard

and brittle a mineral as quartz could, by any force whatever,

be flattened out into a thin plate, but the evidence allows no

doubt on this point. Under these terrific pressures the

crystalline structure of the gneisses has broken down and a

granular condition has resulted. Crystals of quartz have

been crushed into quartzite and crystals of felspar into felsite.

Hornblende, being tougher, has been squeezed and flattened

down into thin plates and a laminated structure developed

thereby in the rock-mass, while mica, often the product of

these pressures, has in like manner contributed to render the

previously compact mass schistose and flaky.

Beside these manifest indications of excessive force

exerted on the crystals there are others less distinct, traces

of incipient yielding—molecular displacements—‘“ strain-

shadows,” so to speak, which betray the intensity of the

compression to which this fundamental gneiss of Canada has

been subjected. The crystals have been caught, as it were,

in all stages of their crushing, and the record of the process

is complete.

It is not our business this evening to ask the causes of so

mighty a force exerted within the earth or to answer our

own question. To the physicist the problem presents no

great difficulty. But looking at these thin sections and

realising their unanswerable testimony, the geologist almost

THE PRESIDENT’S ADDRESS. 13

feels the fearful strains which have torn asunder, as it were,

the very fibers of the solid crust. As he looks at the wounds

and rents in these crystals he sees them laboring to adjust

themselves to the pressure and hears the sounds of the crack-

ing and crushing which follow their failure to comply instantly

with the peremptory demand. The slightest variation in

pressures so enormous must be followed by movement and

this variation of pressure must have been incessant. Hence

the crushed condition of the crystals and the evidence of

continual ‘‘creeps” in the gneiss in order to adjust itself

and maintain its equilibrium of the mass. Hence, also the

geologist realises the continuity of the internal mass and the

absence of joints and fissures. He is convinced that at the

depth of a very few miles no cavity in the crust can pos-.

sibly exist, for under a gravitational force so intense, the

whole mass, of whatever consisting, must be plastic as wax,

every incipient cavity being filled, so to speak, before it was.

opened.

Yet more than this has been revealed to us. Not only

have the separate crystals of the rock thus given way under

the enormous earth-strains, but the mass, as a whole, during

and after crushing, has flowed like a liquid in the line of least

resistance. Hard granite and tough diorite have alike yielded

and have been squeezed like putty so that flow-lines have

been developed and a schistose or slaty structure produced.

Tresca’s well-known experiments many years ago con-.

vinced us of the possible flow of refractory substances under

adequate pressure. Even cold iron was squeezed out as wax.

But the materials with which Tresca worked were not brittle.

like crystals of quartz, felspar, etc. Tresca also had not in

his power the pressures that the geologist can demand or the

long zons that geology can summon. Grant these and the

microscope and the polariscope combined give us evidence

that cannot be gain-said, that even these brittle minerals of

the great fundamental gneiss of the Canadian highlands have.

been squeezed out until their constituent particles, in the.

14 EDWARD W. CLAYPOLE:

effort to escape the tremendous pressure, have slid over one

another as those of a viscous mass. Yet though compelled

to move because the equilibrium was disturbed, they were

unable to move out of their spheres of mutual cohesion so

that, though sheared, their continuity has not been destroyed.

The gneiss or the granite has crumbled, but the crumbs

cohere and it is one mass still though its form is changed.

One step farther the geologist can safely advance by

inference. Strains so enormous could not be developed at

or near the surface of the globe. Relief would soon be found

there by upward movement. The pressure indicated by our

polariscope must have been deep enough to be produced in

great part by the weight of the overlying strata. What

depth would be required for this purpose it is not possible yet

to determine with exactness. But as we have in Pennsyl-

vania and elsewhere strata now at the surface which were

once certainly several miles below it, and as these strata

show not the least sign of having undergone any such treat-

ment as that which I have described, it is safe to conclude

that the rock now forming the surface of the Laurentide

Mountains must once have lain at a still greater depth. Such

possibilities are not easily realised unless the mind dwells on the

thought. That the now bare gneissic rocks of Canada were

once covered with a thickness of many miles of the same

material, is a daring deduction from the study of a micro-

scopic slide only one hundredth of an inch thick and less

than a square inch in area. But denial is more daring still.

As Playfair wrote in his celebrated essay on the Huttonian

theory: ‘‘Reason can sometimes go where imagination

dares not follow.”*

1. Not to carry this argument farther in the text I will add here that, inasmuch as it is

quite certain that no such mass ever existed at any one time on the Laurentide area, it is

necessary to adopt the view that a slow elevation of the region has been in progress through

geologic time and that elevation and subsidence have approximately equalled and counter-

acted each other ever since the movement began. Resting on this, some geologists have

gone farther and have taught that the mountain masses of the earth are such in consequence

of the inherent levity of their materials, and that, on the other hand, the ocean abysses are

sunk because their floors consist of matter inherently denser and therefore floating lower in

the viscid core.

THE PRESIDENT’S ADDRESS. 15

III.

But even this is far from acknowledging to the full the

debt of geology to the microscope. Indeed, it seems as if

the future were more charged with promise than the past with

performance. In another part of the field the same veteran

observer and worker has led the way and new prizes have

fallen to the lot of him and his followers.

Gems and other crystals had long

been known, especially since the time of

Brewster, to contain minute cavities

partly or entirely filled with a liquid

whose nature was unknown. But by the

study of a few specimens Sorby suc-

ceeded in determining it in several cases.

Among these was one which deserves

to become classic on account of the

peculiar advantage which it gave to our

pioneer in the investigation. This was,

indeed I hope I may say it zs, though I

do not know its present abode, a sap-

phire containing a cavity of a tubular

form. It was so regular in its bore that

it served the purpose of a natural ther- :

mometer, and by its use Mr. Sorby SAPPHIRE WITH

reached a conclusion at once surprising RAE RE

and important. I should mention that Fig 3>Mr, Sorby's micro-

this little thermometer was one-fourth ak apy een ee

of an inch long by about one-eightieth = ““P°™Uoxi¢e

of an inch in diameter, atruly microscopicalinstrument. It is

represented, greatly magnified, on the diagram Fig. 3. On

experimenting with this little instrument Mr. Sorby found that

the liquid, which, as shown, filled one-half of the Cavity at

ordinary temperatures such as 50° F., expanded so rapidly

that its volume was doubled and the cavity was full at 89° F.

This increase of bulk within so narrow limits of temperature

16 EDWARD W. CLAYPOLE:

at once excluded all ordinary liquids, and by further investiga-

tion and comparison Mr. Sorby was able to decide that the

substance was nothing less than liquid carbonic acid, the only

known liquid whose rate of expansion was equally great.

Here was a solid fact contributed by the microscope toward

the solution of some of the difficult and complicated prob-

lems presented by the physics of the earth’s crust, and,

again, we shall find that from this study of a drop of liquid

almost infinitely little, contained in an instrument equally

minute, may flow results of great moment and far-reaching

consequence. It is not the size but the solidity of the

premises that authorises the conclusions. Granting, as we

must, that the little drop is carbon-dioxide in the liquid

form, we can safely advance by reasoning on the known

properties of this substance somewhat as follows :

The critical temperature of carbon-dioxide is about 88° F.

(87.6°), that is tosay, above this it exists only asa gas, and can

by no pressure be liquefied. Now it is in the highest degree

improbable that at the time and in the conditions when the

crystalline rocks were formed the surface of the earth was

below this point. On the other hand, we may confidently

rely on its having been far above this critical temperature.

Obviously then the carbon-dioxide must have been sealed up

in the crystals in a gaseous state—a bubble of carbonic anhy-

dride. Here the problem becomes indeterminate. Both

the original temperature and pressure are unknown. But

arguing from what we know of the physics of this substance

we may deduce the following conclusion: At present ordin-

ary temperature, 50° F., the pressure in the microscopical

registering thermometer of Mr. Sorby, must amount to about

forty-eight atmospheres or 720 pounds on the square inch.

This little instrument was exactly filled at 89° F., very near

the critical temperature. At this point the minimum pressure

which will enable the carbonic anhydride to retain the liquid

state is seventy-three atmospheres or I,100 pounds on the

squareinch. Consequently, if asinevitable, we assume a higher

THE PRESIDENT’S ADDRESS. 7.

temperature than 88° F. for the globe at the time of the crys-

tallisation of the minerals, we must also assume a higher

pressure than seventy-three atmospheres as one of the con-

ditions prevailing during crystallisation.

This, however, is doubtless far too low for both. Instead of

88° Mr. Sorby and others consider the temperature of con-

solidation to have been nearer 700° F. Mr. J. C. Ward, a

few years ago, following in the footprints of Mr. Sorby, carried

his work a little farther. Assuming his datum of 680° F. as

the temperature of crystallisation of the minerals, he shows

that the corresponding pressure was not less than twenty-six

tons, or 3,500 atmospheres on the square inch, and that these

microscopic flasks must have been charged with their effer-

vescing contents under that enormous compression.

This is equal to the weight of a mass of overlying strata

52,000 feet thick. It is not right, however, to attribute the

whole of this to the weight of overlying strata. There is no

doubt that it is a resultant of this and the violent lateral com-

pression-to which the contortion and folding of the gneiss is

due. The latter is probably the larger of the two compon-

ents. Mr. Ward’s conclusion is that the granite of Skiddaw,

in England, was formed at least six miles below the sur-

face, a depth at which the temperature is normally very near

Mr. Sorby’s datum of 680° F.

This is surely a vast deduction from data, microscopically

minute, and seemingly insignificant. But insignificant as one

of these ‘‘crystal flasks,” as they have been aptly called, may

be, we are not dealing with one alone but with vast numbers,

for investigation has revealed them by myriads and by

millions, and not in gems only, but in other crystalline min-

erals. In size they range between the one-thousandth and

the fifty-thousandth of an inch, but they are so multitudinous

as often to impart a white tint to the crystal, and many

specimens of milky quartz owe their whiteness solely to the

presence of these innumerable bubbles. In some of the

Cornish granites the cavities make five per cent. of the vol-

18 EDWARD W. CLAYPOLE =

ume, and yield four pounds of the liquid to every ton of the

rock.

Mr. Ward says: ‘‘Such is the minuteness of these cavi-

ties and their number in many cases, that more than a

thousand millions might be contained easily within a cubic

inch of quartz.” We shall presently quote another writer

giving the same testimony.

LY.

I must here digress for a short time from the main line to

trace a tributary that meets it at this point and whose course

it is necessary to have in mind in order to develop the argu-

ment. The geologist, regarding the past history of the

globe with a critical eye, has long been amazed at the vast

masses of mineral fuel—coal, petroleum and gas—which he

finds accumulated in the crust and especially on one horizon.

The carboniferous system, with its huge stores of free car-

bon, the chief and almost the only resource of the world at

present for heat and power, and its hope for the future are

to him a standing enigma. The botanist assures him that

all has been extracted from the atmosphere by the agency of

green plants, under the stimulus of sunshine. No other pro-

cess is known whereby this precious element can be severed

from its compounds and isolated in free form in any appreci-

able quantity. Indeed its separation in the laboratory is a

somewhat difficult and refined experiment. But this assur-

ance of the botanist darkens rather than clears the enigma of

the geologist. Relying with confidence on the botanical

principles of his brother-student, which are confirmed by so

many concomitant proofs as to be quite unassailable, such as the

vegetable structures, leaves, stems and fruits found in the

coal, he is yet unable to see where these plants obtained so

vast a supply of carbon. From a careful quantitative study

of the atmosphere he learns that the sum total of this element

therein contained is vastly less than that which now lies

THE PRESIDENT’S ADDRESS. 19

buried in the earth, so that to accumulate another stock of

mineral fuel equal to that which we are now using so freely

and squandering so recklessly, would be an impossibility.

The material is not present in the atmosphere, and what is

not there can not betaken away. Without troubling you here

and now with the calculations, I will merely give sufficient

results to establish my statement and to enable you to follow

me with confidence. The whole amount of carbon in the air

to-day, in the form of carbon-dioxide, does not exceed 150 to

200 cubic miles—a sufficiently large amount you are ready to

say when you try to realise what it expresses. A single

cubic mile of coal almost passes comprehension. The world’s

entire annual consumption does not exceed 350,000,000 tons,

so that one single cubic mile, or 7,000,000,000 tons, would

suffice to supply us all for twenty years. But the stock of

coal and the like, actually in the ground, far exceeds, as I

have said, even this enormous figure. To attain anything

like exactness in such data is manifestly impossible, but we

cannot assign to the world’s store of mineral fuel, or the coal

contents of our coal fields, oil fields and the like, a less

amount than 2,000 cubic miles at the least, or about ten times

what could be obtained fromthe air. Here lies the enigma,

and, as you see, the botanist has not furnished any interpre-

tation of it.

It is easy to say, as many have said, that there wasa

larger supply of carbonic acid in the atmosphere then, than

there is now. This is cutting rather than untying the

Gordian knot. Perhaps it was so. The explanation is

plausible. But the plausible in nature is not always or

usually the true.

Time will not allow a full discussion of this topic this

evening. It must suffice to indicate, in a general way, the

reasons which preclude us from accepting the reply as good

and sufficient.

In the first place, let us consider the demand of the geolo-

gist. We have mentioned the coal beds, the oil and the gas,

20 EDWARD W. CLAYPOLE:

but these are far from being all that he requires. There are

in the earth huge beds of black shale, holding often from 5

to 15 per cent. of carbonaceous matter. This far exceeds

the mass of the coal and we may safely put the figure up

from 2,000 to 20,000 cubic miles. Alexander Winchell’s

total is nearer 30,000. Then the vast stores of peat and the

whole animal and vegetable creation, or at least the carbon

which they contain, must be included, and this defies exact cal-

culation. Lastly, the mass of coal that has been destroyed

by erosion must be added—small though it be beside the

vast total. Considering all these it seems perfectly safe to

set down the mass of unoxydised carbon in the earth’s crust

at 50,000 cubic miles, or 250 times as much as that now

existing in the air—a proportion of IO per cent.

Facing this fact the botanist is scarcely willing to admit

that plants could flourish insucha medium. Ferns and their

allies have been grown in cases charged with an atmosphere

containing 10 per cent. of carbonic anhydride, and possibly

so large a proportion may have been consistent with the

existence of the cryptogams of the early eras. Botany can-

not give an absolute denial. Experiments on this point are

few and not very definite. Prof. Daubeny, of Oxford, stated

nearly fifty years ago, in a paper read before the British

Association in 1849, that ferns and their allies cannot bear

more than IO per cent., but could exist in an atmosphere

containing 5 per cent. of carbon-dioxide. Prof. Boussin-

gault reported, in 1864, that different plants flourish best in

atmospheres ranging from 8 per cent. downward. We may

therefore infer that the above requirement of the geologist is

close to, if not above, the limit of tolerance of plants allied

to those by which the mass of our coal was made, and that

on this ground it is scarcely tenable.

On the zoological side the evidence is also uncertain.

Some of the lower animals, such as fishes and amphibians,

are tolerant of a far larger amount of carbon-dioxide than

can be endured by the higher groups. But it can scarcely

THE PRESIDENT’S ADDRESS. 21

be probable that even they could live in an atmosphere con-

taining as much as IO per cent.

However, setting aside both these as inconclusive, a

physical objection remains to be considered of more serious

import. By calculation we find that the conversion of this

mass of carbon into carbon-dioxide would absorb all or

nearly all the oxygen in the air and leave it devoid of that

essential element. We may, therefore, safely assert that

whatever the earth’s atmosphere may have been in very early

times, the carbon now in the crust cannot have existed as

carbonic acid in the atmosphere at any one time since animal

life began.

Returning, then, to our former ground we see that, without

dogmatising on the primitive atmosphere, we are unable to

accept this plausible explanation as a good and sufficient

solution. We cannot hypothecate a sufficient capital stock

of carbon to meet the immense and continuous drafts that

have been made upon it.

So strongly did one of our most able chemical geologists,

the late Dr. Sterry Hunt, feel this difficulty, that he was

driven to make the suggestion that the earth had picked up

the needed material from the space-realms during her annual

and secular journeys—a remark which Alexander Winchell

says is ‘‘highly suggestive.” Butif wecan realise the figures

of some modern molecular physicists regarding space we can

hardly entertain the suggestion, for they tell us that in the

interplanetary regions there is only one molecule of any kind

in 10%'4 cubic miles of space. In such an absolute, awful

solitude, the earth can surely not have been able to gather

up the needed carbon-dioxide, though she had sought it from

pre-Cambrian times down to the present day.

V..

But here the microscopist comes upon the field and offers

his services in the cause of peace. In diplomatic language,

he proposes to act as mediator. He points out, as I have

22 EDWARD) W. GCLAYVPOLE:

already said, the minute cavities existing in the crystalline

rocks and shows that in them is hidden a store of carbonic

acid, hoarded, as it were, in the pockets of mother earth,

infinitesimally small but infinitely numerous, and he suggests

that possibly here a source may be found from which the

geologist may get his coal and the botanist his carbonic acid,

without alarming the zoologist for the safety of his animals.

He shows that on this view it is no longer necessary to

assume its presence in the atmosphere all at the same time.

Instead of this he suggests that it may have been, and prob-

ably was, set free almost atom by atom as the crystalline

rocks yielded to erosion and these ‘‘ sealed flasks” were, one

after another, burst open by the pressure within.

At first blush we may be disposed to laugh at the sugges-

tion and to deem such microscopical contributions of small

comparative value when so vast a demand is made. But it

is well to recollect that ‘‘many a little makes a mickle.”

Let us look at the matter quantitatively for a moment, for

here must lie the crucial test. If our theory fail here it fails

altogether, though if it pass this test its ultimate success is

not hereby assured.

Since the investigation by Mr. Sorby, to which I referred

at the outset, little advance has been made until quite

recently, when a stimulus was given to new experiments by

the marvelous discovery of argon in the atmosphere. The

distinguished chemists who were engaged in that most

remarkable investigation turned their attention to the gases

contained in various minerals, among which were those of

the crystalline rocks. And ina paper recently read before

the Royal Society (March, 1897), Professor W. A. Tilden

stated, as the outcome of some work on quartz, felspar, and

the other constituents of granite, gneiss, gabbro, schist,

basalt and other minerals, twenty altogether, from different

horizons and widely distant localities, that they all yielded

gas in which hydrogen is the preponderating element.

Next to hydrogen the most abundant is carbonic acid. And

THE PRESIDENT’S ADDRESS. 23

he further makes the important statement that the volume of

gas given off by these rocks, and which comes entirely from

the minute cavities within them,’ ranges from 1.3 to 17.8

times the bulk of the rock; that is to say, that a cubic mile

of stone would give out from one to seventeen cubic miles of

gas. Considering these figures the problem begins to assume

a new aspect and our next question is, How many of these

cubic miles of rock have we at command? Because it is

evident that if we only have miles enough we can get enough

carbon-dioxide.

At this point in the enquiry I was stopped for a while.

How is it possible to ascertain the amount that has been

worn off the surface of the crystalline rocks since geologic

time began? I laid the subject aside for a time. But soon

the thought occurred that the mass of the sedimentary rocks,

with a few corrections, must equal the amount worn off the

crystallines since the days when these latter composed the

whole surface. But it is not easy to obtain even this datum

and any result must be merely approximate.

I may here be allowed to digress for a moment to explain.

All geologists who accept the principle of cosmic evolution

(and in the present day few can be found who reject it) are

agreed that the earth has cooled and consolidated from an

early liquid mass, consisting of slaggy, glassy and stony

material, resembling modern lavas. From this hard and

intractable rock-mass all our sandstones, shales, clays and

limestones have been slowly separated by the disintegrating

and dissolving action of water. Over and over again have

these strata been broken up and swept away by rains and

rivers, until the ancient crystallines have gradually been

buried under their own ruins and now occupy comparatively

a small part of the surface. None the less has every particle

1. Asa proof of this fact Professor Tilden incidentally remarks: ‘‘The gas is appar-

ently wholly enclosed in cavities which are visible in thin sections of the rock when viewed

under the microscope; but as they are extremely minute, very little gas is lost when the rock

is reduced to a coarse powder, and as a result of experiment in one or two cases I find that

practically the same amount of gas is evolved on heating the rock, whether it is used in small

lumps or in powder.”

24 EDWARD W. CLAYPOLE :

of the sedimentary strata, except carbon and carbon-dioxide,

been derived from their steady destruction, the amount of

which must, of course, be approximately equal to the mass

built up from their ruins.

Had the geologist senses sufficiently exalted he might hear

the miniature explosions, as one after another, or, many at

the same instant, these little ‘‘sealed flasks” burst and dis-

charge their highly compressed contents. In grinding down

a thin slice, myriads of them are opened and their gases lost.

So in nature, as erosion thins down their crystal walls,

these ultimately become so weak that they can no longer

withstand the bursting pressure within and a microscopical

explosion ensues.

The area of the dry land of the globe equals about

60,000,000 square miles, and by far the greater part of it is

covered with thick sheets of sediment. Deduction must be

made for the areas where these are absent and the old

crystalline rocks still form the surface. But, on the other

hand, a large addition is due on account of the sea-margins

which for 200 or 300 miles from shore are covered with

the wash from the land. With the deep sea I will not here

deal.

I assume, then, that one of these corrections will counter-

vail the other and that the area of the sedimentary strata is

equal to that of the present dry land or 60,000,000 square

miles. Now the thickness of these rocks is very various,

ranging from ten miles down to nothing. The former figure

is seldom found, but it appears to me that to assume an aver-

age depth of one mile is not unreasonable. This will give us

for the whole mass eroded from the ancient crystalline rocks

the sum of 60,000,000 of cubic miles.

Regarding the quantity of carbon-dioxide contained by the

rocks on which Professor Tilden experimented, the following

figures are taken from the report of his paper given in the

Chemical News for April 9, 1897:

THE PRESIDENT’S ADDRESS. 25

In 100 vols.

Vols. CO nuh.

Granite, near Dublin, acid, Plutonic. . ... . 5.0 94 906

Granite, Ardshiel, acid, Plutonic ........ . 6.9 795 20.5

| Greisen, Altenburg, Sax., altered, Pitane strahec 1.8 136 864

Granulite, India, altered, Plutonic. ...... 2.6 A8-7 15753

3 | Quartz-Schist, Co. Down, Metamorphic .. . . 2.8 23.0 77.0

oe Fuchsite Schist, Baroda, Ind., Metamorphic. . 4.2 20.8 792

o Corundum Rock, Rewah, Ind., Metamorphic. . 35 26.0 74.0

Pyroxene Gneiss, Ceylon, Metamorphic... . . 73 84.4 15.6

| Gneiss with Corundum, Seringapatam, Metamor-

LNG brig tarot BmomC ne cetro NOG 3 Polos o8 Over 17.8 180 82.0

Gneiss with Garnet gad Graphite, Ceylon... . 4.5 11.0 89.0

GneisswmLiimalayasn ae cere erences kel ey ae HE: 15 «688.5

Pete) Galeiss: 2 ee eS df. Sat a) ESS se oe eS 5:3 823 13.6

wg | Felspar. 2 ee ee ; 1:3 OAS. 2 §2n2

= S ——

ae 13—70.2 13—522.9

5-4 40.

These results give us an average of five and a half volumes

of gas from every volume of rock, and of this quantity 40 per

cent. was carbon-dioxide. Combining the averages we find

that these Archean minerals yielded between two and three

times their volume of carbon-dioxide. Combining again with

the previous result—60,000,000 cubic miles of eroded crys-

talline rock—we obtain about 150,000,000 cubic miles of gas.

Of this the three-thousandth part will be carbon in the solid

form.

In this way the final result is reached; that by these

minute contributions we get about 50,000 cubic miles of car-

bon, equal to at least 60,000 cubic miles of coal. As the

total stock of existing coal amounts to only about 2,000 cubic

miles, or with all the other forms of unoxydised carbon, to

not more than 50,000 cubic miles, we have a supply ample

and more than ample for the demand.

In such an investigation I need not caution anyone against

laying much stress on the exact figures here given. A calcu-

lation when the data are so indefinite can but be approximate.

Yet I hope I have shown that allowing for all inaccuracy we

26 EDWARD W. CLAYPOLE :

have here a supply of the precious element, carbon, from

which the geologist can obtain his coal without offending his

brethren, the botanist and the geologist, by insisting upon a

greater amount at any time in the atmosphere than they are

willing to allow. Here we have a supply from which it can

be drawn as wanted without disturbing the existing balance

of atmospheric composition, or compelling us to assume that

in the early days of life the air was materially different from

what it is at the present time.

I am sure it must be interesting to the working members

of the American Microscopical Society to see how the inves-

tigation of these minute bubbles in the crystalline rocks leads

on to the discovery of a possible origin of the carbon in our

coal. To any geologists present I must excuse myself for

considering only one part of the problem and saying nothing

of the other stores of this carbonic acid in the rocks of the

earth compared with which the coal and other free carbon in

the earth is a mere vanishing quantity. But the conditions

differ and the solution of that problem must differ also.

The unconsidered elements would, if introduced, vastly

and unduly extend this discussion, while they would not in

any way conflict with what I have said. They would com-

plicate, but not invalidate the argument. I have merely

endeavored to put forward and maintain a mechanism whereby

carbon-dioxide could be obtained as wanted by the plant-world

without charging the atmosphere with the whole amount at

once.* I have shown how the deposit in the atmospheric bank

can be maintained through the receiving teller while the pay-

ing teller is constantly releasing it in response to checks on

demand.

Meanwhile I have given you a glimpse down some of the

long vistas of geologic time. I have brought before you

1. An interesting possibility—I may say, from some points of view, a probability—would

lead us too far here, if we were to attempt its discussion. But there is nothing unlikely in

the supposition that the whole oxygen of the atmosphere has been set free from its com-

bination in the form of carbon-dioxide by the action of plant-life. Such a supposition is

beset with some difficulties, not, perhaps, insuperable, but it has many strong reasons in its

favor.

THE PRESIDENT’S ADDRESS. 27

some of the processes of world making—some actual records

of zons long gone by—some relics of remote conditions

entombed when time was young. You have, in imagination,

seen the glowing lithosphere slowly cooling and crystallising

and as the solid earth was built there were stored in its foun-

dation stones these samples of its primeval atmosphere,

sealed in their crystal flasklets. The building advances, the

cooling nucleus contracts, the cold and solid crust outside,

being unsupported, sinks and is crushed. You hear, as it

were, the creaking of the massive globe as its crystalline

particles yield before the inconceivable earth-forcé. Then

—in that time, not of disaster and catastrophe, but of slow,

imperceptible evolution—were graven on stone those mystic

characters which the microscope has interpreted to you this

evening.

APPENDIX.

(a) Amount of coal in the earth:

This is based on an estimated area of the world’s coal field equal to 500-

000 square miles, with an average total thickness, including thick and thin

beds, of twenty feet.

The result gives a layer of coal over the globe one-twentieth of a foot

thick.

(6) Amount of carbon-dioxide and carbon in the atmosphere :

This equals by volume, 545; by weight, 745.

The other data are as follows :

IAT EH One elODENE fae) ol nish ok eis oe Bens) = ons. >) ois 200,000,000) Sqz 11

Wepenrotaaine i Of unifonmidensityi: = 7.) = 21-2. <<.) ose) oe Aa

Hy pometical desty Of carbon vapor". 2... . 2) 2s ot eae AES

S PEGiiGueLAWILyAOL COAliir Wage sk ese) 2 38.) S 02. Re TREES

Section sLAvilyior swatCt tO: alt, tS ce.) |=il> "<7, oS; .*: 2 ie ee POTS

Result as given in text.

MICRO-STRUCTURAL CHARACTERISTICS OF STEEL.

FRANCIS SCOTT RICE, STEELTonN, Pa.

In 1864, Dr. H. C. Sorby, that capable veteran in micros-

copy, of whom our worthy President spoke last evening,

published a paper through the Sheffield (England) Literary

and Philosophical Society, entitled, A New Method of Illus-

trating the Structure of Various Kinds of Steel by Nature

Printing, so far as known the first paper treating of the

micro-examination of steel. He occupied the field alone for

nearly twenty years; but others took up the work, more

especially in England, until, in 1891, Mr. J. E. Stead writes:

‘‘It is evidently time that this particular branch of research

should not be neglected, and that in our works, and all

metallurgical laboratories, the microscope should hold a

prominent if not a premier position.” American workers

have taken up the subject, and at the present time the

method is used in examination of castings ; important pieces,

such as car axles ; inspection of armor plate for our navy ;

and, finally, in the study of various commercial forms of

steel with a view of improving the product and methods of

working. Scientific interest in the study will perhaps prove

sufficient to attract more workers, but the commercial impor-

tance of the results will surely make the microscope a most

valued instrument to the metallurgist in the near future.

The following notes may be of interest as recording the

experience of some study. As regards the preparation of

specimens :

After trying many sizes of sections, the uniform size of

three-fourths of an inch in diameter has been adopted as

MICRO-STRUCTURAL CHARACTERISTICS OF STEEL. 29

being convenient to mount on ordinary slips; much smaller

sections are hard to grind to a plane surface, having a ten-

dency to round on the edge, while in larger surfaces the cen-

tral part of the section is hard to polish. If the sections are

to be submitted to heat treatment after cutting in the lathe,

the thickness should be at least three-sixteenths of an inch

in order to properly retain heat. After many trials of emery

and crocus papers and powders, jewelers’ rouge, wheels

speeded to over 3,000 revolutions per minute and charged

with various polishing and cutting compounds, it is thought

that the best sections are obtained by carefully grinding

off the surface to a plane by hand on an ordinary quick-

cutting oil stone, then on the finest Belgian oil hone,

and, finally, polishing on a piece of chamois tightly stretched

over a block of wood and charged with peroxide of tin.

The last operation must be accomplished with frequent refer-

ence to the microscope, and to reach perfect results the per-

oxide of tin must be levigated and the finest powder only be

used for finishing. The peroxide tends to stick to the ground

surface of the specimen at first, but may be rubbed off with

a damp cloth and the polishing continued with very light

pressure until the surface becomes more smooth. Since

scratches can never be confounded with structure, a perfect

polish is for appearances only. The great object is to get a

perfectly clean, sharply cut plane without any distortion or

crushing of the softest structure on the surface. Finally,

wash thoroughly with alcohol, followed by a little chloro-

form.

A polished section of steel examined under the micro-

scope’by oblique reflected light appears uniformly dark, the

polished surface reflecting all rays of light outside of the

objective. Seen by direct reflected light, all rays will be

reflected to the objective and the surface appears uniformly

light. To develop the structure it is, therefore, necessary

to etch the polished surface. One method is by use of dilute

nitric acid, which is very uncertain and hard to control. A

30 FRANCIS SCOTT RICE:

better method is to dip the specimen into concentrated nitric

acid of specific gravity of 1.40 or more and then place under

a water tap. The concentrated acid has no effect until

diluted by the running water, when it etches rapidly for the

short time until it is washed off by the water. This applica-

tion may be repeated a second time if necessary. The

surest and most delicate results, however, seem to be gained

by use of a saturated solution of iodine in alcohol, diluted

with an equal quantity of alcohol, both 95 per cent. pure.

While comparatively slow and sometimes requiring many

applications before the desired effect is obtained, it can be

controlled and gives uniform results. After each etching

wash carefully in 95 per cent. alcohol, dry quickly or oxida-

tion will begin at once; polish briskly on chamois and

examine under the objective. When satisfactory the section

may be mounted on an ordinary slip with Canada balsam, so

that it can be used in the common mechanical stage or stored

in regular cabinets. A thin coating of vaseline has been

found the best protection from oxidation when not under

observation, and can be quickly cleaned, when necessary,

with a cloth and alcohol. The details of the structure are

almost wholly lost if cover slips are used.

The examination of the specimens requires some sort of

vertical illuminator. In the Tilghman type, through the

reflection of a beam of light from a thin, clear glass disc

placed in the optical axis at an angle of forty-five degrees,

the reflected rays pass vertically to the back of the objective

which acts as its own condenser, and throws a brilliant point

of light on the surface. Again reflected back to and gath-

ered by the objective, the image rays mainly pass through

the clear disc to the eye. This illumination gives the best

results with lower powers, and the photo-micrographs

appended were taken with its help. The prism illuminator,

as constructed by Zeiss, is a most perfect appliance and most

satisfactory for higher powers, from 4.3 mm. focus up. It

shuts off one-half of the objective, but the light is ample and

MIGRO-STRUCTURAL CHARACTERISDICS OF STEEL. 31

the definition beautifully clear. The beam of light for either

kind is most conveniently secured from a bull’s-eye between

lamp and instrument, and for photography the illuminant

must be cut down by diaphragms to a round, even circle of

light, the smaller in size the better for definition.

The photographic camera used was made to order by a

handy cabinet worker and designed after the suggestions of

Dr. Van Heurck in his book The Microscope. It is a vertical

box of right size inside for 8x10 inch plates, arranged with

slides for plate holders at different heights from the eye-piece ;

is supported by four stout legs of sufficient height to allow the

microscope to slide under it, and rests on a solid base board.

Velvet-lined slides confine the microscope always to the same

position ; the front and top are hinged so that focusing can

be easily accomplished for plates at any height. A simple

shutter, working from the outside, controls the exposure. It

is perfectly rigid and solid, can be used with immersion objec-

tives, and is convenient to operate. My own is made of

cherry and is a solid and rather handsome piece of furniture,

with no suggestion of its use in its appearance; but an

equally good one can be made of pine lumber for about five

dollars. This experience is given as a hint to those who,

although wanting a photo-micrographic camera, feel that the

expense would be burdensome.

Disregarding any small impurities, all steel is composed of

two primary constituents, which are known as ferrite, or the

original iron, and carbon, through the presence of which iron

becomes steel. Ferrite may occur either segregated and free

or in combination, but carbon is always in combination with

the iron, forming a carbide with the formula Fe,C., which is

called cementite. Cementite recombines with the ferrite to

form pearlyte in all steels normally cooled ; but combines in

a different proportion to form a different structure, called

martensite, if the steel be heated to 800° C. or over; and if

the specimen be then suddenly cooled by plunging into cold

water or other fluid, this form may be instantly ‘‘ fixed” and

32 FRANCIS SCOTT RICE:

then be available for microscopic observation. Steels cooled

as in ordinary working by the surrounding air, will be termed

‘‘normal” as regards heat treatment ; those suddenly cooled

will be called ‘‘quenched” ; and those cooled so slowly that

the whole mass of metal is practically of one temperature

until completely cooled, are termed ‘‘annealed.” This

nomenclature of microscopic constituents and conditions of

heat treatment is universally accepted by metallurgists in

microscopic work.

Passing to the conditions under which any or several of

these constituents appear, and the characteristics of each as

regards etching, color, proportion and structure: Ferrite,

the larger constituent, will, of course, appear alone in iron,

as in Fig. 18. In soft normal steels it appears as crystals,

mostly octahedra, as in Fig. 6. As carbon is added it com-

bines with the cementite to form pearlyte, until with 0.80

per cent. of carbon the whole mass is pearlyte, as in Fig. 10,

and this is termed the ‘‘saturation point,” since in steels

with greater percentage of carbon the cementite appears

segregated, as in Fig. 13. Under etching ferrite is dis-

colored, as in Fig. 7, but by rubbing on chamois is left clear

and white, as in Fig. 1; and slightly deeper etching shows a

papillar appearance on some grains with highly iridescent

effects, asin Fig. 2. Ferrite is the softest of the four con-

stituents.

Cementite occurs only in combination with iron, as

pearlyte or martensite, until the carbon percentage is greater

than 0.80 per cent., then appearing as plainly outlined cell

wall, as in Fig. 13, and with about 1.30 per cent. of carbon

as segregated masses, but is always structureless. It is the

hardest of the constituents, remains brilliant after etching

and has a more metallic appearance than ferrite.

Pearlyte is strictly a condition only of the combination of

ferrite and cementite in normal and annealed steels, while the

condition of the same combination in quenched specimens is

termed martensite. The distinction, however, rests not only

MICRO-STRUCTURAL CHARACTERISTICS OF STEEL. 33

on the micro-structural differences, but also on wholly differ-

ent physical characteristics. Martensite is the condition

under which steel exhibits hardness, while pearlyte possesses

no such properties. Pearlyte is colored dark by etching and

forms from none to 100 per cent. of the mass as the carbon

percentage rises to 0 80 per cent. The micro-structure is

somewhat uncertain ; but in crucible steels and those more

thoroughly worked it appears plainly as a laminated structure,

resembling little contour maps and formed of alternate plates

of cementite and pearlyte, as in Fig. 12. The lamination

gives rise to beautiful iridescent effects like mother-of-pearl,

whence its name. Since this effect appears in specimens

etched only in the slightest degree, I am inclined to believe

that we have here to do with a diffraction grating, formed by

plates of greater or less thickness and of different reflective

power.

Martensite is a differing condition of the same constitu-

ents, as in pearlyte, caused by heating. In specimens prop-

erly heated and quenched its proportion of the mass increases

with the carbon percentage until it forms 100 per cent. with

0.20 per cent. carbon; this proportion of the mass remains

constant until about 1.00 per cent. of carbon is added, when

free or segregated cementite appears. Combining in these

different proportions it forms a material of corresponding

hardness, and with etching deepens in color proportional to

the amount of carbon from a slightly yellow to almost per-

fectly black color. It may be added that martensite is the

key to the whole tool steel industry, and an immense amount,

in fact, nearly all of the micro-structural work done has been

to approve or disapprove the various theories of the harden-

ing of steel; whoever solves the micro-structure of marten-

‘site will not only settle the theories, but place tool steel —

manufacture on a sure and scientific basis.

It is anticipated that micro-structural study of almost

every variety of steel product will be taken up in the imme-

-diate future. As mentioned, it is used in examination of

34 FRANCIS SCOTT RICE:

armor plate, doubtless by showing how thoroughly and to

what depth a carbon absorption from the outside has hardened

a milder plate. It is also hoped that it will prove a quick and

sure method, both for manufacturer and engineer, in the pro-

duction and inspection of structural steels, leading to a more

homogeneous and reliable product, and safely allowing the use

of steels of higher carbon and correspondingly greater tensile

strength ; decrease the weight of bridges and add to the safety

of property and human life. The study has proved a most

interesting and absorbing one, although prosecuted in the

intervals of a very busy life, and perhaps in no field of micro-

scopic research are there more important results promised

from a scientific standpoint ; and abundant remuneration will

also come to the successful investigator. The presentation

of these few very imperfect results to this Society is a great

pleasure, and it is hoped that interest in the subject may be

awakened both in individuals and the Society. All the

figures herewith shown are from permanent enameled bro-

mide prints of a series of negatives taken under the same

conditions as regards plate, exposure and so nearly as possi-

ble development. The magnification is x200 diameters, and

each view shows an actual area of 1-100 inch or 0 25 mm.

Pieces marked ‘‘same as” are actually cut from same bar and

supposed to be of identical chemical composition. Several

failures are shown also, as examples of what to expect from

imperfect manipulation.

Io.

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20.

MICRO-STRUCTURAL CHARACTERISTICS OF STEEL. 35

BIBLIOGRAPHY.

H.C. Sorby: Ona New Method of Illustrating the Structure of Various

Kinds of Steel by Nature Printing. Sheffield Literary and Philosophical

Society, February, 1864.

H. C. Sorby: On the Microscopical Structure of Meteorites and

Meteoric Iron. Proceedings of the Royal Society, Vol. XIII., p. 333,

and British Association Report, Part I., p. 139, 1865.

H. C. Sorby: On Microscopical Photographs of Various Kinds of Iron

and Steel. British Association Report, Part II, p. 189, 1864.

H.C. Sorby: On the Microscopical Structure of Iron and Steel. Dr.

Lionel Beale’s How to Work with the Microscope, 4th Ed., pp. 181-183,

1868.

A. Martens: Ueber die Mikroskopische Untersuchung des Eisens.

Zeits. des Ver. Deuts. Ing, Vol. XXI., pp. II, 205 and 481, January, May

and November, 1878 ; also Vol. XXIV., p. 397, August, 1880.

H C. Sorby: Lecture delivered in the Firth College, read October 20,

1882. The Engineer, Vol. LIV., p. 308, October 27, 1882.

A. Martens: Ueber die Mikroskopische Untersuchung des Eisens.

Verhandl. des Ver. zur Beférderung des Gewerbfleisses, Sitzungsberichte,

p- 233, 1882.

J. C. Bayles: Microscopic Analysis of the Structure of Iron and Steel.

Trans. of the American Institute of Mining Engineers, Vol. XL, p. 261,

1883.

O. Dolliak: Beitrége zur Mikroskopie der Metalle. Mittheil. iiber

Gegenstinde des Artillerie und Geniewesens, Heft 9. p. 467, 1883.

A. Martens: Erlauterungen einer in der kén. Bergakademie zu Berlin

befindlichen Sammlung von 120 Schliffen zur Darstellung des Mikro-

skopischen Gefiiges verschiedener Eisen und Stahlsorten. Berlin, 1884.

F. Osmond et J. Werth: Structure Cellulaire de l’Acier Fondu.

Comptes rendus de l’Academie des Sciences, Vol C., p 450, February 16,

1885.

F. Lynwood Garrison: The Microscopic Structure of Iron and Steel.

Trans. American Inst. of Mining Engineers, Vol. XIV., p. 64, 1885.

H. Wedding: The Properties of Malleable Iron, deduced from its

Microscopic Structure. Journal of Iron and Steel Institute, p. 87, 1885.

F. Osmond et J. Werth: Theorie Cellulaire des Proprietés de 1’Acier.

Ann. des Mines, 8th Series, Vol. VIII., p. 5, July to August, 1885.

F. Lynwood Garrison: The Microscopic Structure of Car Wheel Iron.

Trans. American Inst. of Mining Engineers, Vol. XIV., p. 913, 1886.

H.C Sorby: On the Application of Very High Powers to the Study of

the Microscopical Structure of Steel. Journal of Iron and Steel Insti-

tute, p. 140, 1886.

H. Wedding: Die Mikrostructur des Gebrannten Eisens. Stahl und

Eisen, Vol. VI., p. 633, October, 1886.

H. Wedding: Die Mikrostructur des Eisen. Stahl und Eisen, Vol. VII.,

p- 82, February, 1887.

F Lynwood Garrison: Microscopic Structure of Steel Rails. Trans.

American Inst. of Mining Engineers, Vol. XV., p. 761, February, 1887.

A. Martens: Ueber das Kleingefiige des schmiedbaren Eisens, beson-

ders Stahls. Stahl und Eisen, Vol. VII., p. 235, April, 1887.

21.

22.

23:

24.

PRAN CIS SCOTT RICE:

H.C. Sorby: The Microscopic Structure of Iron and Steel. Journal

of the Iron and Steel Institute, p. 255, 1887.

H. Schild: Die Neuesten Forschungen auf dem Gebiete der Mikro-

skopischen Untersuchung von Stahl und Eisen, Stahl und Eisen, Vol. _

VIII., p. 90, February, 1888.

H. Wedding: Zusammenhang zwischen der Chemischen Zusammen-

setzung und dem Kleingefiige einerseits und der Leitungsgiite des Tele-

graphendrahtes anderseits. Mittheil. aus den kén. technischen Ver-

suchsanstalten, Ergiozungsheft I., p. 6, 1888.

H. Wedding: Ueber Fortschritte in der Lichtabbildung des Klein-

gefiiges von Eisen und die Herstellung von Schliffen. Stahl und Eisen,

Vol. IX , April, 1889.

A. Martens: Ueber die Mikro kopische Untersuchung des Kleingefiiges

von Eisen. Stahl und Eisen, Vol. IX , p. 393, May, 1889.

F. Osmond: Le Fer et l’Acier. Lumiere Electrique, Vol. XXXV., p.

256, February 8, 1890.

H. Wedding: Das Kleingefiige des Eisens. Mikroskopische Original-

photographien mit Erlauterungen Berlin, 1891.

Sir F. A. Abel: Presidential Address. Journal of the Iron and Steel

Institute, No. I, p. 18, 1891.

F Osmond: Note on the Micro-structure of Steel. Journal of the Iron

and Steel Institute, No. I, p. 100, 1891.

H. Behrens: Sur la Structure Microscopique et sur la Trempe de

V’Acier et de la Fonte. Recueil des travaux chim. des Pays Bas, Vol. X.,

p- 261, 18ot.

H. Wedding: Das Gefiige der Schienenképfe. Stahl und Eisen, Vol.

XI., p. 879, November, 1891.

A. Martens: Die Mikrophotographische Ausriistung der kén. Mechan-

isch-Technischen Versuchsanstalten. Mittheil. aus den kin. Technischen

Versuchsanstalten, Heft 6, p. 278, 1891.

P. H. Dudley: Microscopic Structure of Steel. Journal of the New

York Microscopical Society, October, 1891.

A Martens: Ueber Einige in der Mechanish-Technischen Versuchs-

anstalt ausgefiihrte Mikroskopische Eisenuntersuchungen. Mittheil. aus

den kén. Technischen Versuchsanstalten, Vol. X., p. 57, 1892.

A. Martens: Die Mikroskopische Untersuchung der Metalle. Glaser’s

Annalen, Vol. XXX., p. 201, 1892.

H. Behrens: Revue Générale des Sciences Pures et Appliquées. Vol.

IIl., p. 343, May 15, 1892.

A. Martens: Das Gefiige der Schienenképfe. Stahl und Eisen, Vol.

XII., p. 406, May 1, 1892.

H. Wedding: Das Gefiige der Schienenképfe. Stahl und Eisen, Vol.

XII., p. 478, May 15, 1892.

A. Martens: Das Gefiige der Schienenképfe. Stahl und Eisen, Vol.

XII., p. 530, June 1, 1892.

G Guillemin: Analyse Micrographique des Alliages. Comptes rendus

de l’Academie des Sciences, Vol. CXV., p. 232, July 25, 1892.

Tetskichi Mukai: Studien iiber Chemisch-Analytische und Mikroskop-

ische Untersuchung des Manganstahls. Freiberg, 1892.

F. Osmond: Microscopic Metallography. Trans. of the American

Institute of Mining Engineers, Vol. XXII., 1894.

A. Martens: The Micro-structure of Ingot Iron in Cast Ingots. Trans.

of the American Institute of Mining Engineers, Vol. XXII., 1894.

44.

45.

46.

47.

48.

49.

50.

MIERO-STRUCTURAE CHARACTERISTICS (OF STEEL. 37

A. Sauveur: Micro-structure of Steel. Trans. of the American Institute

of Mining Engineers, Vol. XXII, 1894.

H. Behrens: Das Mikroskopische Gefiige der Metalle und Legierungen.

Hamburg, 1894.

F. Osmond: Méthode générale pour l’Analyse Micrographique des

Aciers au Carbone. Société d’Encouragement pour |’Industrie Nationale,

Paris, May, 1895.

H. M. Howe: The Hardening of Steel. Journal of the Iron and Steel

Institute, No. 2, 1895.

H. H. Howe and Albert Sauveur: Further Notes on the Hardening of

Steel. Journal of the Iron and Steel Institute, No. 1, 1896.

Albert Sauveur: The Micro-structure of Steel andthe Current Theories

of Hardening. Trans. of the American Institute of Mining Engineers,

September, F896.

Thomas Andrews: Microscopic Internal Flaws, Inducing Fracture in

Steel. Octavo, pp. 52. London: E.& F. Spon. 1896.

The above list is believed to be exhaustive up to 1895, but is incomplete

from that time to date.

38 MICRO-STRUCTURAL CHARACTERISTICS OF STEEL.

PLATE I.

Fig. 1. Open hearth steel, normal, carbon 0.08 per cent. Attention is

called to the double cell walls plainly shown, which seem to indicate that each

cell has its own individual envelope ; observed for the first time, so far as

known. Ferrite is white ; pearlyte is dark portion.

Fig. 2. Same as Fig. 1, quenched. Crystalline ferrite, covered with iri-

descent papillz.

Fig. 3. Same as Fig. I, annealed.

Fig. 4. Open hearth steel, normal, carbon 0.30 per cent. Theoretically

should be ferrite 63 per cent. (light), pearlyte 37 per cent. (dark). The nega-

tives are not retouched, as the polishing scratches shown will bear witness.

Fig. 5. Same as Fig. 4, supposed to be quenched, but evidently not heated

enough or quenched with sufficient suddenness, since the whole mass should

appear as martensite.

Fig. 6. Same as Fig. 4, annealed. Ferrite (light) and pearlyte (dark)

crystals apparently with ferrite cell walls.

PLATE lI.

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40 MICRO-STRUCTURAL CHARACTERISTICS OF STEEL.

PLATE Il.

Fig. 7. Open hearth steel, normal, carbon 0.55 percent. Theoretically

should show ferrite 30 per cent., pearlyte 70 per cent, The darkest part, as

shown, is the ferrite after etching, but without polishing on chamois, after

which it would appear white. The pearlyte shows lamellar structure in

lighter portions.

Fig. 8. Same as Fig. 7, quenched. Whole mass of martensite.

Fig. 9. Same as Fig. 7, annealed. Crystalline structure, but is thought

that the specimen cooled too rapidly to allow full crystallisation to be accom-

plished.

Fig. to. Crucible steel, normal, carbon 0.90 per cent. Whole mass of

lamellar pearlyte. A very fine specimen of pure high grade carefully worked

steel. Ingot was hammered before rolling.

Fig. rr. Same as Fig. 10, quenched. Whole mass of martensite, but

apparently of finer grain than Fig. 8.

Fig. 12. Crucible steel, normal, carbon 0.97 per cent. Whole mass of

pearlyte, with small points of segregated cementite. Lamelle distinctly

shown.

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42 MICRO-STRUCTURAL CHARACTERISTICS OF STEEL.

PLATE Iil.

Fig. 13. Open hearth steel, normal, carbon 1.00 per cent. Meshes of net

pearlyte, outlined with free cementite walls.

Fig. 14. Same as Fig. 13, quenched. Martensite, the free cementite walls

of Fig. 13 being partially absorbed by the martensite.

Fig. 15. Open hearth steel, normal; carbon not known, but about 0.15 per

cent. A section of rivet after the specifications of a leading railway and,

therefore, a typical example of the best class of mild structural steel.

Fig. 16. Longitudinal diagonal section of iron wire from the main cables

of old Niagara suspension railway bridge. No carbon present and dark spots

are streaks of so-called “cinder.” After forty years use this wire shows an

average of 95,000 pounds tensile strength per square inch. Manufactured in

England.

Fig.17. Cross section of same as Fig. 16.

Fig 18. Longitudinal section of same as Fig. 16.

THE ROTIFERA OF SANDUSKY BAY.

‘SECOND PAPER.)

Bees? KELLICOEL, Pu. D., F. R. M.S., Co_umsus, O.

The paper offered last year, Pittsburg meeting,’ on The

Rotifera of Sandusky Bay, was a list, with notes, of sixty-

seven identified species. The present paper adds to that

list the species since studied and extends it to 106 species, of

which four are supposed to be new to science. Among the

forms hitherto known are several rare and striking ones, some

of which have not been before recorded as occurring in this

country. Several have but recently been discovered in

Europe, while one was described in 1893 from China, thus

adding one more antipodal species. The additional facts

here presented will, I think, prove interesting to students of

distribution of these charming animals.

A casual glance at the 106 names in this local list will at

once show that a majority of them are among the striking

forms; the more obscure ones have not been wholly neg-

lected ; and a few have been determined, but the sure iden-

tification of many others must be tested by further examina-

tion. It appears to the writer that many of these less

conspicuous species are not as yet described.

The chief method used in collecting was by means of the

‘‘tow-net,” hauled at the surface and at stated depths,

mainly at or near the surface. By hauling over the same

course day after day, at stated times, and under the extremes

of summer temperature, the successions and variations noted

in the rotiferal fauna have proven interesting, and under the

1. Proceedings American Microscopical Society, Vol. XVIII., page 155.

A4 D:\S.:-KELLICORE:

species name remarks are introduced on the time, place and

condition of capture. It is anticipated that after another

summer's observations are recorded the facts deduced will be

sufficiently important to warrant publication.

The nets used were made of silk-bolting cloth of the best

quality, having about sixty meshes in a centimeter. The

tow-net was made of the same diameter as the ordinary

plankton net, twenty-five centimeters. The gatherings by

this net were immediately passed to coarser and finer nets,

in order to remove small insects and the larger entomostraca,

as these active creatures soon exhaust the oxygen and over-

come the more delicate Rotifera. The ‘‘sorted” material

was then put in rather large bottles separately and fragments

of aquatic plants introduced. The wheel-animalcules were

found to remain alive under these conditions a sufficient

length of time. When brought to the table for study the

Rotifera were again concentrated by passing the large quantity

of water from the bottles through sieves of the finest silk ;

the pipette would then remove the last few drops from the

apex of the conical sieve to the slide or compressorium highly

charged with the forms desired.

For narcotising these animals hydrochlorate of cocaine,

I.5 per cent. strong, was employed with very satisfactory

results. Quieted in this way they are in excellent condition

for study, or may then be fixed and stained in good condi-

tion."

68. Floscularia edentata, Collins. :

Under leaves of water-lily in a small pond between the

parallel dunes at Cedar Point. It was not uncommon in this

pond, but not found elsewhere.

APSILUS, Metschnikoff.

69. A. bipera, Foulke.

Few taken in tow-net at the surface among aquatics in the

1. See paper by Rousselet, Quek. Mic. Club, Vol. V., page 205.

THE ROTIFERA OF SANDUSKY BAY. 45

cove near pumping station. I follow Dr. Stokes in separat-

ing dzpera from its congeners.!

One was taken with a young within in which the two

large red eyes were conspicuous.

STEPHANOCEROS, Ehrenberg.

70. S. Eichhorniz, Ehrenberg.

Comparatively rare. It occurred on dissected leaves of

aquatics in quiet, clear water.

71. Melicerta ringens, Schrank.

Few seen ; all on Utricularia from ‘‘ Black Channel.”

72. WM. tubtcularta, Ehrenberg.

This beautiful creature was common on U¢ricularia

shallows on Cedar Point. 7. floccosa, described in the first

paper, is clearly distinct.

73. Ccistes umbella, Hudson.

Not uncommon with the last.

74. Conchilus unicornis, Rousselet.?

Exceedingly abundant in surface tows in all parts of the

bay, more especially over clear, shallow areas.

75. C. dossuartus, Hudson.

Only in surface tows in Biemiller’s Cove, Cedar

Rare.

The separated part of the antenna is much longer

Point.

than Dr. Hudson’s figure indicates.

MIKROCODIDES, Bergendal.

76. M. dubius, Bergendal.3

Not uncommon in a permanent pond in the sand, sur-

rounded by high dunes at Cedar Point.

ASPLANCHNA, Gosse.

77. A. priodonta, Gosse.

Very common in surface tows in all parts of the bay.

1. See Journal R. M. S., Vol. XVI., page 269.

Journal Quek. Mic. Club, Vol. 1V., page 367.

3. Rotatorienfauna Groenlands, page 34

46 D:iSipKEBLLICOLT!:

78. Sacculus orbicularis, n. s., Fig. 1.

Length of retracted animal, .124 mm. ; width of lorica

from the side, .114 mm.

From the side the outline is circular, with a neck-like pro-

jection anteriorly ; the width of the neck about one-third as

wide as the body, its edge is coarsely crenated, the rounded

processes being alternately larger and smaller. From above

the outline is oblong, its transverse diameter about one-half

that of the vertical height. The lorica is thick and firm,

resembling in this regard that of Azapus ovalis, but no divi-

sion into plates could he made out.

IDE, Ue

The corona has the cilia in tufts, and from near the dorsal

surface arises a long, straight antennal process; the rather

small mastax is furnished with very slender trophi ; the large

stomach and conspicuous ovary occupy nearly the whole space

of the lorica. The whole animal has a slightly reddish hue.

Very many were taken in the tow-net in Biemiller’s Cove

during July. Very few were seen alive, as they are not at

all hardy and would be found, with careful treatment, inac-

tive or dead when carried from the place of capture to the

microscope, a mile away. It is an interesting form and one

that should have more thorough study than I have been able

to give to it as yet. It appears to differ sufficiently from all

described forms and is placed in the genus Saccul/us, with

grave doubts as to its affinities.

THE ROTIFERA OF SANDUSKY BAY. 47

79. Syncheta pectinata, Ehrenberg.

Constant and plentiful in hauls at the surface of clear water.

80. S. stylata, Wierzejski.

With the last and usually more abundant.

81. Plesoma truncata, Levander.?

Few seen in surface tows about Cedar Point, June 24th.

Sketches were made before it was discovered to be truncata ;

the identification was satisfactory in every particular. Taken

with P. lenticulare and the next.

o2, P: mollis; ns;

=eneth of lorica, .24 nim. ; of foot fo “end® of stees

.14 mm.

The body is oblong, in side view trumpet-shaped as it

widens toward the corona, which is relatively very deep.

The lorica is very thin and flexible ; it is coarsely areotate,

the round depressions are between ridges which longitudin-

ally follow the curves of the valves; there are three faint

transverse elevations in the middle of the dorsum ; the neck-

shield is narrow with anterior margin obtuse. The posterior

end of the body may be protruded until the part is very

nearly pointed or drawn in until quite obtusely rounded.

The stout foot ends in long, pointed toes; it issues

between the lateral plates of the lorica near the middle

of the venter, and extends a little farther back than the

extended body. The very broad corona has a powerful

wreath and tufts of cilia; there is a stout antenna on either

side and several (probably six) large decurved sete between

them. Situated ventral of these are others (probably

the same number), smaller and decurved. The delicacy

of the lorica renders the internal structure quite visible ;

the anterior part is transparent, in which the large three-

lobed brain, with a prominent eye situated on the anterior

part of the middle lobe, is seen, and below the oblong

1. Akademie d. Wiss. in Krakau, 1892.

2. Acta Societatis pro Fauna et Flora Fennica, Vol. XII., page 25.

48 D.S. KELLICOT? *

mastax with the powerful trophi ; the posterior part is occu-

pied by the less transparent alimentary canal and ovary.

It occurred sparingly towards the end of July, taken only

in surface hauls in clear water over weeds. It is a powerful

swimmer and on the slide goes tearing about in a resistless

way among the weaker forms. I have followed Jennings in

placing Ple@soma in Hydatinidz, not feeling satisfied, how-

ever, with the arrangement.

Norops, Hudson.

83. MV. minor, Rousselet.?

Very abundant in surface tows in clear water at Cedar

Point. It is a very pretty species, resembling in outline and

actions a species of Sacculus ; the anterior border of the

thick cuticle is crenate.

84. Motommata vorax, Stokes.?

The animal agrees well in size, form and surface, with Dr.

Stokes’ description. It occurred in tows among the weeds in

all parts of the bay.

85. Copens Ehrenbergiz, Gosse.

Few among Utricularia gibba from a pond at Cedar

Point.

86. Proales algicola, n. s.

The body, when swimming or when pushing through the

mucilaginous matrix of Azadbena, in which it lives, is nearly

cylindrical, slightly truncated posteriorly and somewhat

broader anteriorly. When quietly feeding the ventral line is

straight or slightly arched and the dorsal is strongly arched,

the body being thickest behind the middle. Seen from

above the outline, when quiet, is oval, narrower in front, the

‘‘head” separated by a constriction ; the head part is some-

what conical, and a short distance back of the position of the

eye there is a transverse ridge ; there is a longitudinal fold

1, Jour Quek. Mic. Club, Vol. IV., page 359.

2. Ann. and Magazine of Nat. Hist., S. 6, Vol. XIX., page 628.

THE-ROTIFERA. OF: SANDUSKY BAY. 49

on each side of the back. The face is slightly oblique, the

mastax ovate, the trophi strong, virgate, and when the ani-

mal is feeding approach closely, but do not quite reach the

front. The eye is large, red, and in two parts, separated by

a space equal to the diameter of the parts; it is on the front

of the brain on a level with the apex of the jaws. The foot

and toes are minute ; the latter are pointed and barely reach

the end of the body when turned back.

The body is hyaline, except as obscured by the rich yellow-

brown of the large stomachand intestine. Olderexamplesare

tinged with this color throughout ; the very young are color-

less, but soon take color after they begin to feed on the alga.

Anabena gelatinosa, Wood, often occurs in such vast

quantities in the harbor that the waterisdeepyreen. In the

gelatinous masses the rotiferon resides, feeding and deposit-

ing its eggs in a way similar to Hertwigta parasita in Volvox

globator. It was not unusual to find several adults, young,

and eggs ina single frond. The eggs are relatively large.

When the alga is broken up the rotiferon swims freely and

rapidly in search of another suitable home. This species

was found in one other habitat. On the Peninsula at Marble-

head there are very deep and wonderfully complex glacial

grooves in the limestone. In one of these, known as the

‘‘bath-tub,” I found the water turbid with a small, green,

unicellular alga; in this menstruum were a few of this

rotiferon having the characteristic color. The species

appears to be near P. otodon, but is sufficiently distinct.

EOSOPHORA, Ehrenberg.

87. £. aurita, Ehrenberg.

Very abundant from strainings from cove near pumping

station.

DIGLENA, Ehrenberg.

88. D. forcipata, Ehrenberg.

' With the last ; not very common.

50 Ds! KELEICOLRE:

HERTWIGIA, Plate.

890. H. parasita, Ehrenberg.

Not uncommon in Volvox globator, which occurs through-

out the marshy portions of the bay. This interesting little

rotiferon was found, April 3, 1897, in great numbers in a

small artificial pond of two years’ standing, fed by spring

water, in Minerva Park, Columbus, O. The host was so

numerous that it gave a green color to the water. To

determine the extent of the invasion I counted five lots of

100 each and found in the 500, 188 that were occupied. As

some of these had more than one guest, and often from two

to five eggs, there were about as many parasites, counting

eggs, as hosts. Mr. Gosse remarks in The Rotifera, Vol. II.,

page 39, that ‘‘the Vo/vox appears to suffer little from the

depredations of its ungrateful guest.” This can hardly be

true, forin colonies of this collection that had many occupants

the surface zodids were more or less destroyed, the clusters

gone or mangled; the whole colony looked sickly and dis-

couraged. Ten days after the first visit I returned to the

same pond and could only find an occasional Vo/vox and not

an occasional Proales. Where were hosts and guests?

90. Mastigocerca rattus, Ehrenberg.

This elegant species was taken a few times in tows made

in clear water over weeds.

gt. WM. bicristata, Gosse.

Not uncommon near shore. Our rotiferon does not agree

well with Mr. Gosse’s figure, as the carine do not extend so

far back and the outline shows a stouter form.

92. IM. elongata, Gosse.

Few in cove at pumping station. A most beautiful species.

93. M. multicrinis, n. s. _Figs2 and*3.

Length, .184 mm.; greatest width, .120 mm. ; length of

coe, ~ LOO {mm

THE ROPTIFERA- OF SANDUSKY BAY. SI

Lorica from above ovate, nearly symmetrical, anteriorly

constricted to a cylindrical neck. There are a few faint

carine dividing the surface into coarse facets ; there are also

faint longitudinal lines, somewhat irregular in direction, giv-

ing the surface the appearance of watered silk. These mark-

ings are seen only under favorable illumination. The anterior

dorsal edge of the lorica has a stout tooth and two crena-

Fie. 2. EiG:; 33

tions each side ; the same border below has centrally a large

round process and each side of this two similar and smaller

ones. The posterior end is obtuse with a constricted part.

In profile the dorsal outline is convex, the lower border con-

vex, but on a shorter curve from base of the ‘‘neck” to the

foot. The toe is long and straight, with three spines at the

base: one short, stout, curved over the toe, then turned

back; the others are minute scales.

The large red eye is apparently upon the brain ; the mas-

tax is oblong and the trophi powerful, of the usual type. In

some examples the anterior of the body is hyaline and as

52 De 'se KECEICORT:

glass-like as in Asplanchna ; in others the large ovary and

large brown stomach occupy nearly the whole body space.

In the transparent ones the retractor muscles of the corona

and the cesophagus are readily traced. The corona has a

peculiar supply of antennal appendages: in the middle of the

upper border there is a long, straight process, with obtuse

apex; below this is a short and more pointed process and

either side a pair of long, slender appendages, the upper and

inner one of each pair is somewhat curved towards the mid-

dle and the apex is nearly acute; the other one is slightly

enlarged apically. These are equal in length and slightly

shorter than the first.

The cilia are powerful, arise from large processes placed

laterally ; a lunate one above, conical ones below.

The species is a strong swimmer and occurs sparingly in

coves, taken at the surface. It should be compared with JZ.

lata, Jennings, from Lake St. Clair. It certainly resembles:

that species, and if the describer of /ata had not given such

an exact and detailed description they might easily have

been confused. The present species is broader and the toe

shorter, the toe spines quite different, the lorica is more

nearly symmetrical, with its anterior border totally different

and also the coronal appendages.

Compared to other species of Mastigocerca, multicrints

and /ata appear to belong elsewhere. They are the only

ones with their peculiar type of lorica and with such com-

plex coronal appendages.

DINOCHARIS, Ehrenberg.

94. D. poctllum, Ehrenberg.

Abundant from near the bottom in shallows.

POLYCH A1US,- Berty:

95. WP. subguadratus, Perty.

Rare. Taken in tow-net among aquatics.

THE ROTIFERA OF SANDUSKY BAY. 53

96. FP. serica, Thorpe.*

Very numerous in tows among vegetation in clear water

at Cedar Point ; also in ponds in the sand.

97. Stephanops muticus, Ehrenberg.

Not common. Besides the usual or normal form there

are those that are broad and exactly of the outline of S.

Groenlandicus, Bergandal, except it has the neck of mutzcus.

This variety needs further study and comparison.

98. Cathypna leontina, Turner.?

Abundant in a pond on Cedar Point and in Black Channel.

Rare elsewhere. This appears to be C. scutarza, Stokes.

99. Distyla spinigera, Western.?

Not common ; only taken in pond on Cedar Point. This

perfectly distinct species is a handsome addition to our

rotatorial fauna.

NOTAGONIA, Perty.

100. WV. Ekrenbergit, Perty.

This unique form was often found among plants from

Cedar Point. I can see no reason for separating it from

Metopidia as the angles of the lorica are, as it seems to me,

simply specific and as the paired organ, described as project-

ing from the head, appears to be only the usual hood.

101. Brachtonus angularis, Gosse.

Exceedingly abundant in surface hauls in cove at pump-

ing station. I at first took it for B. mollis, Hemple.

102. JB. pala, Ehrenberg.

Not common, with the last. Both the normal form and

the variety without the lateral posterior spines occurred.

103. JB. tuberculatus, Turner.+

Rather more common than fa/a in the same locality. A

I. Journal R. Mic. Soc., Vol. XIII., page 152.

2. Bull. Scientific Labs. of Denison University, Voi. VI., page 6r.

3. Jour. Quek. Mic. Club, Vol. V., page 427.

4. Bull. Scientific Labs. of Denison University, Vol. VI., page 65.

54 THE ROTIFERA OF SANDUSKY BAY.

fine species. I cannot agree with the distinguished authority

who places this as a variety of B. dakertz. Mr. C. C. Mellor,

of Pittsburg, found this form in the canal at Newark, O.,

August 24, 1888, and later sent me an accurate sketch which

I have still.

104. Anure@a tecta, Gosse.

Few only of this distinct species seen, taken in tows at

Black Channel.

NOTHOLCA, Gosse.

105. JV. longispina, Kellicott.

Few in strainings from water-supply and occasionally one

from Cedar Point. It is common at times in Lake Erie and

one might expect to find it more commonly in so large a

bay, open so freely to the main body.

FAMILY XX. PEDALIONIDA.

PEDALION, Hudson.

106. P. mirum, Hudson.

A few were taken in nearly every haul made in clear

weather near Pumping-station Cove.

This is one of the finest additions to our fauna.

Remarks on certain species of the first list :

Floscularia Millsit was abundant last year, but could not

be found in any part of the bay after much search. Mr. Jas.

B. Shearer, of Bay City, Mich., found it plentifully at his

station in June, 1895.

Melicerta floccosa has not been found again. This L

regret, for there should be further study of it and a figure.

Stephanops chlena has not again appeared. It has been

suggested to me by a gentleman thoroughly conversant with

these animals, that I may have had in hand Mzkrocodides

dubins. I certainly have the latter species now and still

expect to find chlena.

NOTICES OF SOME UNDESCRIBED INFUSORIA, FROM

THE INFUSORIAL FAUNA OF LOUISIANA.

J. C. SMITH, New OrtveEans, La.

FAMILY PARAMONADID&, Kent.

GENUS PETALGMONAS, Stien.

Petalomonas involutus. Sp. n. Plate I., Fig. 1.

Body discoidal with the lateral borders equally involute,

both extremities rounded, very much flattened, less than one

and a half times as long as wide ; flagellum as long as the

body and vibratile at its distal end only ; oral aperture indis-

tinct ; contractile vesicle conspicuous and in the anterior

body-third to the left of the median line ; nucleus round and

sub-central; endoplasm exceedingly transparent and the

posterior half usually coarsely granular; movements slow

and even; reproduction by longitudinal fission.

Length, 1-1833-inch; habitat, pond water.

FAMILY ASTASIAD, Kent.

GENUS ASTASIA, Ehrenberg.

Astasia invaginata. Sp.n. Plate l., Figs. 2, 3 and 4.

Body elongate, cylindrical, highly metabolic, from ten to

fifteen times longer than wide, both extremities attenuate,

the posterior roundly pointed, the anterior sharply pointed

and giving origin to a heavy cord-like flagellum, which is

exceedingly active and equaling in length three-fourths of

the body length ; oral aperture apical, no distinct pharyngeal

56 }e2Go SMILES

passage ; contractile vesicle small and located a short dis-

tance behind the apex; nucleus obscure ; endoplasm trans-

parent and containing a large number of bluish-colored cor-

puscles, which keep moving incessantly from one extremity

to the other in unison with the peristaltic movements of the

body; movements natatory and repent.

Length, 1-275-inch; habitat, ditch water.

The corpuscles contained in the endoplasm and their

movements, as well as the peristaltic and repent movements

of the body, impart to this infusorian a striking resemblance

to the Distigma proteus, Ehrenberg. The sharply pointed

anterior extremity, the cord-like flagellum and its origin,

have their counterparts in that peculiar flagellate infusorian

which inhabits the intestine of our common house-fly, the

Hlerpetomonas muscé-domestice, Burnett.

There is a peculiarity exhibited by this form, which, so far

as the writer is acquainted, is unlike anything shown by any

other infusorian ; that is the invagination of the anterior por-

tion of its body. During its repent phase the body becomes

much contorted and inflated anteriorly, and when these con-

tortions cease (lasting only a short while), the anterior of the

body is invaginated and presents a cup-like appearance, with

the apex extending vertically from the bottom and the flagel-

lum actively lashing about ; from the posterior of this cup-

like arrangement, all that portion of the body not included

in this invagination, extends as a pedicle, and becomes

attached to the slide or to adjacent débris; this cup-like

portion then remains comparatively quiet, while the flagellum

is moved about very actively, or it may sway to and fro, or

it may revolve; when this last-mentioned antic is in opera-

tion, the infusorian invariably breaks loose from its attach-

ment and is carried about for a short while in an eccentric

manner by the activity of the flagellum, when it again resumes

its natatory form.

It seems to have a fondness for debris heaps, as it will

remain partially obscured in one of these heaps for a long

NOTICES OF SOME UNDESCRIBED INFUSORIA. 57

time and thus call into play the patience of the observer. It

also seems to be rare, the writer not having seen it more

than six times in the last four years.

FAMILY ANISONEMIDZ, Kent.

GENUS HETERONEMA, Dujardin.

FHeteronema lunarts. Sp. n. Plate I., Fig. 5.

Body sublunate, compressed, highly metabolic, twice as

long as widest part, both extremities sharply pointed, dex-

tral border convex, sinistral border concave and ventricose

centrally ; flagella originating at the anterior extremity, the

anterior one equaling near one and a half body lengths, while

the trailing one equals one body length ; oral aperture apical,

followed by a distinct pharynx, which continues backwards,

medianly, through about one-fourth of the body-length and

there meets a round and conspicuous contractile vesicle ;

nucleus ovate and located obliquely in the posterior body-

fourth ; endoplasm transparent and usually containing fairly

large granules of food ; movements slow and equable.

Length, 1-700-inch ; habitat, pond water.

FAMILY PARAMACIID#, Kent.

GENUS LOXOCEPHALUS, Eberhard.

Loxocephalus luctdus. Sp.n. Plate IL, Fig. 6.

Body subelliptical, cylindrical, persistent in shape, less

than three times as long as wide, posterior rounded, anterior

slightly truncate obliquely and flexed towards the ventral

surface ; oral aperture round, located in the concavity pro-

duced by the anterior flexure, and continued obliquely down-

wards for a short distance in a distinct pharyngeal passage ;

oral cilia fine and very active ; body clothed with fairly long

cilia, which are stiff and inactive while the infusorian is feed-

ing ; no adcurved sete as in Loxocephalus granulosus, Kent.

A single long hair-like seta projecting from the posterior

58 JeC.“SMITEH:

border ; contractile vesicle round, conspicuous, and located

in the center of, and almost in contact with the ventral sur-

face ; nucleus roundish and subcentral; anal aperture in the

posterior fourth of the ventral surface ; endoplasm more or

less filled with large granules of a dark color; reproduction

by transverse fission ; conjugation by the application of the

oral apertures ; movements rotary.

Length, 1-500- to I1-275-inch; habitat, pond water.

In shape and endoplasmic contents this form resembles

very much the Loxocephalus granulosus of Kent. The dis-

tinct oral aperture and pharynx, as well as the position of

the contractile vesicle and general average larger size, will

serve to identify this new form. From the Dexiotricha plagia

of Stokes, it can be recognised by the absence of the setose

adoral cilia and trichocysts.

In its habits it is not unlike the Loxocephalus granulosus.

The very apparent oral aperture and pharynx as distin-

guished from the obscure oral aperture of the Loxocephalus

granulosus, has suggested its specific name.

FAMILY PRORODONTID#&, Kent.

GENUS NASSULA, Ehrenberg.

Nassula magna. Sp. n. Plate I., Fig. 7.

Body obovate, cylindrical, soft and flexible, less than

twice as long as wide, and finely ciliated ; pharyngeal rod—

fascicle forming an even, undilated tube, located in the cen-

ter of the anterior body- half; contractile vesicle large, round

and situated in the center of the posterior body-half on a

line with the oral aperture; nucleus round and subcentral ;

trichocysts very abundant and conspicuous ; color yellowish-

brown; movements rotary; reproduction by transverse

fission.

Length, I-150- to I-120-inch; habitat, pond water with

alge.

NOTICES OF SOME UNDESCRIBED INFUSORIA. 59

FAMILY PRORODONTIDA, Kent.

GENUS HOLOPHRYA, Ehrenberg.

Holophrya curvilata. Sp. n. Plate I., Fig. 8.

Body ovate, cylindrical, soft and changeable in shape, less

than twice as long as wide, posterior rounded, anterior trans-

versely truncated and including the simple oral aperture ;

body clothed in longitudinal rows, with fine vibratile cilia ;

body and oral cilia not diverse ; contractile vesicle large,

round and postero-terminal ; nucleus ribbon-shaped, convo-

lute and subcentral; endoplasm yellowish and granular ;

movements rotary ; reproduction by transverse fission.

‘Length, 1-160-inch; habitat, ditch water with alge.

FAMILY TRACHELOPHYLLIDA, Kent.

GENUS UROTRICHA, Clap. and Lach.

Urotricha hyalina. Sp.n. Plate I., Fig. 9.

Body oblong, cylindrical, from two to two and a half times

longer than wide, elastic and persistent in shape, posterior

border rounded, anterior border transversely truncate and

including oral aperture ; body covered with fairly long and

active cilia ; cuticular surface smooth ; a single long hair-like

seta projecting from the posterior border ; contractile vesicle

conspicuous and located in the posterior body-fourth ; nucleus

round and in posterior body-half ; endoplasm very transparent

and always containing large food balls of a bluish-green

color; anal aperture at the posterior border; reproduction

by transverse fission ; movements rotary.

Length, 1-750- to I-450-inch; habitat, pond water.

This form is quite abundant at times and always contains

the above-mentioned bluish-green balls, which resemble

somewhat the endochrome of the Oscz//aria. The writer has

attempted a number of times to determine whether or not

this infusorian feeds specially on this class of alge, but with-

out satisfactory results. The hair-like caudal seta is unlike

60 Ji CASMITH s

that possessed by the Urotricha lagenula of Ehrenberg, and

the Urotricha platystoma of Stokes, as it does not seem to

possess the power of springing the infusorian as is recorded

of the caudal setz of the two forms mentioned.

FAMILY ENCHELYID&, Kent.

GENUS TILLINA, Gruber.

Tillina disstmilis. Sp. nz»: Plate 14 Hig: 10:

Body ovate, subcylindrical, elastic and persistent in shape,

twice as long as wide, the anterior half of the ventral sur-

face much compressed and usually corrugate ; body clothed

with fine vibratile cilia and longitudinally striate ; oral aper-

ture located in the center of the ventral surface and continued

. as a distinctly ciliated pharynx, which is curved strongly in

the direction of the anterior extremity ; contractile vesicle

immediately behind the oral aperture and developing four

small vacuoles at each contraction; nucleus not observed ;

endoplasm transparent and granular ; reproduction by trans-

verse fission.

Length, 1-375-inch; habitat, hay infusion.

The anterior flexure of the pharynx and the behavior of

the contractile vesicle individualises this form.

FAMILY OPHRYOGLENID&, Kent.

GENUS OPHRYOGLENA, Ehrenberg.

Ophryoglena vorax. Sp.n. Plate L, Fig. 11.

Body obovate, compressed, elastic and persistent in shape,

more than twice as long as wide; body clothed with fine

vibratile cilia and longitudinally striate ; the oral aperture,

bearing a distinct vibrating membrane, is elliptical in shape,

parallel with the long axis of the body and located in the

anterior body-fourth, a little to the left of the median line ;

a pharyngeal passage continuing backwards in a straight line

NOTICES OF SOME UNDESCRIBED INFUSORIA. 61

and for some distance; contractile vesicle round, large, and

very near the center of the sinistral border; nucleus ovate,

very large, granular and obliquely placed subcentrally ; anal

aperture in posterior third of the ventral surface ; endoplasm

transparent, granular and usually containing an abundance

of diatoms and alge; no eye-like pigment spot ; reproduc-

tion by transverse fission ; movements slow and equable.

Length, I-100- to 1-60-inch; habitat, pond water with

alge.

This mammoth form is exceedingly voracious as its name

indicates. The writer has many times seen its body crowded

with diatoms and alge, filamentous and single-celled ; on one

occasion he counted six diatoms, a large closterium and many

smaller desmids.

FAMILY PLEURONEMID&, Kent.

GENUS CYCLIDIUM, Ehrenberg.

Cyciidrum.centralis. Sp. 0.. Flare ie wig. te.

Body elliptical from a dorsal view, and subovate from a

lateral view, about two and a half times as long as wide,

subcylindrical, the anterior half of the ventral surface com-

pressed ; body clothed with rigid hair-like-sete, not quite as

long the body width, and in even longitudinal rows, giving

it a striated appearance; a single long seta projecting from

the posterior border ; oral aperture located a little in advance

of the center of the ventral surface and supplemented by a

very capacious extensile membrane ; contractile vesicle cen-

trally placed, immediately behind the oral aperture ; nucleus

obscure, seemingly round and well up in the anterior body-

half; endoplasm transparent and granular; movements as

with Cyclidium glaucoma, Ehrenberg, but slower and more

deliberate ; reproduction by transverse fission.

Length, 1-550-inch ; habitat, pond water.

In a majority of specimens treated with a 5 per cent.

solution of acetic acid, a nuclear-looking body was detected

62 ;2G) SMITH:

well up in the anterior extremity, but as this was not con-

stant, the writer feels justified in writing ‘* Nucleus obscure.”

The large size of the infusorian and central position of the

contractile vesicle are diagnostic of this species. In its habits

it is not social as the Cyclidium glaucoma, nor has it the

frisky movements of this same species.

FAMILY BURSARIADA, Stien.

GENUS METOPUS, Clap..and Lach.

Metopus spiralis. Sp. n. Plate 1, Fig. 13.

Body subreniform, much compressed, not twice as long as

wide, soft and elastic, but persistent in shape, both extremi-

ties rounded ; a spiral bevel—which divides the zooid into

two unequal portions, the posterior of which is still more

compressed, narrower and thumb-like—originates at about

the posterior limit of the anterior body-third, on one lateral

border, continuing obliquely to about the posterior limit of

the central body-third on the opposite border, and from

there to the opposite surface and then obliquely to the pos-

terior limit of the border from which the spiral bevel origi-

nated, thus making a complete circle of the body; the

superior edge of this spiral bevel clothed with cilia much

longer than that covering the body, which is entirely covered

with fairly long cilia and longitudinally striated ; oral aper-

ture located in the spiral bevel, where it curves from one

surface to the other; contractile vesicle large, unstable in

shape and postero-terminal ; nucleus round to ovate, coarsely

granular, subcentral and near one lateral border; anal aper-

ture postero-terminal ; endoplasm yellowish and containing

in the anterior fourth a number of dark granules; reproduc-

tion by transverse and longitudinal fission ; movements rotary,

screw-like.

Length, 1-300-inch; habitat, pond water.

This interesting form has occasioned the writer much

trouble to diagnosticate correctly, its spiral-like movements

NOTICES OF SOME UNDESCRIBED INFUSORIA. 63

being very confusing. The position of the oral aperture is‘

unique and was ascertained only after feeding with carmine.

Longitudinal fission was at first interpreted as an act of con-

jugation, but further observation exhibited the complete pro-

cess, from inception at the posterior border to final separa-

tion. At times this form is very abundant.

FAMILY SPIROSTOMID&, Kent.

GENUS CONDYLOSTOMA, Dujardin.

Condylostoma culex. Sp. n. Plate I., Fig. 14.

Body somewhat purse-shaped, about twice as long as

wide, soft, elastic and slightly changeable in shape, anterior

a bit narrower than the posterior, much compressed and

obliquely truncate to dextral border; posterior inflated and

evenly rounded ; peristome field cleft-like, originating at the

truncated border and including the right-hand half, continued

obliquely towards the left, meeting the oral aperture at the

center of the lower limit of the anterior body-third; the

right-hand border of the peristome field bearing through its

whole length, a heavy and conspicuous undulating membrane ;

body covered in even longitudinal rows, with fine vibratile

cilia; body and peristomal cilia not diverse; contractile

vesicle in posterior body-third ; nucleus round and subcen-

tral; endoplasm clear and granular; movements rotary ;

reproduction by transverse fission.

Length, 1-365-inch; habitat, the gelatinous covering

of the eggs of the Culex mosqutto.

Owing to the absence of the extra large peristomal cilia,

which is characteristic of the genus Condylostoma, the writer

has some doubts as to the position of this form, and has

placed it with this genus provisionally. In no instance has

the writer found this infusorian outside of the habitat above

recorded.

64 F.C. SMITHS

FAMILY HALTERIID, Clap. and Lach.

GENUS STROMBI1D1UM, Clap. and Lach.

Strombidium nasutum. Sp.n. Plate I., Fig. 15.

Body subglobose, slightly longer than wide, the anterior

border produced in a rounded snout-like projection ; spiral

wreath of cilia and oral aperture as in Halteria grandinella,

Miller ; contractile vesicle conspicuous and in anterior body-

half ; nucleus roundish, coarsely granular, in the same body-

half and near the opposite border ; movements rotary, fairly

rapid and springing short distances at long intervals ; repro-

duction by transverse fission.

Length, 1-500-inch; habitat, pond water.

FAMILY GYROCORID&, Stien.

GENUS UROCENTRUM, Nitzsch.

Urocentrum trichocystus. Sp. n.

Body as Urocentrum turbo, Miller, a little longer than

wide, the anterior portion the larger; ventral surface, oral

aperture, contractile vesicle, nucleus, ciliary girdles, caudal

appendage and movements as in Urocentrum turbo ; tricho-

cysts abundant and conspicuous ; cuticle transversely striate

under a 1-6 objective ; endoplasm bluish-yellow ; reproduc-

tion by transverse and longitudinal fission.

Length, 1-300-inch ; habitat pond and ditch water.

This infusorian is often found in the company of the

ubiquitous Urocentrum turbo, and can be recognised quite

readily by the trichocysts, which hardly require any reagent

to demonstrate. On the application of the glycerole of

tannin the trichocysts are forcibly ejected from the body in

great abundance ; the average length of a number measured

was I-600-inch, which is comparatively very large.

NOTICES OF SOME UNDESCRIBED INFUSORIA. 65

FAMILY CHLAMYDODONTID&, Kent.

GENUS CHLAMYDODON, Ehrenberg.

Chlamydodon induratus. Sp.n. Plate I., Fig. 16.

Body plano-convex, much flattened, indurated, twice as

long as wide, the dextral border straight, the sinistral border

broadly convex ; dorsal surface traversed longitudinally by

from three to five flattened costz, the lateral borders finely

striate transversely ; ventral surface plane and covered with

fine vibratile cilia, which project slightly from the borders ;

oral aperture in anterior body-third, nearer the dextral bor-

der and supplemented by a pharyngeal rod-fascicle, lying

transversely, the cilia of this region very active; contractile

vesicle conspicuous and central; nucleus (?) roundish and

just below the contractile vesicle and near the dextral border ;

movements smooth and equable; endoplasm yellowish and

usually containing an abundance of filamentous alge.

Length, 1-300-inch ; habitat, ditch water with alge.

This infusorian is very voracious and has often been seen

filled with filamentous alge ; on several occasions a portion

of a long filament was swallowed and a large part was still

free, while the infusorian was dashing about as if in search

for more. The location of the nucleus is uncertain as in

many instances, after applying the usual reagents, this

element could not be detected.

FAMILY OXYTRICHID&, Ehrenberg.

GENUS OPISTHOTRICHA, Kent.

Opisthotricha elongata. Sp.n. Plate I., Fig. 17.

Body subelliptical, about four times longer than wide, soft

and elastic, the anterior wider and tapering gradually to the

posterior rounded border; anterior border slightly and

obliquely truncate to the dextral border; lip conspicuous ;

peristome extending obliquely to the oral aperture, which is

located in the center of about the posterior limit of the

66 NOTICES OF SOME UNDESCRIBED INFUSORIA.

anterior body-fourth ; the right-hand border of the peristome

bearing an undulating membrane ; frontal styles, six, arranged

in pairs, the two most superior ones uncinate ; ventral styles,

five, and scattered; anal styles, five, the two nearest the

dextral border the longest and just reaching the posterior

border ; marginal setz continuous, very much longer and

more numerous posteriorly, these setz on the sinistral side

beginning just above and near to the oral aperture and con-

tinuing obliquely to the posterior, where they project ;

caudal sete, three, central and lying parallel to each other

and to the longitudinal axis of the zooid; these sete are no

longer than the marginal sete of the same region; hispid

sete sparse and inconspicuous ; contractile vesicle subcentral

and near the sinistral border; nuclei two, one in each body-

half, to the left of the median line; movements rapid ;

reproduction by transverse fission.

Length, 1-100- to 1-80-inch; habitat, pond water.

Pp BTA

“+

Store Steals

eieg eyes SmRN poke SS eee

Rigaem whicmert i,

Fig.

NOTICES OF SOME UNDESCRIBED INFUSORIA.

PLATE I.

Petalomonas involutus.

Figs. 2,3 and 4. Astasia invaginata.

Fig.

10.

rite

rig

14.

15.

16.

17.

Heteronema lunaris.

Loxocephalus lucidus.

Nassula magna.

Holophrya curvilata.

Urotricha hyalina.

Tillina dissimilis.

Ophryoglena vorax.

Cyclidium centralis.

Metopus spiralis.

Condylostoma culex, ventral surface.

Strombidium nasutum.

Chlamydodon induratus.

Opisthotricha elongata, ventral surface.

THE SPORULAR DEVELOPMENT OF THE AMEBAE

VILLOSA, LEIDY.

J. C. SMITH, New Orteans, La.

In April, 1897, the writer secured some decayed leaves

from a pond in the Audubon Park, in New Orleans, and on

scraping a portion from one of the leaves, placing it under a

cover-glass, and then examining it with a one-fourth objec-

tive, the field was seen to be filled with a number of Amebe

villosa, Leidy.

Some of the specimens were active, some were apparently

on the threshold of encystment, while others had already

entered that state.

The field, fortunately, was entirely free of other forms of

amebz, as well as of the troublesome Paramecium, Rotifera

and worms.

For a while the field was thoroughly examined, and the

writer noticing something unusual about the amebe, con-

centrated his attention on one of the forms that had become

quiet and was evidently about to become encysted. This

specimen measured 1-175-inch, displayed the posterior well-

covered with the villous processes which are diagnostic of

this specie ; the endoplasm contained a number of linear

bodies and some food-balls already changed in color ; the

contractile vesicle was large and active, and instead of the

usual nucleus, there were from ten to fifteen nuclear-looking

bodies that moved freely in the endoplasm in unison with a

slight contraction and expansion of the body. These

nuclear-looking bodies were evenly dispersed, of a bluish

tint, globular, very granular and in size varied from 1-2750

7O Jee AC aeratsT ss 8a g OF

to 1-1800-inch. The slight contraction of the body became

fainter, and in about one hour there was a rapid movement

of the contents of this specimen, to the posterior extremity,

and at the same time a rupture of the seemingly dense

ectoplasm of this part; a number of the nuclear-looking

bodies, in company with the linear bodies and food-balls,

were ejected from the body with considerable force, sending

them a distance from the body, equaling one-half of its long

diameter. The ameba now seemed to collapse and the

contractile vesicle disappeared.

The writer's attention was now confined to the nuclear-

looking bodies that lay scattered about. In the course of a

few minutes, the granules contained in these bodies became

partially concentrated in one place in contact with the

ectoplasm, and was of a deeper blue in color; this concen-

tration of the granules left more than one-half of each body

almost clear and transparent, and in this clear space there

appeared simultaneously with the concentration, a very

minute but distinct pulsating vesicle; in a short time a

slight movement of the body was detected and there

appeared a flagellum equaling in length from four to five of

the body’s diameters, and was directed stiffly forward ; the

body now became very active and in a few seconds darted

off ina rapid chase about the field, in an aimless manner,

reminding the writer of the zoospores of the Achlya prolifera.

Casting a glance at the other free nuclear-looking bodies, it

was seen that most of them were undergoing the same

change, and they were kept under observation until they had

all disappeared from the field, in the same manner. It was

impossible to follow any one of these zoospores, as the field

had become filled with them.

The writer now confined his attention to one of the

encysted amebze. The one selected measured I-250-inch,

possessed no trace of a contractile vesicle, no food balls, a

few of the linear bodies, some of the nuclear-looking bodies

and nothing that could be differentiated as the original

SPORULAR DEVELOPMENT OF AMEB VILLOSA. Fh |

nucleus ; the nuclear-looking bodies were granular, as the

ones cited above, and instead of being free in the endoplasm,.

were congregated in five spherical masses, each mass being”

composed of from four to six units and was enclosed in a

very distinct membrane, which was made even more distinct

by adherent granules.

In a short time and without any apparent movement of

the body, three of these spherical masses were thrown out

with some force, the fissure in the ectoplasm of the encysted

ameba was not closed, and the whole form collapsed, still

containing two of the masses.

In about fifteen minutes after being ejected, the mem-

branous coverings of the units were ruptured and the con-

tained nuclear-looking bodies were freed.

The average size and appearance of these bodies were the

same as the ones seen discharged from the ameba first

recorded.

In the course of a few minutes they were seen to go

through identically the same phenomena as was observed to

take place with the one first mentioned.

The field was now filled with these zoospores, and being

free from all other forms of life, offered a good opportunity

for further study.

In about three hours after beginning the observation some

of the zoospores had slackened their movements, would come

to a halt for a short time, and then start off again; a num-

ber were less active than the rest and very soon became

quiescent. Selecting a quiet specimen that measured I-2000-

inch,.and using a one-eighth objective it could be distinctly

seen to elongate itself and then resume its original size ;

would throw out a single minute lobate process now from

one side and again from the other side. The dark blue mass

of aggregated granules, first observed in the nuclear-looking

bodies after they had been ejected from the ameba, had

become much smaller and now represented the nucleus, the

contractile vesicle was very distinct and the intervals between

72 J[s°C.)-SMEEE:

diastole and systole were short. This extrusion of lobate

processes was witnessed for some time, and it was noticed

that there was no change in the position of the young

ameba, but that after awhile it retained the elongate form

and would throw out pseudopodia from all parts of its body

that would at times exceed the length of the zooid; at these

times it had the appearance of a minute Ameba proteus.

Many of the forms measured now as much as I-90o-inch,

without the pseudopodia. The hour being late, the slide

was carefully prepared and put away with the view of con-

tinuing the observation on the following evening.

On resuming the observation, nineteen hours afterwards,

the field was found strewn with a very large number of

small and active amebz that differed from the larger forms

of Amebe villosa, only in the absence of the villous pro-

cesses ; the endoplasm was slightly granular, the nuclei and

contractile vesicles as distinct as in the large forms; they

were freely moving about and extruded only the lobate pro-

cesses. Measurements showed them to range from I-800 to

1-550-inch.

In two places on the slide were a number of forms, from

ten to fifteen, closely huddled together, as if dropped in a

mass at that place. In size and shape they were the same

as the free moving ones ; the nuclei, contractile vesicles and

anterior clear spaces were exceedingly distinct ; they had a

slight movement on and alongside of each other, without

seeming to increase the space occupied by them. They

reminded the writer of a litter of kittens a day or two old.

The writer in speculating on this phenomenon, came to the

conclusion that those nuclear-looking bodies that remained

in the ameba after a part had been ejected, were developed

within the confines of the body, and were freed only after

the dissolution of the firm ectoplasm, and in this way the

clusters of amebz were produced.

The slide was now again laid aside, and on resuming the

observations, eighteen hours afterwards, very few forms

SPORULAR DEVELOPMENT OF AMEBZ VILLOSA. 73

were found, and they differed in no way from the forms seen

the evening before. The writer believes that if food could

have been supplied, the observation could have been

extended so as to witness the full development of these

young forms.

The literature on the development of the ameba, in the

possession of the writer, is very limited, and from it he gleans

that up to 1891 the sporular development of these lowly

forms was only glimpsed, and was not worked out as fully

as has been done in this case.

To make this history of the sporular development of the

Amebe villosa (and by inference all amebez) complete, there

is only one essential requisite, and that is to trace the origin

of the nuclear-looking bodies to the nucleus.

SOME POINTS ON CLEAVAGE AMONG ARTHRO-

PODS.

AGNES M. CLAYPOLE, M. S., Pu. D., WELLESLEY, Mass.

In the development of an animal from the egg to the

hatched form one great problem has alwaystobemet. That

problem lies in the development of a multicellular animal

from a unicellular element. For every egg is in its essential

structure of this simple type—it is composed of a cell-body

and nucleus. Other modifications in the form of membranes,

shells, envelopes of any kind and even food material or yelk

are secondary. Since all animals, with the exception of cer-

tain plant-like forms and unicellular organisms, develop from

eggs, there is in the course of development of every indi-

vidual this great transition from a single-celled egg to a many-

celled adult.

Details of the processes by which this transition takes place

are many and varied within the wide limits of the animal king-

dom, but the same principle controls the process throughout.

The means by which the single-celled egg becomes a multi-

cellular structure are known under the general name of cleav-

age. The egg divides into two parts, which may be equal or

not, varying with different kinds of eggs. The subsequent

division of each of these parts into two and these again into

two increases the number of cells in the developing egg in

geometrical ratio, the ultimate result being a many-celled

embryo, having eventually the many tissues and organs that

compose the adult body.

While the process can.in general be called by the same

name, ‘‘cleavage,” in all types of animal life, there are many

SOME POINTS ON CLEAVAGE AMONG ARTHROPODS. 75

fundamental differences in the details and comparing extreme

cases it is difficult to see how the varied methods found can

be in any way connected. However, the existence of very

different methods of cleavage among closely related forms of

animals demands the bridging of these gaps and the clear

understanding of transitions from one type to another. In

ultimate analysis, these differences in the first stages of

development are found to depend on a single fact, which

may be stated briefly as the amount of food material or yelk

present in the egg in proportion to its size. This is the key

to the law which controls the early form of the superstruc-

ture, as it rises by the process of cleavage.

The greatest variation, within close limits, seems among

the large sub-kingdom of invertebrate animals, and among the

invertebrates no class offers a more interesting and profitable

field of study than the Arthropod, including as it does insects,

myriapods, crustaceans, spiders. Among the crustaceans

many forms of cleavage are found. Some of the lower

groups show the most primitive type, the eggs being holo-

blastic in their cleavage. In this process the egg is cut

directly into two equal or approximately equal parts, which

again divide and their products divide until a mass of equal

or approximately equal cells result. Each cell contains a

nucleus surrounded by some cystoplasm and some _ food

material or yelk. The method of forming a multicellular

animal from a unicellular egg in such a case is, in its early

stages, controlled by a single law—that of cell-division, some-

times equal, sometimes unequal; but cells of the early stages

arise by complete division of the egg and those of the latter

by complete division of the preéxisting cells. This kind of

cleavage is found to occur only in those eggs having a small

amount of equally distributed yelk or food material. This

in turn limits it to eggs of a small size and nearly or quite

spherical form.

Passing now to the Insecta, the highest of the Arthropods,

very different conditions are found to prevail. The eggs

76 AGNES M. CLAYPOLE :

of most of the Insecta are larger in proportion to the

size of the animal than among crustaceans, contain more

yelk and are usually either oval, disc-like or curved-rod-

shaped. The result of all these modifications is to greatly

modify the kind of cleavage. Instead of any such process

as has been described, the centrally placed nucleus divides

repeatedly with no division of the surrounding yelk mass,

which is placed in meshes of an extremely attenuated net-

work of protoplasm. The nuclear division proceeds on

exactly the same principle as that on which the whole egg

segments in the holoblastic cleavage. This continues until

a large group of nuclei has been formed in the middle of the

egg (Fig. 1). These nuclei, owing, in part at least, to their

increasing number, migrate toward the surface of the egg

and eventually form a uniform layer of nuclei over the sur-

face, imbedded in a rather thick layer of protoplasm that has

always covered the egg surface. Finally, cell outlines appear

between the nuclei and a blastoderm, one cell in thickness is

formed, enclosing yelk, as yet uncleaved. At the end of

blastoderm formation, however, the nuclei are not all ina

peripheral position, a certain number are scattered equally

through the yelk. Later, the yelk breaks up into a number

of masses, in the center of each being a nucleus, one of those

previously scattered through the yelk. This secondary yelk

cleavage, as it is known, is the retarded expression of holo-

blastic cleavage, the only point in the development of such

an egg that suggests the simple holoblastic type. This, then,

is the typical form of cleavage among insects, nuclear and

protoplasmic division, leaving the yelk mass intact until a late

stage.

There is a group of insects very lowly in their organisa-

tion that have been as yet but incompletely studied, even by

the systematist. These, the Apterygota by name, form a

large group of mostly small wingless insects, remarkable for

their generalised characters. The commonest and most

familiar of this group is Lepisma or the ‘‘silver fish,” well-

SOME POINTS ON CLEAVAGE AMONG ARTHROPODS. 7.

known for its destructive habits in eating paste from the book-

bindings and other similar acts. Although the systematic

zoologist has subdivided the whole group into well-marked

sub-groups and many different speciés are recognised, yet

the embryology has remained for a long time untouched, with

the single exception of a few observations of surface changes.

With the increase in nicety of microscopical technique and

improvements in the microscope, the difficulties of handling

and studying eggs of extremely small sizes and delicate com-

position have been so reduced that a careful study of the

minute eggs of members of the group Apterygota is now

possible.

It has been my privilege to undertake an investigation

into the embryological development of Axurida maritima, a

small member of this group, widely scattered over the coast

on both sides of the Atlantic ocean. These animals live under

rocks and stones on sandy sea beaches, at such a level as to

be completely submerged twice a day by thetide. The eggs

of this minute animal, itself only about three to four milli-

meters in length, are larger in proportion than those of any

other members of the group whose eggs are as yet known

and hence offer better advantages for study. A Frenchman,

Lemoine, published an account of the external features of

the eggs and some stages of the embryos of form allied to

Anurida and announced that the cleavage was holoblastic

and approximately equal. The investigations on Anurida

confirmed this statement in every way and with the added

help of serial sections some interesting points were made out.

The egg instead of having any of the forms already des-

cribed as typical for insect eggs is strictly spherical and con-

tains a considerable, but not a large, quantity of yelk. The

first and second cleavage planes are vertical, and the third

horizontal, as is usual in holoblastic cleavage. . The cells

mass together from the beginning, and the result is a solid

morula instead of a hollow sphere surrounded by a single

layer of cells. When the cells are reduced to a uniformly

78 AGNES M. CLAYPOLE:

small size by rapid divisions a change takes place in the

method of cleavage. (Fig. 2.) The blastomeres, which up to

this point have been distinct from each other, about equal in

size and containing approximately equal amounts of yelk,

begin to lose their distinct outlines. The nuclei surrounded

by small masses of protoplasm slowly migrate outward toward

the surface of the egg. During the process the nuclei and

their surrounding masses of protoplasm divide repeatedly,

and ultimately a layer of cells covers the surface of the egg,

forming a uniform blastoderm of rather large cells. Asa

final result, after continued divisions, two of the primary

germ layers are clearly established, an outer one of uniformly

small nuclei imbedded in a common layer of protoplasm and

showing no separation into separate cells, the ectoderm, and

an inner one close below the ectoderm, composed of larger

nuclei, lying in an equally undivided layer of protoplasm, the

mesoderm. Inside, scattered through the yelk, are cells that

have two different destinies. The yelk, after the migration

of the nuclei and their surrounding masses of protoplasm,

loses its cleavage and becomes a solid mass, containing

scattered nuclei. Secondary yelk cleavage never appears.

In Anurida, then, we find several interesting points that

connect the curious type of cleavage found in the eggs of the

Insecta and known as centrolecithal cleavage with the simpler

holoblastic type. These facts are:

1. Holoblastic, nearly equal cleavage exists in the early

stages.

2. Ata later stage holoblastic division is lost and the

formation of the blastoderm takes place by the migration to

the surface of the nuclei, surrounded by small masses of. pro-

toplasm.

3. No secondary yelk cleavage takes place.

The existence of these transitional characters in an animal

as lowly as Anurida, standing at the bottom of the great

and specialised group of insects, is'extremely significant.

It points most clearly to the derived nature of the complex

SOME POINTS ON CLEAVAGE AMONG ARTHROPODS. 79

type of cleavage, characteristic of the group. It designates

the holoblastic type as belonging to insect ancestors and helps

by just so much to indicate possible lines of ancestry. Not

only the cleavage, but other points which cannot be discussed

here, as the absence of the embryonic envelopes, amnion and

allantois, the presence of a series of membranes shed from

the embryonic surface and the existence of a large glandular

_organ, similar to one of the many organs known as a ‘‘ dorsal

organ,” lead to a closer alliance of the insect race with crus-

tacean or myriapod ancestors.

One point is indeed settled, that the Apterygota show

truly generalised characters and may be considered closely

similar to the primitive insect ; their lowly characters are not

entirely due to degradation, but in part to direct inheritance

and non-progression.

Returning to the question of cleavage, it is interesting to

note among many of the arthropod groups transitional forms

from the holoblastic to a more complex type of cleavage.

In Korschelt’s and Heider’s text-book of embryology, the

crustacea are classified according to their cleavage and a

large group is made of those forms in which holoblastic

cleavage exists at the beginning of development and a

change comes in later. Brauer’s figures are given for the

crustacean Branchipus in which the change takes place in the

following way: Holoblastic cleavage results in a distinct and

regular central cleavage cavity. By repeated divisions a

layer of small, narrow and much elongated columnar cells

results, having the nuclei on the periphery and the long yelk-

filled stems extending intothe center. Eventually this inner

yelk-laden part forms a fused mass, continuous, however, with

the small outer blastoderm cells. (Fig. 3.) Among the Pan-

topoda there are two methods of cleavage, the one showing

total cleavage at first, followed by a migration of all the cleav-

age nuclei to the periphery, with the ultimate obliteration of

all cleavage planes in the yelk mass. Another type shows

holoblastic cleavage up to the sixteen celled stage with the

80 SOME POINTS ON CLEAVAGE AMONG ARTHROPODS.

formation of a distinct central cavity. Later the-entoderm is

formed by delamination of the inner part of the cells, giving

rise in this way to the inner germ layer by a method of

multi-polar migration. |

Among the myriapods purely centrolecithal cleavage pre-

vails, accompanied by a fragmentation of the yelk mass,

that from the surface strongly suggests holoblastic cleavage.

The central nuclei finally migrate to the periphery along

these lines of pseudo cleavage. (Fig. 4.)

These few facts show how wide-spread among arthropods

are such changes during cleavage. But a passing reference

can be made to the important bearing such changes have on

the allied questions of development. This variation causes

the inner germ layer or entoderm to be formed sometimes by

invagination, sometimes by delamination and at others by the

commonest method of cell migration from a definite point or

points.

In this way the bearing of the question of the origin of

the great primary germ layers is shown to be intimately con-

nected with the form of cleavage prevailing in the develop-

ment of the organism, and the value of any contribution on

the point, however small, is indicated.

82 SOME POINTS ON CLEAVAGE AMONG ARTHROPODS.

PLATE I.

Fig. 1. Typical insect cleavage.

Fig. 2. Anuridan cleavage.

Fig. Crustacean cleavage.

Fig 4. Myriapod cleavage.

THE COMPARATIVE HISTOLOGY OF THE DIGESTIVE

TRACT.

EDEEL j- CLAY POLE. Pu baVimor

The idea of the evolution of the complex from the simple

has never been more prominently before the eyes of the

scientific world than it is today. It has become, as it were,

the underlying working hypothesis in almost every line of

research, turning attention strongly toward the questions sur-

rounding the origin of adult and highly differentiated struc-

tures from preéxisting simple types. The internal structures

of animals, though useless for establishing specific or even

generic differences, yet afford a basis for the establishment

of certain broad Azstorzc relations, which indicate the path of

the past development of the race. This has been long shown

to be true of the gross form of parts, but the application of

the same principle to histological variations is not so general.

It is from this point of view that I wish to discuss the digest-

ive tract, which is chosen simply because it is so well known

in the higher types and more readily worked up in those

concerning which literature is notso abundant. Many points

are as yet incomplete and this presentation must be consid-

ered, more in the line of suggestion than as a treatise on the

subject.

The forms chosen cover as wide a field as possible from -

the mammals to the fishes, though, personally, I could exam-

ine and section the tissues of one representative of each

class, excepting in the case of the Amphzbza. There are the

Mammalia, from which the cat is taken; the Aves, repre-

84 EDITH J. CLAYPOLE:

sented by the pigeon; the Refpéz/ia, for which the turtle

stands ; the Amphibia, a group containing many divergent

forms, can be far more easily obtained and, besides, the frog

(Rana catesbiana), the mud puppy (Vecturus maculatus),

the mud dog (Cryptobranchus alleghaniensis) have been used.

Of the Pzsces, the work of Dr. Hopkins, of Cornell Univer-

sity, gives the structure in American Ganoids and other forms

can be used readily. The Lamprey Petromyzon is added to

the list and completes it. Many more could have been

chosen had time afforded, but these must stand to show a few

general points of interest.

Mammatia.—The structure of the digestive tract in this

class is so familiar that it is only necessary to give the essen-

tial characters with no detailed description. Though subject

to wide variation, due to differences in food, in the main the

same plan of structure persists in all. Epithelium lying on

a basement membrane lines the whole tube ; from the lips to

the stomach stratified squamous cells are present; from the

stomach to anus the simple columnar cell forms the unit of

structure. Certain modifications exist at definite points.

1. The respiratory part of pharynx (to soft palate) is

lined with stratified columnar cells.

2. The cardiac gastric glands of the stomach have the

parietal or acid cells, so important in aiding the rapid diges-

tion of fibrin and albumen. |

3. The small intestine has its surface thrown into villi,

which are covered with striated epithelial cells, especially

active in absorption.

4. <All the parts of the tract are quite sharply marked

off from each other (excepting the mouth and pharynx).

Aves.—TYhe birds are the nearest existing allies of the

mammals and although they represent an extreme develop-

ment from a more primitive stock, have at least warm blood

in common with their brother man. Almost as various forms

are found here as among mammals, the variation being due

to the same cause—variation in food. Both grain-eaters and

COMPARATIVE HISTOLOGY OF THE DIGESTIVE TRACT. 85

meat-eaters exist in this class and since in the laboratory the

pigeon is the bird most easily obtained in the proper condi-

tion for examination, it is on this form that the following

facts are based :

As before, the whole tract is lined with epithelium ; from

the mouth to stomach stratified squamous cells cover the

surface ; the respiratory part of the pharynx shows the same

difference. Inthe pigeon, and grain-feeders generally, the

esophagus dilates into a crop, not a glandular organ, the

so-called pzgeon's milk being the cast off and disintegrating

epithelial cells. The differentiation of the stomach into two

organs, one glandular, the other muscular, brings in a little

change in structure at this point. The proventriculus or

true stomach has only a chemical function. It is set thickly

with glands, which are changed from the simple tubular of

the mammal to compound tubular of a complex form, a large

number of small tubes opening into one common duct. In

the most complex form there is almost a suggestion of chains

of cells, so closely do the adjacent tubes lie against each

other, only a single row of connective tissue cells lie

between. The deep-lying cells are the usual polyponal

secreting cells. This apparently great modification from

the simple tubular glands of the mammals is merely a

device for saving space and for putting a large secretive area

in asmall organ. Since the food is not here subjected to the

grinding and mixing process, there is no reason for the part

to be large, it is merely a glandular structure, in passing

through which the food is bathed with a juice, powerful in

chemical action. The change from the esophagus to stomach

is very gradual ; above the crop the walls are entirely free

from glands; between crop and proventriculus mucous

glands appear, becoming larger toward the latter part. They

are compound tubular structures, the mouth being lined with

low cuboidal celis, while the deep-lying secreting gland

tubes are formed of the usual polyhedral cells. As shown

from the light stain taken if hematorylin is used, they are

86 EDITH <J, -CLAYPOLE :

mucous glands. The surface is covered with a layer of

stratified squamous cells, which grows thinner as the stomach

is approached. Finally, these are replaced by the simple

columnar cells, characteristic of this organ. At the same

time the complexity of the gland increases and the cells

change from mucous to serous for the secretion of the true

gastric juice.

This gradual change in the glands is very suggestive of

the manner of development of the large glands in the body

from their originally single tube or sac; it gives almost a

bird’s eye view, as it were, of the transformation, by tracing

the change in these from the crop to proventriculus.

In the gizzard the surface is protected by a hardened

layer, formed as a secretion from the underlying cells, which

are simple columnar, as in the stomach. The function of

this organ is a purely mechanical one, hence the great

development of the muscle coats surrounding the hardened

mucous layer. The intestine differs but slightly from that of

the mammal, the muscle coats are very thin, the mucous

surface, lined with simple columnar striated cells, is thickly

set with villi from the gizzard to cloaca. At first tall and

slender they gradually become shorter and thicker, disappear-

ing entirely in the neighborhood of the cloaca.

The notable differences are the following :

1. Development of compound tubular glands in the lower

part of the esophagus and stomach.

2. Villi reach through intestine to cloaca, usually disap-

pearing there.

3. Loss of distinctness between certain parts, z. @.,

esophagus and stomach, large and small intestines.

Repttles.—But one reptile can stand here to represent the

class, the Turtle. So that exception to the following facts

may be taken if some other form were chosen. The turtles,

however, show some interesting variations. The mouth in all

forms is lined with stratified squamous epithelium, which at

times is replaced by stratified columnar apparently without

COMPARATIVE HISTOLOGY OF THE DIGESTIVE TRACT. 87

any definite cause. If there are many papille or similar

structures in the mouth, according to Machate, they are

liable to be covered with stratified squamous, while stratified

columnar cell line the vallies between. If the mouth is horny

at all, then the epithelium is always of the stratified squamous

form.

In the esophagus there are two distinct structures found.

All the great sea turtles (Hoffmann) have in the esophagus

peculiar horny papilla, which may extend even into the

stomach. In these forms the esophagus and the papille,

even those in the stomach, are coated with stratified squamous

epithelium. In all other turtles the esophagus is lined with

stratified, columnar, ciliated cells, and mucous glands are

largely developed. In both cases the muscle of this part of

the tract is the plain kind, as in the birds.

There is no sharp definition between the esophagus and

stomach, but where the characters of the latter are well

established they are seen to be not unfamiliar. The cardiac

glands are simple, tubular in form, the pyloric ones being

wider in mouth and less deep. Simple columnar epithelium

covers the surface and there is a total lack of peptic cells.

The cells do not vary much in appearance, but no doubt

physical and chemical differences exist among them.

The intestine begins with a very sudden decrease in size,

inside, the mucous coat is thrown into longitudinal folds. The

simple columnar epithelium of the stomach is continued into

this part ; among the columnar cells is a varying number of

goblet cells. But there is a total absence of v7z//z, so charac-

teristic of the small intestine in both birds and mammals.

Glands are present in some families of turtles and absent in

others. In the one studied (Chripenny picta) very small

tubular structures were found. The change from stomach to

intestine is sudden, the pyloric glands abruptly ending, the

structure of the intestine appearing. The large intestine is

like the small, except that the walls are thinner. The cloaca is

marked by a large amount of pigment and large mucous glands.

88 EDITH J. CLAYPOLE :

Several significant changes appear here :

1. Presence in some forms of ciliated columnar epithelium

in esophagus as well as respiratory tract.

2. Absence of villi in all forms.

3. Excepting for the division between the stomach and

small intestine and the large and small intestines all the parts

are indistinctly separated from each other.

Amphibians.—In this comprehensive group we reach the

parting of the ways. To even more generalised forms than

these, we must look in past ages to see the origin of the higher

types. Some few of the old-fashioned forms no doubt, with

small changes in fashion, have lived on and are now included

among this group. Hence our interest in them is great.

They show extremes of type, as in the frog and toad on

one hand and the simple, primitive (sub-salamander) Mecturus

on the other. The gross structure of the first form is some-

what similar to that of the turtle—a large, wide mouth and

esophagus, merging gradually into the narrow stomach, this

somewhat sharply passes into the small intestine, which also

is fairly distinct from the short, broad, large intestine. In

Necturus, the other extreme, the short, wide esophagus

passes insensibly into a stomach not very much larger; this,

in turn passes quite gradually into the small intestine.

There is no large intestine, the small one opening into a wide

cloaca.

Summarising these forms as well as possible, we find the

following points of structure :

There are two types of mouth lining and esophagus :

1. All purely aquatic Amphzbzans have, according to

Kingsbury, stratified squamous epithelium. A layer of but

four to five cells, however, in the mouth; in the esophagus

these are replaced by simple columnar ciliated cells.

2. All the remaining land and semi-land forms have the

roof of the mouth and the esophagus covered with stratified

ciliated cells, while the tongue and floor of the mouth are

protected by stratified squamous epithelium.

COMPARATIVE HISTOLOGY OF THE DIGESTIVE TRACT. 89

A gradual transition from esophagus to stomach brings

us to the usual structure, simple columnar cells and the

characteristic tubular glands. The change from simple

columnar ciliated to the non-ciliated form in the purely

aquatic Amphibians. makes but a slight difference between

these organs. There are no acid cells in Necturus and its

allies, and it is yet an open question whether they exist in

the frog.

The small intestine is not widely different, a tube lined

with the simple columnar cells, in some forms showing tubu-

lar glands, in others not. The large intestine, if present, is

practically the same, except for an increase in the number of

mucous cells. The cloaca is in some forms ciliated, in others

lined with stratified columnar cells. The changes to be

noted here are :

1. Introduction of simple epithelium in esophagus of

some forms.

2. Increased indefiniteness of gross parts (esophagus,

stomach, intestine).

3. Very great increase in size of cellular elements.

There is one class yet to be mentioned, also an ancient

race, that of the Ganoid fishes. From Dr. Hopkins’ work on

the American Ganoids we find the following points estab-

lished :

As far as the pneumatic duct or opening of the air cham-

ber into the mouth, the mucous coat consists of stratified

squamous cells; from there simple columnar ciliated cells

take their place until two to three centimeters from the

pyloric part of the stomach, when the cells become non-

ciliated. Gastric glands are present for the first time in the

class ‘‘ fishes.”

One word for the lamprey, as shown by Claypole. In

them the whole enteron, from mouth to cloaca, is lined with

simple epithelium ; no stratified layer appears at all. The

esophagus shows simple columnar and the intestine ciliated

areas of columnar cells intermingled with non-ciliated masses.

gO EDITH J. CLAYPOLE:

We have here before us the evolution of the mammalian

alimentary tract. From a simple straight ciliated tube it

passes through both cellular differentiation and gross differ-

entiation, until the adult enteron; with all its complexity of

parts and structures, is complete. Ciliated epithelium is

primitive and in the adult mammal is present, as we have

seen, only in the respiratory part of the pharynx. In birds

the same is true. In turtles one group agrees with the fore-

going types, while the second gives us ciliated stratified cells

in the esophagus. Amphibians show practically the same

distribution of these cells as in turtles, with an added ciliated

area in the roof of the mouth in land forms. Ganoid fishes

extend the area for ciliated cells to the stomach also, but

omit them in the mouth, and among the Cyclostomes the

whole intestinal tract is more or less covered with these

primitive elements. But one cause can account for this

almost complete banishment: the demand for rapid absorp-

tion in the quick-moving, active animals, to repair the waste

of such activity makes the necessity great for surfaces cov-

ered with columnar striated cells in those parts where such

processes take place, z. ¢., stomach and intestines. The

protective coat of stratified squamous cells is essential also

in the smaller, longer tubes, which serve as the esophagus

among birds and mammals. The development of villi in

birds and mammals is another answer to the demand for

absorptive area.

One even more significant point remains, that is the size

of the elements in the various forms. It is a striking fact

that in ascending the scale of life among animals, there is a

very general loss of size in the cells of the body. The gen-

eralised Amphzbians show us the largest cells known—Am-

phiuma, Necturus, Cryptobranchus, frogs and toads show a

fair graded series in size. Among turtles they are still large,

considerably smaller in birds and smallest of all among mam-

mals. Inthe Plate this fact is illustrated in Figures 1-5. The

cells lining the small intestines were chosen to represent this

COMPARATIVE HISTOLOGY OF THE DIGESTIVE TRACT. QI

truth since of all the parts of the digestive tract this one

perhaps is subject to least variation in structure and function.

The cells were drawn to scale and from specimens similarly

prepared. They need no further explanation.

The story is but that of the change from a colony of a

few large, not highly specialised units, into one composed of

very many small, but more highly specialised. By this

decrease in size two important points are gained: rapid

removal of formed compounds, both waste products and use-

ful substances and rapid additions of new materials, and oxygen

can be rapidly obtained from the circulating blood and in all

ways far more rapid transportation is accomplished. From

this point of view the practical necessity for a change of size

in all the cells in the body becomes apparent. Each one

gains equally in effecting complete and rapid removal of waste

and the results are beneficial to the whole organism, resulting

in a heightened power of adaptation to the needs of life.

REFERENCES.

1. 1890. Bronn—Klassen und Ordnungen des Thierreichs (Reptilien). Bd.

Vie hh

2. 1891. Bronn—Klassen und Ordnungen des Thierreichs (Végel). Bd.

Wile sede livis

3. 1894. Claypole, Agnes M.—The Enteron of the Cayuga Lake Lamprey.

Proceed. Am. Mic. Soc., 1894.

4. 1893. Hopkins, G. S.—The Enteric Epithelium of Amdza calva. Wilder

Quarter Century Book, 1893.

5. 1895. Hopkins, G. S.—The Enteron of American Ganoids. Journal of

Morphology, Vol. XI, No. 2.

6. 1894. Kingsbury, B. F. The Enteron of Necturus maculatus. Pro-

ceed. Am. Mic. Soc., 1894.

Q2 COMPARATIVE HISTOLOGY OF THE DIGESTIVE TRACT.

PLATE lI.

Fig. 1. Vertical section of intestinal epithelium of cat, showing high

columnar cells with a striated border.

Fig. 2. Vertical section of intestinal epithelium of pigeon. Same parts

shown as above.

Fig 3. Vertical section of same part in turtle.

Fig. 4. Vertical section of frog’s intestine.

Fig. 5. Vertical section of intestinal epithelium of CryAtobranchus.

All these sections are from tissues similarly prepared so as to give uniform

conditions of hardening, etc. The cells show more or less distinctly the

striated border characteristics of absorptive cells.

Figs. 6, 7 and 8, are vertical sections of the esophagus of the cat, turtle

and pigeon, showing the stratified squamous cells in the two warm-blooded

cells and the stratified ciliated columnar cells in the turtle.

A COMPARISON OF THE PHAGOCYTIC ACTION OF

LEUKOCYTES IN AMPHIBIA AND MAMMALIA.'

JOHN M. BERRY, PErTersorRO, N. Y.

The property possessed by leukocytes of ingesting foreign

particles, and known as phagocytosis, is one that has excited

a great deal of attention in scientific research. This property

of the leukocyte is particularly interesting from a pathological

standpoint. The fate of foreign matter which enters the

body, the taking up of broken down blood corpuscles, the

carrying of dust particles from the lungs, leading to what

Ziegler has called dust diseases, and the elimination of bac-

teria from the body, are all phenomena depending upon this

property of the corpuscle. Metschnikoff would affirm that

through the phagocytic activity of the corpuscle toward

infecting bacteria the body is able to resist their attack, and

that it is to this property that we owe our immunity to certain

diseases.

Many experiments had been performed and a great many

articles had been written as to what was the fate of foreign

particles introduced into the body. The methods of experi-

ment differed in a great many cases and the results obtained

were as varied and original as the methods. In 1893 Miss

Claypole, then at Cornell University, devoted a part of her

thesis, for the master’s degree, to a discussion of this question.

Hitherto the manner of experimentation had been such as

to be almost certain to bring on pathological conditions, but

1. This paper gives the main results of the work done in the preparation of a bacca-

laureate thesis in the Department of Histology and Embryology in Cornell University during

the college year 1896-97. My thanks are due the department for the abundant material and

facilities put at my disposal, and for the advice and encouragement from the instructing staff.

94 JOHN M. BERRY:

in Miss Claypole’s work the animals were kept under normal

condition as much as possible, and were subjected to such

experiments only as they could meet in a physiological

manner. The great fault in previous experiments had been

in the quality and quantity of foreign matter used. In some

cases such a heavy substance as powdered sandstone was

introduced into the body, and in almost every case too much

of the foreign matter was introduced. Miss Claypole used

for her experiment Vecturus and Cryptobranchus. The foreign

matter that she used was a mixture of

Lampblack = 22) 1 2A SS Bese ee nae ee

GumPArabicus.<-- tf aeene ere Gece ede Pe ae ee Ig.

Sallitycs occa lees Wels Gn haa pane gies Sure Pepe 6-10 g

Water tem cite a hoe aoe meee Te seuss gn ae 2 OIC es

At no time did she inject more than 1c.c. She introduced .

the carbon into the jugular vein, or into the abdominal cavity.

The results of Miss Claypole’s work were as follows:

When the injection was made into the abdomen the carbon

appeared in the circulation in from six to nine days. When

the injection was made into the jugular vein the carbon

appeared in the abdominal cavity. In case of abdominal

injection no free carbon was found after the fourth day, and

in case of venous injection after the second day; in both

cases the carbon was ingested by leukocytes. In the tissues

Miss Claypole found that there was:

1. No free carbon.

All the carbon was in leukocytes, except in the spleen.

3. Carbon-laden leukocytes extra and intravascular,

except in liver, where carbon was only intravascular.

4. Ingested free cells on mucous surfaces.

5. Ingested cells with excretory products in kidney.

6. Ingested cells free in lungs.

Miss Claypole’s view was that ultimately all the carbon

would be removed from the body, with the possible exception

of that in the spleen by the wandering out of the carbon-

laden cells.

LEUKOCYTES IN AMPHIBIA AND MAMMALIA. 95

I have followed out Miss Claypole’s method in my experi-

ments, using the Necturus first as a comparison to her work

and then going on to mammals. _ By reason of the facilities

now possessed by the department of histology and put at my

disposal, I was able to keep the animals under almost normal

conditions and for a long time. I could, therefore, carry

on my experiments a much longer time than Miss Claypole.

She did not keep any animal more than eighteen days after

injection, and while I found the same results as she did with

animals kept for only that length of time, when I used animals

that had been kept for a longer time I found the phenomena

to be not so definite and her simple conclusions not in all

cases justified. The Vecturz used for experiment gave the

following results:

NECTURUS. I

October 14, 1896, I injected about one third c.c. of the

carbon mixture into the abdominal cavity. The animal was

examined several times under the microscope, but no carbon-

laden leukocyte could be seen circulating in the gills up to

October 26th, twelve days after injection, when the animal

was killed. Sections were obtained of the liver and kidney.

There was no free carbon anywhere, all found being enclosed

in leukocytes. The liver showed carbon at the periphery,

but none toward the central part. Plate II., Fig. 2. The

same was true in the kidney. In none of the sections were

carbon-laden leukocytes seen in the blood-vessels.

NECTURUS II.

About } c.c. of the carbon mixture was injected into

the abdominal cavity. Carbon-laden leukocytes were seen

circulating in the gills after the seventh day. The animal

was examined 100 days after injection. There was no free

carbon anywhere, a very few carbon-laden leukocytes were

found in the blood, while the abdominal fluid was black with

carbon-laden cells. Carbon-laden leukocytes were found

wandering into the tissues.

96 JOHN M. BERRY:

NECTURUS III. and IV. showed nothing different.

NECTURUS V.

About 3} c.c. of the carbon mixture was injected into the

jugular vein. The animal was examined the day after the

injection was made. The wandering leukocytes were present

in the tissues. Ingested leukocytes were present in the

abdominal fluid. There was no free carbon anywhere.

NECTURUS VI., which was left fourteen days, showed the

same thing.

NECTURUS VII. was injected in the abdominal cavity and

left twelve days. No free carbon was found and the wander-

ing into the tissues of carbon-laden leukocytes could be seen.

In the liver the ingested cells were present in the blood and

between the liver cells proper. The carbon was very

abundant along the periphery of one edge, while that of the

opposite edge was almost free. This is explained by the

fact that the edge which showed the abundance of carbon is

on the dorsal side of the liver, where the abdominal fluid

freely bathes it.

NECTURUS VIII. showed nothing different.

NECTURUS IX.

About } c.c. was injected into the jugular vein. Exam-

ination made six days later. Carbon-laden leukocytes were

found in the abdominal fluid and in the blood. No free car-

bon was found. The dorsal aorta was exposed and tied

cephalad of the point where the splenic arteries are given off.

A 6-10 per cent. chloral solution was then forced cephalad

into the aorta. By this means the blood-vessels of the

spleen and liver were washed out, but that this might be

more thorough the liquid was also forced in the opposite

direction through the portal vein. Picric alcohol was then

forced through to insure thorough fixation of the parts.

Sections were made of the liver and spleen. In the liver the

LEUKOCYTES IN AMPHIBIA AND MAMMALIA. 97

appearance was that there were carbon-laden leukocytes

outside the capillaries and also carbon in pigment cells.

(Plate I., Fig. 2.) In the spleen the carbon seemed to

have the same relation to the tissues as Miss Claypole

described.

NECTURUS X. was injected in the abdominal cavity and

left for 164 days. Carbon-laden leukocytes were found in

the abdominal fluid, but not in the blood. No further exam-

ination was made.

The results in regard to experiments on Wecturus, as can

be seen from the above, are similar to those of Miss Claypole

when the animals are kept alive for only a short time. When

carbon was injected into the abdominal cavity it made its

appearance after some days in the blood enclosed in leuko-

cytes, and when, on the other hand, the injection was made

into the jugular vein the carbon-laded leukocytes appeared

in the abdominal fluid. The apparent wandering out of the

carbon-laden cells in the lungs, intestinal tract and kidney

was found even in Wecturus V., which had been injected in

the jugular vein for only one day when examined. Transfer

of the carbon from the blood to the lymph had also taken

place in this short time since carbon-laden cells were found

in the abdominal fluid. It is interesting to note that in

Necturus 1., although carbon had not appeared in the blood,

it was found in the periphery of the liver. More will be said

in regard to this later. The liver and spleen are organs in

which the relation of the carbon to the tissues is very difficult

to make out. Miss Claypole found in the liver that the car-

bon was present only in leukocytes and that these were always

intravascular. Many of my sections would seem to show

that not only was carbon present in leukocytes which were

extravascular, but in one case (Vecturus IX.) the appearance

was that carbon was present inthe pigment cells. The fact

that in WMecturus I1., while but a very small amount of car-

bon could be found in the blood, yet a section of the liver

showed a comparatively large amount of carbon would seem

98 JOHN M. BERRY:

to show that some of the carbon present in the liver was

extravascular.

It is only when animals are examined that. have been left

for a considerable time after injection that conditions are met

with that do not correspond with Miss Claypole’s conclusion,

that the carbon-laden leukocytes would all wander from the

body. In Wecturus II., from the condition found in animals

examined only a short time after injection, one would expect

that all of the carbon, with the possible exception of that in

the spleen and liver, would be out of the body. The actual

fact was, however, that the greater part of the carbon was

still present. Why there should be such a large amount of

carbon still in the abdominal cavity, while there was such a

small amount in the blood, is a fact for which I can find no

explanation. A great quantity of carbon was also collected

under the peritoneum in the connective tissue of the abdominal

wall.

The same methods were employed for the experiments on

mammals as on Wecturus. The exact relationin the liver and

spleen was not attempted to be worked out. The results are

as follows :

Rat I., II. and III. injected with about 1.2 c.c. of carbon

mixture into the abdominal cavity and left two, seven and

fifty-nine days respectively. No free carbon was found in

either case. Essentially the same phenomena were found as

in Vecturus. In Rat II., while carbon was found in blood,

tissues and abdominal cavity, there was none in an abdominal

lymph gland. In Rat III., while much carbon was present

in the abdominal fluid, there was none in blood and but a

small amount in the tissues. In Rat III. the carbon had col-

lected in large quantities beneath the peritoneum.

Rat IV. was injected in the jugular vein. Carbon-laden

leukocytes were found in the abdominal and thoracic fluids

the next morning. Thecarbon-laden cells had also wandered

into the tissues somewhat.

LEUKOCYTES IN AMPHIBIA AND MAMMALIA. 99

RAT VY:

Animal was fed a mixture of cream and egg into which

carbon mixture had been stirred. The animal was examined

the next day. Portions of the stomach, small intestine,

cecum and large intestine were taken. Some preparations

were fixed in osmic acid to show the fat absorption, while

others were fixed in ordinary fixers and stained to show the

carbon. It was seen that fat absorption took place, but in

no section could I find any carbon within the tissue, but in

every case, and especially in the stomach, the appearance

was that some of the carbon was enclosed in leukocytes.

idee: Ve his. 2,

RAT VI.

Animal was placed ina glass jar and the air in the jar

filled with a fine suspension of lampblack by means of- an

insect powder spray. The animal was allowed to breathe

this for about three-quarters of an hour. The animal was

examined the next day. Sections were made only of the

lungs. Carbon was found in leukocytes, free in the alveoli

and also in the walls of the infundibula. Plate V., Fig. 1.

An interesting result of experiment is shown in Cat I.

In this case the injection was intended to be made into the

abdominal cavity, but the needle did not penetrate far enough

and the carbon was injected into the subcutaneous tissue.

The animal was examined afterthree days. A large quantity

of the carbon was found to be free along the inner surface of

the skin, but a large amount had been taken up by leukocytes

and carried away, following, in great part, connective tissue

bundles. Plate Il., Fig. 3.

DOG I.

Animal injected with about I c.c. into the abdominal

cavity. Examined after two days. Very little free carbon.

Carbon laden cells were present in the abdominal and thor-

acic cavities. No carbon was found in the blood, although

carbon was found in the lymph glands of the abdomen.

100 JOHN M. BERRY :

DOG II.

Animal injected with about 1.2 c.c. in the abdominal

cavity. Examined after fifteen days. No carbon-laden cells

were found in the blood or thoracic cavity, but these were

present in the abdominal cavity. There was no free carbon.

Carbon-laden cells were wandering into the tissues and were

found free on mucous surfaces. The abdominal lymph

glands contained comparatively little carbon. The carbon

was very abundant in the connective tissue of the abdominal

wall.

RABBIT I.

Injection made into a vein of the ear. Animal was left

fifteen days. No free carbon was found. No carbon-laden

cells were found in blood, but these were present in abdominal

and thoracic fluids.

From the results of the above experiments it will be seen

that essentially the same phenomena occur in the mammals

as in the Ampfhzbza. When the injection was made into the

abdominal cavity of a mammal the foreign particles were

quickly ingested by the leukocytes and in a short time these

leukocytes made their appearance in the blood and in the

tissues of the body. When the injection was made into a

vein the carbon-laden cells appeared in the abdominal cavity.

This shows that as in Ampfzbza transfer takes place from the

lymph to the blood and from the blood to the lymph. The

wandering out upon mucous surfaces of carbon-laden cells is

found to be common to both Amphibia and Mammalia. In

the WVecturus it was found that the carbon was, to all appear-

ances, outside of the blood-vessels in the liver. This seems

to be true also with the mammals, for when no carbon could

be found in the blood, sections of the liver showed the pres-

ence of much carbon. Carbon was always found in the

spleen, but no attempt was made to work out its exact rela-

tion to the organ; it was noted, however, that there was

never any carbon within the malpighian corpuscles.

LEUKOCYTES IN AMPHIBIA. AND MAMMALIA. IOI

In mammals as in Amphzbza, when the animal is left alive

for some time after the injection it is found that a large

amount of carbon is still in the body. In mammals the col-

lection of carbon under serous membranes and in connective

tissue is especially marked. (Plate II., Fig. 1.)

Experiments were performed on mammals that showed

that the action of the leukocytes toward foreign matter is

even more complicated than was found in previous experi-

ments on WVecturus. The leukocytes act both ways, for not

only do they remove foreign matter from the body to a cer-

tain extent, but they also bring it into the body from the

lungs and possibly the intestinal tract.

Only one experiment was performed to determine whether

foreign matter could enter the body through the alimentary

canal. The result of the experiment was that while no car-

bon was found in the tissues of the intestine, yet cells con-

taining carbon were found in the lumen of the canal.

Whether or not these leukocytes would again enter the tissue

of the enteron can only be determined by further experimen-

tation.

On Rat VI. an experiment was performed to throw some

light on a point over which there have been numerous dis-

cussions, viz: Whether foreign matter enters the body

through the lungs, and if so, how this takes place. Dr.

Arnold, who has done the most work in this line, came to

the conclusion that the lymph glands act as filters. Others

believe that the carbon enters the lymph stream free through

preformed paths. The trouble with all investigations was in

the manner of experiment. Arnold in many cases caused

the inhalation of so much foreign matter that the animal

died, and other experimenters even introduced the foreign

matter into the lungs suspended in a liquid; it is not to be

wondered at that pathological phenomena would result.

While I have performed only one experiment along this line

and consequently cannot hope to solve the problem, yet

carrying out the experiment as nearly under normal condi-

102 JOHN’ M. BERRY:

tions as I could and getting into the lungs comparatively

only a small amount of carbon, I feel that what took place

was physiologically true. The results show that carbon

enters the tissue of the lung. No carbon enters the tissue

that is not enclosed in cells. I could determine whether, as

Arnold said, the lymph glands acted as filters only by further

experiment ; but they certainly do not in the elimination of

carbon-laden leukocytes from the abdominal cavity and I do

not see why they should here.

The experiment on Rabbit I. shows that transfer of car-

bon from the blood to the lymph takes place. This is com-

parable with the results found in WMecturus.

When now a comparison is made between Amphzdbza and

Mammalia it is seen that in the main the phenomena are the

same. In neither case was free carbon found anywhere in

the tissues. The fact that so many experimenters report

free carbon may be due to the collection of carbon at the

connective tissue nodes. And it is very possible that the

appearance of free carbon is given by the tearing of the

knife in making the sections.

In Necturus 1., before carbon-laden leukocytes had made

their appearance in the blood, sections of the liver and kid-

ney showed carbon at the periphery. This shows that carbon-

laden leukocytes can leave the abdominal cavity without first

entering the blood. In mammals it was found that when the

tissues around the abdominal cavity as well as the blood con-

tained great quantities of carbon the lymph glands were

comparatively free. This shows that the carbon laden leuko-

cytes can leave the abdominal cavity without first entering

the lymph. The results in both Amphzdia and mammals

show, therefore, that the carbon does not wholly enter the

blood and, on the other hand, does not wholly enter the

lymph stream; but when leaving the abdominal cavity

enclosed in leukocytes, the leukocytes wander where they

will. It would further seem that those escaping from the

body do so only by chance, for if the object of the leukocyte

LEUKOCYTES IN AMPHIBIA AND MAMMALIA. 103

was to rid the body of foreign matter why should it carry

foreign matter from the lungs into the body? In both

Amphibia and Mammalia more carbon is found in the spleen

following intravenous injection than after abdominal injec-

tion. This would seem to show that the carbon that is in

the spleen comes through the blood and not the lymph. In

the liver, however, carbon appears in the periphery before it

is found in the blood (Wecturus I.). This difference may be

due to the greater density of the capsule of the spleen.

The finding of carbon-laden leukocytes in the abdominal fluid

in the case of Necturus II., three months, and in the case of

Rat III., two months after injection, is not easy to explain.

It is hard to see why they should be there in any case; but

since they were there their presence might indicate that the

leukocytes lived three months at least. It may be, however,

that before wandering out, the leukocyte has degenerated and

the carbon has been taken up by fresh leukocytes.

As to what will be the ultimate fate of the carbon can be

told only by continued experimentation and extended time.

As far as my experiments have carried the carbon has been

always found in leukocytes with the exception of the splenic

pulp cells and possibly the pigment cells of the liver. How

the carbon finds its way into these is a question yet to be

solved. The changing of a leukocyte to a fixed cell is a

phenomenon that has never been seen and for which there is

no proof. I found nothing that would indicate this in any of

my sections. I simply noted the tendency for the carbon to

collect under serous membrane, but can offer no explanation

for it.

GENERAL SUMMARY.

I. The phenomena in Amphtbta and Mammalia are

essentially the same.

2. No free carbon in tissues.

3. Carbon passes from lymph to blood.

4. Carbon is transferred from blood to lymph.

104 JOHN M. BERRY:

5. There is no special road by which the carbon leaves

the abdomen.

6. Foreign matter escapes from the body through lungs,

intestinal tract, kidney and skin.

7. Leukocytes that wander out do so by chance.

8. The situation of the carbon was the same as that found

by Miss Claypole with the exception of the liver where the

carbon is outside of the blood-vessels in my experiments.

9g. Foreign matter may enter the body through the lungs

and possibly through the intestines.

10. The carbon-laden cells tend to collect under serous

membrane.

METHODS.

In addition to the general methods already spoken of, it

may be well to give some of the details that were used in

preparing the specimens for examination. For fixing and

hardening the tissues the picric-alcohol method, as used by

Prof. Gage, was found to be the simplest and most effective

when only the general structure of a part was desired. The

whole animal could be put into this fixing agent, but the best

results were obtained when small pieces of the tissue to be

examined were cut out and fixed. It was found advisable in

either case to change the liquid at least once. When the

relations of cells and minute structures were to be worked out

a saturated normal salt solution of mercuric chloride, to which

one per cent. of acetic acid was added, was found to be the

best fixer. Care must be taken in the use of this to wash -

out all of the mercuric chloride or there will be black crystals.

in the tissues.

Tissues were sectioned by both the collodion and paraffim

methods. The collodion method employed was that used by

Prof. Gage. Most of the sections were made by the paraffim

method and it was easier to make serial sections.

A large amount of pigment was found in the tissues of

Necturus. Toremove this the sections, when cut and fastened

LEUKOCYTES IN AMPHIBIA AND MAMMALIA. 105

to the slide, were placed ina jar of hydrogen dioxide (10

Vol. or 2 per cent. solution), the pigment became light

yellow in a few hours. The process was hastened by placing

in sunlight. This could not be done when the sections were

cut in collodion and fastened to the slide by ether-alcohol

since the hydrogen dioxide seemed to act on the collodion

and loosen it from the slide. Very little trouble was found

when the sections were cut in paraffin and fastened to the

slide with albumen fixative.

A stain of hematoxylin and Van Gieson’s picro-fuchsin

was found to give the best results. The sections were first

stained with hematoxylin and then with the picro-fuchsin, the

formula for which is :

I per cent. aqueous solution acid-fuchsin, § c.c.

Saturated aqueous solution picric acid, 100 c.c.

The specimen should be mounted in acid balsam after

using this stain, 7. ¢., in balsam which has not been neutralised.

106 LEUKOCYTES IN AMPHIBIA AND MAMMALIA,

BIBLIOGRAPHY.

No attempt has been made to give a complete bibliography

of the articles written that apply to this subject. A _ bibli-

ography of 264 works can be found in Arnold’s ‘‘ Unter-

suchungen iiber Staubinhalation und Staubmetastase.” Sev-

eral articles not mentioned by Arnold can be found in Miss

Claypole’s bibliography.

ARNOLD, J.: Untersuchungen iiber Staubinhalation und Staubmetastase.

ARNOLD, J.: Altes und neues iiber Wanderzellen, insbesondere deren Her-

kunft und Umwandlungen. Virchow’'s Archiv., Bd. C., 1893.

Ciaypo_e, EpitH J.: An Investigation of the Blood of Necturus and Cryfio-

branchus. Proc. Am. Mic. Soc., Vol. XV., 1893.

CounciLman, M.: A Contribution to the Study of Inflammation as Illustrated

by Keratitis. Journal Physiol., Vol. III., 18S0

Gace, S. H.: Improvements in Oil Sectioning with Collodion. Proc. Am.

Mic. Soc., Vol. XVII., 1895.

Gace, S. H.: Picric and Chromic Acid for the Rapid Preparation of Tissues

for Classes in Histology. Proc. Am. Soc. of Micros., 1890.

Harpy, W. B. and Wesprook, F. F.: The Wandering Cells of the Alimen-

tary Canal. Jour. of Physiol., Vol. XVIII, 1895.

Hertwic, O.: TheCell. Trans. by Campbell. 1895.

HEIDENHAIN, R.: Beitrage zur Histologie und Physiologie der Diinndarm-

schleimhaut. Archiv. f. gesammte Pysiol., Vol., XLIII., Supplementheft,

1888.

Koutuack, A. A.and Harpy, W. B.: The Morphology and Distribution of

the Wandering Cells of Mammals. Jour. Physiol., Vol. XVII., 1894.

Kincssury, B. F.: The Histological Structure of the Enteron of Mecturus

maculatus. Proc. Am. Mic. Soc., 1894.

MetcHNikorF: Lectures on Inflammation. Trans. by Starling, 1893.

RurrFer, A.: On the Phagocytes of the Alimentary Canal. Jour. of Mic.

Soc., Vol. XXX., 1889.

SENN: Surgical Bacteriology.

SIEBEL: Ueber das Schicksal von Fremdkérpern in der Blutbahn. Virchow’s

Archiv., Vol. CIV., 1886.

SuLzErR, M.: Ueber den Durchtritt corpusculéiren Elemente durch das

Zwerchfell. Virchow Archiv., Vol. XLIII., 1896.

ZIEGLER: General Pathology, 1895.

108 LEUKOCYTES IN AMPHIBIA AND MAMMALIA,

PLATE I.

Fig. 1. Transection of small intestine of Mecturus VI., drawn with

the camera lucida from a single field of the microscope; the carbon-laden

cells can be seen within the blood-vessel and wandering out through the tissues

toward the lumen.

(a) epithelial cells.

(dz) circular muscular coat.

(e) connective tissues.

(7) blood-vessel.

(@) carbon-laden leukocytes.

Fig. 2. Section of the liver of Vecturus IX.

(a) liver cell.

(5) pigment cell of liver containing granules of carbon.

IIO LEUKOCYTES IN AMPHIBIA AND MAMMALIA.

PLATE II.

Fig, 1. Section of abdominal wall of Rat III.

(a) muscle bundles.

(6) peritoneum.

Fig. 2. Section of liver of Mecturus I.

(a) liver cell.

(6) pigment cell.

(dz) bile capillary.

(e) carbon-laden leukocytes.

Fig. 3. Section through the skin of Cat I.

(a) epidermis.

(6) section of hair follicle.

(@) adipose tissue.

(e) blood-vessel.

(7) connective tissue.

(g) carbon-laden leukocytes. Note the free carbon in the connec-

tive tissues beneath the adipose tissue.

112 LEUKOCYTES IN AMPHIBIA AND MAMMALIA.

PLATE Ill.

Fig. 1. Section of stomach of Dog II.

follicle.

connective tissue.

gland.

carbon-laden leukocytes wandering out.

Fig. 2. Section of lung of Dog II.

infundibula.

walls of infundibula.

blood-vessel.

carbon-laden leukocyte.

PLATE III.

ON J

Oaligac* SS

SSIS 28

é Wet SIFY

ASS ed Mf a S10 » 4 ‘ Yay at

3 >, ‘ Y )\e 4 AL ety

VOSS — 2747 aah

ras _wZ% (Sb-9%

Ay Se AG VARS

ee 58 7 Ves

REA eS PEANSS

NOP agg 8 Boe =

a WE we een g=

Sa tae 9 Do. Gare

SOA ar TC We SA td

a ee para”, SoeeoS=

SS ff 1D 090 ox 94 era

eer ERS Og Leos

po et 9 ass oe cene

J re Co 627°

Sri g 237 4 4 of

fe 15 049 30 Ge

eS) e _..a gat yyet-- d

ae 24g 3 3b 9 Cane j

¢ y. lo

Ve MA A f By rs 9%}

At ae aS VA ady,

OM oy! ' 1875 Oo” LZ

pitts ag CEH = b

PP Ker 7 Se ial

oe Le SOF ahi

Lr), LPB 2!

SU AL ase, ae -

Wheornpet (ELS aa Ag

A Nig EST gh feo,

pb NEES Watney Bt

W098 FISH 583 PISS Bee

AE cd Ake GEL > nw 224 = fF

JOUER Oy! ete ee Zale

Ve pe aA AT oe irene ng

gree Ze 11 MyAbl a ot AA See

eI y fe ee fy 4 EU 6

Ss! aa Ue ES aN

B44 @ Pi ae oN

29, by amg ae ay

Ly any Re ee X38. &

elite A anaes eu

- v

Bar’ ta %,

ED re :

we ‘

—_ <—-— xo

PP eT ui ee

VD aes

-—— 12g 44,9 a SSS

a Z ps4 ati Se

2 2 2a Po.) SS SSE

Py eee SY) es Oates

SF ate TE | seeees ae, el

Ss)

II4 LEUKOCYTES IN AMPHIBIA AND MAMMALIA.

PLATE IV.

Fig. 1. Section through the diaphragm of Dog II.

(a) blood-vessel.

(0) connective tissue.

(2) adipose tissue.

(e) carbon-laden leukocytes.

(7) the abdominal surface.

Fig. 2. Portion of the urinary tubule from kidney of Dog. I.

(a) lumen of tubule.

(6) cell of wall of tubule.

(€) carbon-laden leukocyte in lumen of tubule.

PLATE IV.

Ao eu §

Wes

116 LEUKOCYTES IN AMPHIBIA AND MAMMALIA.

PLATE: V.

Fig. 1. Section of lung of Rat VI.

(a)

(3}

(¢)

infundibula.

section of bronchiole.

walls of infundibula.

carbon-laden leukocytes.

Fig 2. Section through the villi from intestine of Rat V.

(a)

(d)

(c)

(@)

(e)

epithelial cells.

connective tissue.

goblet cell.

carbon-laden leukocytes.

uningested carbon free in lumen of intestine.

| bon

es ate)

: oxy el lahat ot da o Wallin

C Ae Se Se SB

‘fe

Sao a, oes

a ines

PLATE V.

AY ey bl kaa

NP SoS a> Ne =

: oF Pei yh en ag

z 4 SS, 2 _o- Lew >

eh Sa eS =

“

A COMPARATIVE STUDY OF HAIR FOR THE MEDICO-

LEGAL EXPERT.

WILLIAM GEORGE REYNOLDS, M.D., WatTeERTOwN, CONN.

In the examination of hair and fibers presented to the

medico-legal expert, three questions naturally arise in mind,

demanding intelligent answer: Is the object hair from a

human body? Is it like hair from a human body? And, if

so, ought that fact to influence his mind to believe it to be

human hair ?

Each hair presents two principal divisions, the portion

embedded within the integument or root, which terminates

at its lower extremity in a bulbous expansion for retention in

the hair follicle, and the part which projects beyond the sur-

face of the integument, called the shaft. To the medico-

legal examiner, the root is of but little importance, signify-

ing by its continuity with the shaft that the hair had fallen

because of constitutional disease, alopecia, or had been

violently removed. The shaft, however, presents naked eye

and microscopic characteristics that aid materially in its

determination. The former are shape, length and color, the

latter with the histological divisions of the shaft are form,

diameter, color, the histological divisions being the cuticle

or epithelial covering ; the cortical substance, consisting of

elongated elements so intimately united as to be indistin-

guishable under ordinary circumstances, and the medulla or

pith, occupying the central tract of the shaft.

On all fur-bearing animals there are two varieties of hair,

known to the furriers as over hair and under hair. The over

hairs are coarser, fewer and harsher, extending beyond or of

118 WILLIAM GEORGE REYNOLDS :

equal length with the under hairs, giving the peculiar beauty

and richness that marks the pelt of the Russian sable, J/us-

tela ztbellina. The under hairs are softer, finer and more

abundant, qualities that render the seal skin, Cal/orhinus

ursinus, of such value.and elegance. Aside from the black-

skinned races, whose hair is peculiarly kinked and curly, the

hair of man’s head and face is straight, while that from the

axilla, chest, arms, legs and genitalia is irregularly bent and

sinuous.

The length of the hair of animals rarely exceeds six to

eight inches, except that of the South American monkey,

Colobus vellerosus, of the Angora, Astrakhan, Ovws aries,

and other wools, and of the equine and asinine species of

animals, it is not above three or four inches in length ;. while

from many creatures, ¢. g., the common horse, rat, Jus rat-

tus; Mouse, Mus musculus, and the red squirrel, Sczurus

hudsonius, it is less than an inch. The hair of the mane

and tail of the horse, Aguas caballus, is commonly from

eighteen to twenty-four inches long, the estimated length of

the hair from woman’s head. Exceptionally, the latter and

the beard of man that has never been shorn reaches the great

length of seventy inches. The average length of the hair

of man’s head, though short, is indeterminable for obvious

reasons, hence shortness cannot exclude human hair, though

length may exclude animal hair.

The range of natural color of hair is very limited, but the

peculiarity of its arrangement in individual shafts is, in

several instances, distinctive. A parti-colored shaft is not

found in human hair, but does appear on the red squirrel,

Sciurus hudsonius, where there are alternate sections of

tawn and black from root to tip; on the gray squirrel,

Sciurus Carolinensis, black and white; on the common rat,’

Mus rattus, black and white; onthe rabbit, Lepus sylvaticus,

yellow, black and white; on the domestic cat, commonly

called tortoise shell, Fe/és domestica, black, yellow and white,

gray and white; on the guinea pig, Cavia cobaya, yellow or

A COMPARATIVE STUDY OF HAIR. 119

tawn and white and on the body of the Scotch terrier, Canzs

familiaris, tawn and black. Deeply pigmented shafts,

whether from man or other creature, are lacking in color at

the root end. Black and dark brown hair characterise many

races; that of the Indian, Negro and Celestial is jet black.

Blonde and golden hair is less prevalent and red appears in

individuals and families scattered among the lighter haired

peoples. Upon the same body and upon the same head

hairs very different in color are frequently found. So-called

golden and auburn hairs are made up of blonde and red hairs,

mingled in varying proportions. The beard and body hairs

of man are generally lighter than those of the head. The

color of hair dyed with lead, bismuth or silver salts may be

readily removed by means of 20 per cent. nitric acid. Such

color may be detected by subjecting to microscopic examina-

tion, where it is seen to be superficial, with particles of pigment

adhering to the surface of the shaft and occasional spots

present unstained. ‘‘Under the microscope dyed hair

exhibits a far greater degree of regularity of color than is

found in nature.”

The form of the hair shafts of human and other hairs is

very generally round. Exceptions to this are the hair of the

coney, Hyrax syriacus, the shafts of which are flat and that

of the Negro, which is oval, determined on cross section.

The downy under hair of furs, while often woolly and sinuous

in outline, are round.

The form of terminations of the shaft indicate in a meas-

ure its source. Long tapering points are not present in

human body hair. The hair of nearly all common furs of

unshorn domestic animals have sharp points. The fine hair

from the seal, Cadlorhinus ursinus ; coney, Hyrax syrtacus ;

beaver, Castor Canadensis ; and otter, Lutra Canadensts, are

frequently blunt from having been sheared. The hairs from

the heads of men are blunt, either sharply cut off or slightly

worn ; those from the eyebrows, eyelashes and some body hairs

are fine-pointed, those from the eyelid and brow terminating

120 WILLIAM GEORGE REYNOLDS :

as acone. The hairs from the head of a woman may or may

not be pointed sharply. Often it is torn, frayed and broken

from frequent brushing and combing. Hairs that have been

removed violently from the head may be crushed, frayed,

with a portion of the epithelial covering removed, or be in

continuity with the root and bulbous portion. When so torn:

out they may be accompanied by blood in small quantities

and epidermic scales.

It is a quality of all over hairs that their greatest diameter

is in that part of the shaft projecting beyond the under hair.

From this enlargement the shafts taper to a point, the tip of

the shaft, and toward the base or root end, where it frequently

is less than one-fifth of the diameter of midshaft. Under

hair has alternate constrictions and enlargements in the

diameter of the shaft, from root to tip. Hair from the head

of a woman is similarly characterised and there may be as

many as fourteen demonstrable changes in diameter in a single

shaft. The shaft does not progressively diminish in diameter

from root to tip, but may be apparently uniform throughout

the major part of its course. In addition to variations in

individual shafts, hairs from the same body, from the same

head may differ much in the diameter of their shafts. The

locally growing body hairs are coarser than the hair

from the head. The hair from the mane of a horse,

Equus caballus, may be finer than that from the head of a

Chinaman and six inches from the ends of long mane hairs

may be as fine as hair from a woman’s head. There

is nothing in the diameter of the hair from the South

American monkey to distinguish it from black human hair.

This, together with its jet black color and length, makes it

difficult to isolate from human hair. The coarsest human

hairs are dark in color, the finest are the blonde and golden

hairs.

The hair cuticle is composed of a single layer of imbri-

cated scales, which envelope the entire surface of the shaft.

Owing to their peculiar shingled arrangement they are

A COMPARATIVE STUDY OF HAIR. P2Y

frequently imperceptible, except at the margin, where they

appear as delicate serrations, such serrations distinguishing

the shafts of cat’s hair, Felis domestica ; seal, Callorhinus

ursinus ; and coney, Hyrax syriacus. The under hairs of

all furs are distinctly marked inthis manner. Inthe raccoon,

Procyon lotor; coney, Hyrax syriacus ; Russian sable, Mustela

gtbellina; marten, Mustela Americana, mink, Putorius vison;

rat, Mus rattus; otter, Lutra Canadensis; beaver, Castor

Canadensis; chinchilla, Chinchilla lanigera ; and cat, Felis

domestica, the scales apparently flare out from the shaft at

their distal ends and vary in length with the diameter of the

shaft ; where it is broad they are shorter and more closely

set, where narrow, they are longer and may be several times

longer than the diameter of the shaft. In wool from sheep,

Ovis artes, with its varieties, Astrakhan and Shiraz, and in

long silky hair from the Angora goat, Capra hircus, variety.

Angorensis, the scales are visible, not only as serrations, but

also upon the surface of the shaft. Upon human white hair

and the white hair of the horse very delicate transverse

striations may be seen which correspond to the imbrications

of the scales. These may be more readily demonstrated by

staining lightly with Gabbet’s methylene blue. The hair

shaft from the Chinese goat, Capra hircus, is marked by a

spiral arrangement of its epithelial covering. The serrations

of the coarse overhairs are more distinct at the base than in

any other portion of the shaft, and generally where the shaft

is widest there the scales are less distinct. A rootless and

pointless hair indicates by the arrangement of its scales the

source of growth, for the free end of the imbrication points

toward the free end of the shaft. In many hair shafts there

appears to be a definite relation between the scales of the

cuticle and the pith cells of the medulla. This is best seen

in the hair shaft (fine) of the red fox, Vulpes fulvus. The

epithelial scales on the hair shafts of the horse, Eguus caéal-

lus ; cow, Bos domestica; dog, Cants familiaris ; pig, Sus

scrofa, and man are fine, closely set to the shaft and have

122 J WILLIAM GEORGE REYNOLDS ;

free distal ends that appear sharp at the margins. Ordinarily,

the cuticle is not pigmented, but in the black human hairs

and hairs from the cow, Los domestica ; horse, Equus cabal-

lus ; South American monkey, Colobus vellerosus ; and dog,

Canis familiarts, it may be intensely black. The cuticle

may be removed from the shaft by treating with strong caus-

tic potash or sulphuric acid. When so removed it may

appear as a homogeneous membrane.

The cortical substance of the shaft is singularly scant in

the hair of the rat, W/us rattus ; red, gray and black squirrel,

Scturus hudsontus, Carclinensis, and niger ; rabbit, Lepus

cuntculus and Lepus sylvaticus, and cat, Felzs domestica,

more abundant in that of the dog, Cauzs famitliarzs ; horse,

Equus caballus ; cow, Bos ; raccoon, Procyon lotor ; pig, Sus

scrofa ; otter, Lutra Canadensis ; beaver, Castor Canadensis ;

skunk, Mephitis mephiticus ; musk rat, Fiber stbethicus ;

guinea pig, Cavia cobaya ; mink, Mustela vison ; opossum,

Didelphys Virginiana ; andconey, Hyrax syriacus, and makes

up the greater portion of the shaft of the seal, Callorhinus

ursinus ; South American monkey, Colobus vellerosus ; lamb,

Ovis aries ; goat, Capra hircus variety Angorensis, and of

many of the under hairs of the otter, badger, skunk and coney.

The pigment of colored hairs lies within the cortical substance.

It is generally present in minute granules that have a linear

arrangement parallel to the axis of the shaft and apparently

deposited between the elements of the cortical substance,

and as diffuse pigment. Both forms are equally distributed

between the cuticle and medulla in some hairs, especially

human, dog, horse and many others, but in the squirrel,

cat, rat, mouse, rabbit, hairs having wide and complex

central piths, it appears to be deposited among the cells of

the medulla, the cortical substance being clear. In many of

the darker shades of hair, the pigment is so dense as to

obscure the structure of the shaft. This may be removed by

treating with hydrogen peroxide or strong nitric acid, the

shafts being immersed in the former for a number of hours,

A COMPARATIVE STUDY OF HAIR. 123

in the latter, but a few minutes or seconds. Hair that is

turning gray may have isolated granules of pigment present

in the cortical substance. In blonde hair the granular pig-

ment is lacking, as it is also from perfectly white hair.

Granular pigment is best seen in red hair (human) and diffuse

pigment in blonde.

In the darkest shafts there is a diminution of color toward

the root end. The structure of the cortical substance may

be demonstrated by macerating in concentrated sulphuric

acid. White hair taken from the bodies of animals are milky

white, excepting the under hair from the wolf, Canzs occiden-

talis; the white horse, Equus caballus, whichis pearly white,

as is also human hair.

The cellular structure of the medulla is, in many instances,

the most striking characteristic of the shaft. In the fine

hair of the seal, Callorhinus ursinus; otter, Lutra Canaden-

sis; lamb, Ovts aries; goat, Capra hircus, and the hairs of

children it is absent or at least undemonstrable. In perfect

hairs it does not extend the entire length of the shaft, being

absent from the root end and tip, and in many appearing as

a narrow line that frequently is broken. The diameter of the

pith in its relation to the diameter of the entire shaft is con-

stant, the dimensions of the medulla elements changing with

the dimensions of the shaft, for where the shaft is broad the

elements are broad and shorter, where the shaft is narrow

they are narrow and longer. This is clearly demonstrated

in allunder hairs. In the hair of the rat, Wus rattus; mouse,

Mus musculus; red, gray and black squirrel, Sczurus hudson-

zus, Scturus Carolinensts and Sciurus niger, red, gray and

white Arctic fox, Vulpes fulvus, Vulpes Virginianus, Vulpes

lagopus, wild and pet rabbit, Lepus sylvaticus and Lepus

cuniculus, and domestic cat, Felis domestica, the cells are

disposed to appear much like the kernels of corn upon the

cob. When the shafts are very coarse, as in the cat, this

arrangement is not preserved as in the under hair, but there

appears to have been a destruction of the central cells. Where

124 WILLIAM GEORGE REYNOLDS :

the under hair has a medulla, it presents as a string of spheri-

cal or cylindrical beads. In other portions of the same shaft

it may appear as a series of minute discs in close apposition.

These variations are found in all but human hairs. In the

over hair of the dog, horse, cow and many others, the cells are

larger, extending across the entire width of the medulla, which

occupies a third or more of the diameter of the shaft. In

human hair the cells of the medulla are cuboidal or irregu-

larly spherical, they are not generally continuous through the

shaft, but clusters of such cells, which look not unlike a tan-

gential section of the ray cells present in pine wood. Where

the central cells have been destroyed and the medulla has

been converted into a central canal or air space, in light

hairs it appears as an irregular black line that rarely occupies

more than one-fifth to one-third of the diameter of the shaft.

In darker hair it is present often as a narrow line of light.

Fibers that may appear as hair to the naked eye are cot-

ton, linen, silk and wool (here considered as a fiber because

worn for domestic uses). Cotton fibers, under the micro-

scope, appear as flattened bands that are twisted and sharply

bent; linen fibers are rectilinear, have nodes or jointed

markings at irregular distances and taper rapidly to a point ;

silk is cylindrical, free from all markings and refracts light

powerfully ; wool has peculiar, readily distinguishable surface

markings corresponding to the imbrications of the shaft.

In distinction from human hair, then, that of the rat,

Mus rattus ; mouse, Mus musculus; squirrel, Scturus hudson-

tus, Carolinensis and niger; fox, Vulpes fulvus, Vulpes

Virginianus and Vulpes lagopus, and cat, Felis domestica,

has a parti-colored shaft and a wide medulla with a fenestrated

structure and exceedingly narrow cortical substance; that

from the horse, Eguus caballus; cow, Bos; dog, Cants familt-

aris; raccoon, Procyon lotor; skunk, Mephitts mephiticus;

beaver, Castor Canadensis, otter, Lutra Canadensis; guinea

pig, Cavia cobaya; mink, Mustela vison; musk rat, Frber

stbethicus; pig, Sus scrofa; chinchilla, Chinchilla lanigera;

A COMPARATIVE STUDY OF HAIR. 125

opossum, Didelphys Virginiana; marten, MWustela Americana;

Russian sable, Wustela zibellina, differs by the character of the

medulla, its large cells and width compared to that of the

shaft ; that from the lamb, with its varieties, Astrakhan and

Shiraz, and the goat, Chinese and Angora, by the absence of

a medulla and its characteristically clear and distinct cortical

cells; that of the seal by the distinct laminate shape of its

scales and lack of a medulla, and from the hair of the coney,

Hyrax syriacus, by its flattened shaft. Some human hairs

differ imperceptibly from that of the South American monkey,

Colobus vellerosus. If a section of hair or hairs be presented,

the differences noted above between human and other hairs

may suffice to distinguish it, but exceptionally white hair

from the mane of a horse cannot be differentiated from that

of the human head, presenting the same homogeneous corti-

cal substance, narrow medullary canal and delicate transverse

surface markings. The hairs of the cocker spaniel and skye

terrier have been affirmed to be like human hair. My experi-

ence does not corroborate that observation, the medulla

being much wider, more regular and made up of larger cells

than are present in humanhair. In conclusion, then, it may

be stated in answer to the questions already given: a hair

whose origin is unknown ought not to be positively declared

human, though the probabilities be very strong in evidence

of that fact. Hairs may appear similar in structure to some

human hair, but though a hair be similar to or like a human

hair, that fact does not necessarily justify the belief that it is

human hair.

126

Fig.

Lani

eee ere aie fons Tate Ge Ae

10.

A COMPARATIVE STUDY OF HAIR.

PLATE “1.

Hair from a coney, Hyrax syriacus.

Hair from a cat, Felzs domestica.

Hair from a white horse, Equus caballus.

Hair from a gray rat, Mus rattus.

Hair from a Chinese goat, Capra hircus.

Hair from a seal, Callorhinus ursinus.

Hair from an opossum, Didelphys Virginiana.

Hair from a pig, Sus scrofa.

Hair from an otter, Lutra Canadensis.

Hair from a skunk, Mephitzs mephiticus.

Hair from a musk rat, Azber zibethicus.

Hair from a ‘nink, A/ustela vison.

Hair from a raccoon, Procyon lotor.

PLATE I.

Pe SPE pr oe Sasa SSS SSS SSS

a ——~

DEAD UD DH avETECHDONEOECH ACH EFANNT FeCoODCOONGCEC EE r>H NERS CrOCOORDOOET EM OOOHEN=

manent LST

ee I. eas HYP

—SS ee See

128

Fig

Fig.

Fig. 9.

Fig. Io.

A COMPARATIVE STUDY OF HAIR:

PLATE II.

Hair from a cow, Bos domestica.

Hair from a rabbit, Zepus sylvaticus.

Hair from a dog, cocker spaniel, canzs familiaris.

Hair from a South American monkey, Colobus vellerosus.

Hair from a man, Homo sapiens.

Hair from a man, //omo safiens.

Hair from a man, Homo sapiens.

Cotton fibers.

Silk fibers.

Linen fibers.

Lamb’s wool, Ovzs artes.

ey ltrt,

: hn | Le eat

fee Se an ‘ : dh ae Be Lay cow Mae aa ’

Obra “i ,, » ** iS

oe ee Pd Sarsgh os fiat ey Let 6 eee pear woe , P

/ ; : ~ 7 5

Sy Ree ht ue * ee dere) rf F, / Ts il a

A’STUDY OF THE ORGANS: OF TASTE,

A. E. LOVELAND, M. A., M. D., New Haven, Conn.

Introduction.

The small goblet-like bodies found in the superficial and

lateral area of the papillae distributed over the tongue, and

sometimes upon the epiglottis, anterior pillar of the fauces

and uvula, have long been recognised as the organs of taste,

and are uniformly called taste-buds from this peculiar bud-

like form. When they were first pointed out as the end

organs of taste is uncertain, but Waller3, in 1849, seems first

to have written upon their minute structure. Weber’, 1847,

and Valentin’, 1848, were earlier investigators upon the

organs, but they performed only physiological tests, the

former proving that taste sensation is greatest when the excit-

ing substance is at the temperature of. the body, and the

latter likewise demonstrating that the excitement of the taste

nerves depends on the concentration and not amount of solu-

tion applied. Since these investigators, a long line of obser-

vations have shown the general character of the organs to be

as follows: The taste-bud is formed by cells lying with their

long axis corresponding to the long axis of the bud, and

arranged in the shape of a bulb or bud, the nerve fibers pene-

trating within and between the cells, or enveloping the bud

without. The cells themselves are composed of two varieties,

the fusiform or sensory cells, and the flat, sustentacular or sup-

porting cells. The buds usually lie upon the sides and bases

of the papille circumvallate, fungiform, or filiform ; or, where

such an organ exists, upon the papille foliate, for example,

in the rabbit. These so-called sensory cells were early seen

to possess processes extending in either direction from the

body of the cell, the peripheral one reaching to the gustatory

pore or vertex of the taste-bud, and the central one being early

supposed to become connected with the nerve of supply.

130 A. E. LOVELAND :

The end organs of the body forming the organs of special

sense,—sight, hearing, taste, touch and smell,—have been

shown by Retzius to form two classes of organs with respect to

their nerve terminations. Eachsense organ may be considered

as essentially constructed of anerve cell with two processes, one

making its way centrally to cluster around other nerve cells or

their processes, and the other terminating peripherally. In

the organ of smell the peripheral process is very short, and is

directly irritated by foreign particles, being joined directly to

the sensory cell of the olfactory mucous membrane. The

organ of smell is then readily seen to belong to one class,

while the auditory organ and organ of touch belong to the

other class, where the nerve cell is found in the ganglion of

the posterior spinal nerve-root, and the peripheral process, if

very long, escapes in fine fibrilli among the epithelial cells

forming the organ, and is acted on indirectly through the

modified epithelium around which it clusters. The organs of

taste were until recently referred by all authors to the first

class, where the nerve was in direct continuity with the peri-

pheral cell, which was thus essentially a nerve cell.

Recent investigators, mainly Retziuss*, Von Lenhossék®,

Arnstein®s, and Jacques™, all writing since 1892, have denied

this and striven to show that these organs belong properly to

the same class as the auditory and touch organs, and thus that

the nerves are nowhere in direct continuation with the cells

of the bulb. Tuckerman‘, on the contrary, working a little

earlier on the development of these organs, claims to have

seen the sensory cells in direct connection with the nerves

and, indeed, points out that the development indicates also a

nervous origin for these cells themselves.

It was attracted by these variances in opinion, also because

the recent observations leading to such opposite results had

_been done by foreign investigators, and having an unusual

opportunity to get material for the study of these organs in

the fetus, that I undertook investigations upon the subject of

the development of the organs, and also their nervous rela-

ASS LUDDY “OK SEE (ORGANS OF VASE, B31

tions. After a brief resumé, therefore, of what has been done

both upon the physiology as well as anatomy of these organs,

I will give an account of my own methods and results.

PHYSIOLOGY OF THE ORGANS OF TASTE.

Historical Sketch.”

Camerer** and Wilczynsky3+ have been able to prove

satisfactorily that only parts of the tongue provided with taste-

buds can give taste sensations, and according to Shore” a

considerable area in the mid-dorsum of the tongue is, there-

fore, devoid of all taste-sensibility. '

Oehrwells gives some valuable results bearing upon this

point. He examined 125 separate papille (of the fusiform

type) scattered over the tongue, with succinic acid, quinine

and sugar.

Twenty-seven gave no response at all, indicating that they

were devoid of taste-organs. Of the remaining ninety-eight,

twelve reacted to succinic acid alone, three to sugar alone,

while none were acted upon by quinine alone.

This would seem to give evidence that there are separate

nerve fibers and endings for each fundamental sensation, but

the experiments at least show that there is more than one

variety of taste fibers in the majority of the papille.

Strong evidence of this specific difference between various

nerve fibers is found in the fact that the same substance may

excite a different gustatory sensation according as it is applied

to the front or the back of the tongue. Thus it has been

demonstrated by Howell and Kastle#? that a certain com-

pound of saccharin (para-brom-benzoic sulphonide) appears

to most persons to be sweet when applied to the tip of the

* I donot pretend to give a complete historical sketch of this part, but only what came

to my attention, while looking up the anatomy and development, and whatever may throw

light upon the rest of the matter here given.

+ This part of the tongue is almost entirely devoid of papillz also.

132 A. E.- LOVELAND:

tongue, but bitter in the region of the circumvallate papille.

But very little seems to have been done upon the physio-

logy of these organs, and there is ample opportunity, there-

fore, for much more.

ANATOMY AND DEVELOPMENT.

Historical Sketch.

Waller3, 1849, was one of the first to study the organs of

taste, doing so in the frog. He was followed by a number of

others who obtained various results [see bibliography up to

1867], but microscopical technique had not been sufficiently

perfected before Loven’ and Schwalbe”, 1867-68, pursued

investigations upon these organs, and studied them simul-

taneously in mammals and in man. ‘Two kinds of sensory

cells were first described by these authors. One comprises

the taste-cell of Loven, with which the needle-cell (stiftchen-

zellen) of Schwalbe is identical, and the other the staff-shaped

cell (stabzellen) of Schwalbe ; the latter being broader, less

numerous, and less refractive.

Szabadfoldy and Letzerich™®, 1868, Engelmann”, 1868,

Beale?°, 1869, Maddox, 1869, Von Wyss”, 1869, Krause?3,

1870, Schulze*5, 1870, Ajtai, 1872, and Dittlevsen”, 1872,

did work on the organs of taste, but their results were indefi-

nite and are best summed up by Engelmann*, 1872, (in

Stricker’s Handbuch) as follows: These buds are found in

the circumvallate and fungiform papille of all animals, and in

the papille foliate of the rabbit, where they are particularly

well developed. The buds lie in flask-like cavities of the

epithelium which they completely fill, the wall of the cavity

being formed by the epithelial cells themselves. The cells lie

in very closely compressed rows around the axis of the bud,

arranged like the leaves of a bud. ‘They are composed of

two kinds of cells as previously described by Loven and

Schwalbe. The organs of the frog have three kinds of cells,

principally, the forked cells (cells with forked processes), the

broad goblet cells, and slender columnar cells.

A STUDY OF THE ORGANS OF TASTE. 133

Most of the investigations following Engelmann up to

Ranvier#, 1882, viz., Jobert®, 1872, Klein, 1872, Hoing-

schmied3", 1873, Hoffman33, 1875, Krause3>, 1876, Shofield3°,

1876, Lannegrace, 1878, Merkels?, 1880, Vintschgau*,

1880, and Gottschau#!, 1882, added little of value to that

previously done, all agreeing to two orders of cells in the

buds—the sensory cells and supporting cells—the former

being given the name of gustatory cells proper because they

approach nearer tonerve elements by their form, their pro-

perties and their relation tothe peripheral nerves. The only

divergencies consisted in a subdivision of the second group

based upon their form and the relative size of their prolon-

gations.

Merkel, 1880, added besides that these supporting cells

or covering cells (cellules de revetement or de soutien) were

found as well in the interior as on the borders of the buds.

During this time Sertoli, 1874, using the method of

impregnation by the gold-salts, discovered a very rich system

of non-medullated nerve fibrils which spread out at the base of

the papilla. Contrary to the opinion of all the other authors,

this author together with Krause%5, 1876, alone observe that

the nerves do not connect directly with the epithelial ele-

ments, but describe a plexus of fibrils having such complicated

terminations, that their exact mode of termination these two

authors were unable to establish.

Hoffman33, 1875, added to the observations of the others

‘these facts, that embryonic taste-bulbs could be found in the

fungiform papilla of a four and one-half months fetus, and

in the epithelium lining the epiglottis.

Kleins*, 1872, in studies upon development, made the

observation that in newly born children, owing to the indis-

tinctness of the wall in most instances, no difference is per-

ceptible between the circumvallate and fungiform papille.

Ranvier*?, 1882, verified the preceding results and made

an excellent study of these organs. He describes the gusta-

tory cells as elongated spindle-shaped, with a tapering cen-

134 A. E. LOVELAND:

tral prolongation terminating in a homogeneous knob-like

ending. They possessed an oval nucleus elongated in the

longitudinal axis. The supporting cells were flatter and more

irregular, with a larger nucleus, and terminating ina point at

their peripheral extremity. Ranvier used the impregnation

method with gold chloride, and showed the existence thereby

of intra-epithelial nerve fibrils, but he believed, also, that

other fibers came into direct connection with the sensory

cells. Heseems to have been the first also to describe the

multipolar cells now recognised by all.

After Ranvier, investigations upon these organs followed

two lines of work ; one upon the nerves and nervous relation-

ship of the organs, the other upon the development and genetic

relationship, some authors working upon the development and

others upon the nerves. Inthe continuation of this historical

sketch the work done upon the nerves will be given first and

the work upon the development of the organs afterwards.

In the study of the nerve relationship but little was added

up to the time of Retzius5*, 1892. Investigations followed

the results of previous writers, agreeing with them that the

nerves were connected directly with the sensory cells of the

bulbs and in other essentials. Drasch*+, 1883, alone observes

that the direct continuity of the sensory cells with the termi-

nations of the glosso-pharyngeal nerve he was unable to make

out, but in a later article and upon further examination

(Drasch#, 1887,) he concurred entirely in the belief of direct

continuity between nerves and sensory cells. According to

him the glosso-pharyngeal nerve terminates as follows in the

papilla ; The larger part goes to terminate in free extremi-

ties in the spaces between the epithelium of the bulb; the

other fibers, sufficient in number to supply the cells, terminate

directly in the gustatory cells.

The other authors who worked upon the nerve relationship

were Rosenberg?®, 1886, who described the multipolar cells

carefully ; Schwalbe*7, 1887, who wrote now for the second

time upon these organs, and Fusari et Panasci5?, 1891,

A SPUDY OF THE ORGANS: OF TASTE. 135

students of Golgi, who confirmed the work of previous authors

in extensive observations upon these organs. Tuckerman,

also, while studying the development of the organs, observes

that the sensory cells are developed from the peripheral

extremities of the nerve fibers, thus making these cells epi-

blastic in origin.

Retzius**, 1892, and Von Lenhossék®, 1892, followed by

Arnstein®3, 1893, carried out new researches after the method

of Ehrlich and Golgi, and arrived at just the opposite conclu-

sions from the preponderance of evidence adduced by pre-

vious authors. Their conclusions were that the nerves were

mot continuous with the sensory cells, but ended bluntly in

close proximity to them, and were distributed around and

betweenthem. Retzius and Von Lenhosseék described a plexi-

form envelope of nerves in the form of a basket which sur-

round the bulbs externally, and which they call peribulbar.

Arnstein, for his part, has seen the cells of the bulbs individ-

ually invested and covered with nerve fibrilli applied to the

surface of the cells, but never penetrating their interior, and

believed that these nerves, without doubt, proceeded from

the glosso-pharyngeal nerve.

Retzius and Von Lenhossék have also shown the multi-

polar cells, described by their predecessors, present in the

sub-epithelial layer, but both deny their being of a nervous

mature; Retzius, because he could not observe their connec-

tion with any nerve fibril, and Von Lenhossék, because of

their morphological characters.

Jacques®, 1893, in the latest and most exhaustive study

upon these organs, particularly in regard to their nerve con-

mections, conducted investigations upon the rabbit, dog, pig,

goat, cat, sheep, rat, mouse, mole, squirrel and man. Using

the method of Golgi with some special modifications, he

obtained excellent impregnations to demonstrate the cells and

merves of the bulbs.

136 A. E. LOVELAND:

I. THE CELES:

He found the two kinds of cells previously described, the

sustentacular and the sensory cells. The former are dis-

tributed throughout the entire bud instead of being placed

as enveloping cells on the exterior (so described by some

authors. )

The sustentacular celishave a body occupied by a nucleus,

centrally located, and two prolongations, central and peri-

pheral. The peripheral extremity is conical and ends at the

gustatory pore ; the central extremity is habitually enlarged

or swollen into an enlargement at the end, which frequently

divides into several branches of irregular contour. Of these

branches there are an irregular number, usually two ; some

extend to the extreme inner limit of the bulb, and others,

attaining much shorter distances, are reduced to mere spines.

The gustative cells also have a body occupied by a nucleus

which is oval in shape in these cells, and the position of which

is very inconstant, but is more generally situated near the

pore than near the base of the bulb. Agreeing with Schwalbe,

the author found the peripheral expansion to be thicker than

the central, and to end at the gustatory pore usually in a

knob-like ending. Schwalbe had divided these cells into two

varieties from the fact that some ended in a knob (stabzellen)

and others ina point (stiftchenzellen), but Jacques thinks this

simply a variation in the mode of ending of the same cell.

The central extremity is usually single, rarely bifurcated, and

ends bluntly or is enlarged into an irregular swelling at the

end. In opposition to the early investigations, but agreeing

with Retzius, Von Lenhossék and Arnstein, this extremity is

nowhere in connection with the nerve fibrils surrounding it~

II. NERVE TERMINATIONS.

The nerves arrive at the base of the papille in bundles and

pursue various ramifications, to the sides and top, where are

given off the fibrilli usually perpendicular to the main bundles,

A Si UiDNes OFS EE Ol GAN SiO qwA Sieh. WV 7E

and which enter or surround the taste-buds by processes

described below. Whether in these ramifications they actually

unite in a network, or simply interlace without uniting, the

author is uncertain, but he believes that the latter is true.

In the distribution of these to the buds themselves the author

found them pursuing three courses of supply. (1). The

‘« fibers perigemmal” which surround the buds in an envelop-

ing plexus, before described by Retzius and von Lenhossék ;

(2)>, the) <“fibers: intergemmal,, ior, those..that’ penetrated

between the buds; and (3) the ‘‘fibers intragemmal,” or

those entering the buds themselves, being distributed between

and around the cells.

The first and second are entirely extra bulbar, only the

latter penetrating within the bulbs.

The fibers intergemmal pursue a nearly straight and

parallel course between the buds, and end in the vicinity of

the epithelium, some terminating in small knobs, but the

greater part turning upon themselves at a right angle, to con-

tinue in the bed of superficial epithelium, and end there in an

oval or rounded enlargement. Many of them, however, form

half or complete circuits, fish-hook forms, and various other

forms. In some animals (cat) these fibers are seen to divide

dichotomously, but whether they actually anastomose is uncer-

tain.

The fibers perigemmal apply themselves closely upon the

whole surface of the bud, and enveloping it altogether as a

fillet, are directed towards the gustatory pore. Where the

impregnation was complete, these were never seen to end at

the pore, but to give off collateral branches, which -often

ended in knobs or points as in the first group, after circuitous

courses in the epithelium about the bud.

The fibers intragemmal enter the bulb, penetrate it in

various directions, and some terminate in the vicinity of the

pore, after having given off collateral branches ; while others

turning upon themselves one or many times, terminate by

swollen ends in various parts of the bud, or form minute

138 Ay Ee BOVEBAN D?:

plexuses about acell. In no instance, upon close observa-

tion, were any fibers found in direct communication with the

extremities of the cell. Appearance of such connection

always vanished after judicious and careful use of the micro-

scope, although close apposition of the fibrilli to the cells

were often apparent. No clear signs of anastomosis of these

with the intergemmal or perigemmal fibers could be distin-

guished.

SUB-EPITHELIAL CELLS.

The existence of bipolar and multipolar cells at the base of

the buds and the papille had been demonstrated by Kan-

vier?, Rosenberg*®, Schwalbe’?7, Hermann3, Drasch*,

Retziuss*, and Von Lenhossék®, and this author found the

same thing. These were usually bipolar, rarely multipolar,

possessed an oval nucleus, the two poles or prolongations being

of varied length, and terminated abruptly, but in some cases

were seen in actual continuation withthe nerve fibers. Insome

cases. these prolongations offered the characters of axis-cylin-

ders and continued by a fine varicose fibril a longer or shorter

course. In comparison with other nerve cells, these seem to

indicate that they are of the same nature, and the author is

inclined to think they are, and that thus these organs are

intermediate in character between the bipolar cells of the

olfactory organ, and the nerve cells of the cochlear ganglion.

This hypothesis must yet be verified.

In conclusion, the author thinks that neither the sustentacu-

lar or gustative cells so-called are nerve cells, but following

the hypothesis of Retzius may be called ‘‘secondary sensory

cells,” that is that they are simply auxiliaries to, and ele-

ments in, the production of the impression of taste upon the

nerves.

Other authors, as was referred to above, studied only the

development of the organs. Klein3°, 1872, made some studies

upon the development and Poulton*#3, 1883, directed atten-

* Data obtained from Tuckermann.

A STUDY Oh THE ORGANSTOR, TASTE: 139

tion to the sub-epithelial nature of the taste-bulbs, basing his

conclusions on the appearance as presented in Parameles and

Ornithorynchus, with the conception that the primitive term-

inal organ of the Ornithorynchus was replaced by one epithelial

in character in the highermammals. He also regarded the

gustatory ridge of the Ornithorynchus as an intermediate form

between the circumvallate and foliate types, found in higher

mammals.

Lustig#, 1884, however, made the most complete of the

early studies upon the development, and studied these organs

in both the rabbit and man, but failed to discover them at all

in rabbit embryos. In a rabbit 120 m.m. long, that had

lived thirty-six hours, the papille (circumvallate and foliate)

bore taste-bulbs in various stages of development. In the

human tongue five circumvallate papilla were found by this

author in a fetus of the fifth month, the earliest fetus he

examined, but no taste-bulbs were found. Ina fetus of the

seventh month seven circumvallate papille were found and

well defined taste-bulbs in each.

In a fetus of eight months the bulbs still showed their

embryonic character, but bulbs existed on both the free sur-

face and the side, those in the younger fetuses being only on

the free surface. Ina mature still-born child all the papille

possessed bulbs, but they were mainly on the lateral areas

[a few on the top] and differed in size, form and arrangement

from the adult.

Griffinis*, 1887, and Hermann both studied the develop-

ment of the organs of taste, Griffini mainly by excision of

the papilla, in order to study their regeneration, and Her-

mann chiefly in the embryos of rabbits. Griffini noted that

the bulbs first made their appearance from the sixteenth to

the twentieth day after excision of the foliate papille of the

rabbit, but not until the fortieth day in the circumvallate

papilla of the dog. The bulbs lie partly in the mucosa at

first. Following section of the glosso-pharyngeal nerve,

taste-bulbs begin to degenerate within twenty-three hours ;

140 A. E. LOVELAND:

the gustatory cells first, then the supporting cells. From

the seventy-sixth day after the division of the nerves, bulbs

are seen in early stages of development and the axis cylinder

is observed to regenerate and penetrate the epithelium, while

the latter cells place themselves about the nerve fibrilli.

Hermann’s studies were chiefly upon the rabbit and he

observed on the circumvallate papilla of an embryo rabbit of

50 m.m. length, taste-buds in the first stages of development.

The earliest forerunners of definite taste-buds he observed in

the form of modified basal cells of the epithelium.* The

gustatory papilla are developed in the rabbit during the

latter period of intrauterine life and in the first few days

following birth.

Tuckermann®, 1888-89, has done elaborate work upon the

development of these organs in both men and animals.

Nothing but a brief summary can be given here.

The papilla foliatea, found in many mammalia, were dis-

covered by this author in the human tongue, reaching their

highest development about birth, but appearing as early as

the fourth month in the fetus.

Taste-buds were first found in a fetus of fourteen weekst

and circumvallate and fungiform papillae (in the forma-

tive stage) first at this period. The taste-buds were dis-

tinctly subepithelial, two-thirds of the bud lying in the

mucosa.

In a fetus of the fourth month five circumvallate papilla

were found, many fungiform papilla and a few foliate papille

in the formative stage. .

In a fetus of four and one-half months, six circumvallate

and numbers of fungiform and foliate papilla were found, the

latter stillin the formative state. Taste-buds were found in

all stages of development, some subepithelial in position and

some lying partly in the mucosa and partly in the epithe-

* He would thus make them hypoblastic in origin. [AUTHOR.]

+ Other authors have considered stages of development by increase in length of the

fetus, as more accurate than estimations by age, a method I have been led to adopt in my own.

work. How this author determines the ages of his specimens he does not say.

A STUDY OF DHE ORGANS OF TASTE: I4I

lium. The taste-buds are all upon the free surface and none

upon the sides.

In a fetus of six months, eight circumvallate were present,

and numerous fungiform and foliate papilla, the latter still

only partly developed. Taste-buds are found upon all the

papilla, but are only embryonic in character upon the foliate

organs. The buds occupy the sides frequently of the cir-

cumvallate and fungiform papillae, but chiefly the upper

area.

In afetus of seven months, all the varieties of papilla are

present, and taste-buds are found upon all, but still occupy

the upper areas more frequently than the lateral. Buds are

found rarely upon the epiglottis and uvula. The stiftchen-

zellen (needle cell of Loven) and the stabzellen (staff cell of

Schwalbe) are distinguishable at this stage. The sensory cells

are seen to develop from the peripheral extremities of the

nerve fibers, and are thus epiblastic in origin.

In a child 28 days old the circumvallate papillz are all

perfectly developed, and taste-buds are-found mainly upon the

lateral areas of the papilla, rarely upon the upper surfaces.

Foliate papillz are here well developed.

In adult tongues the circumvallate papillz vary from seven

to tenin number, usually eight. Taste-buds are found entirely

upon the lateral areas of the papilla and are increased in

number. |

Hintze, 1890, also made considerable study of these

‘ organs, and worked particularly upon the human fetus. Ina

fetus of 50 m.m. length (referred, therefore, to the begin-

ning of the third month) was the first appearance of a papilla,

and the epithelium consisted at this time of two rows of cylin-

drical cells, with rounded cells lying directly upon them at

the surface. Papillz fungiform and circumvallate are both

present. Inanembryo, 64 m.m. in length, were the first signs

of developing taste-buds, some of the cylindrical cells arrang-

ing themselves in a whirl from which develop the taste-buds*.

* This agrees with Hermann in regard to genetic relationship, [AuTHoR.]

142 A. a WOVERAND:

These were found in the fungiform papillae. In this fetus

were the first signs of filiform papillz also.

The author examined in this way nine fetuses, marking the

progressive growth of the papilla, the oldest fetus being 410

m.m. long (280 m.m. vertex tococcyx). The minute devel-

opment of the buds themselves the author did not describe.

The taste-buds developed first upon the free surfaces, and only

as the fetuses approached full term did they appear upon the

sides. No signs of karyokinesis were discovered.

Niemack®, Rauber*®,

Following the bibliography will be found a short list of

those whom I found had worked particularly upon the taste

organs in other regions than the tongue. Besides these,

others who worked on the tongue have found the organs in

other. regions, notably Tuckermann, Gottschau, Shofield,

Honigschmied and Krause, with some others. I have not

followed these out in this brief article, but only referto them

to indicate that considerable has been done on other regions

than the tongue upon these organs. As was pointed out in

the introduction, they have been found upon the epiglottis,

the anterior pillar of the fauces and the uvula.

ORIGINAL RESEARCH.

In a study of the organs of taste two departments of inves-

tigation are open to the student: the development and the

nervous anatomy. Following these two departments the

present study will take up first the development of the organs

in the human fetus and, secondly, the nervous anatomy. t

* Being single publications, I was unable to obtain these authors’ articles.

+ This work was done in the private laboratory of Prof. H. B. Ferris, of the Medical

Department of Yale University, and Iam much indebted to Prof. Ferris for considerable

material and assistance given me.

A STUDY OF THE ORGANS OF TASTE. 143

DEVELOPMENT.

In the study of the development I was able to examine

sections from the tongues of twenty-four specimens”, two of

which were full term. Inthe description of these, the best

method to follow seemed to be the use of the comparative

lengths rather than ages.

A reference to other authors’ works, together with an

examination of my own specimens, convinced me that the

age, as obtained from the usual sources of information, could

be little relied upon for accurate work. On the other hand,

it seems to me that in the first few weeks the agecan usually

be approximately determined by the length of the fetus, from

vertex to coccyx, or from the length of the spinal column

alone. The latter seems to especially merit our favor from

its necessarily constant ratio both to the size and age of the

fetus, and particularly because of its ease of accurate measure-

ment.

Minott asserts that weight is the only available measure of

the growth of the fetus as a whole. So many things, how-

ever, in the way of nutrition, change or conditions, mode of

preservation, etc., cause the weight to vary, that a measure-

ment of the spinal column would seem to be a much better

indicator of the accurate age of the fetus than any other one

method of determination. Inasmuch as I have received the

tongue alone in some cases, with only the measurement of

vertex to coccyx contributed besides, I have been unable to

give here the spinal column measurement in all cases, and I

have, therefore, in my descriptions, referred to the lengths

as measured in toto from vertex to coccyx. This agrees also

with the method of measurement employed by Hintzes®. But

* It was owing to the kindness of New Haven physicians who have willingly responded

to my request for specimens, together with the aid of Dr. Adolph Meyer, who gave me six

specimens, that I have been able to give the results of work upon this number of fetuses.

+ Human embryology. Minot, 1892.

144 A. E. LOVELAND:

I have included in each case, where possible, the length of the

spinal column also, and should adopt such measurement in

future work.

In order to bring to hand at once a means of estimating

the age approximately from the length, I have collected sta-

tistics supplied by Minot, Lusk and other embryologists,

where the age of the fetus was in each case accurately esti-

mated from known data, and give below the lengths and age

in comparative columns:

14 days .. . . Lusk, 1.5 m.m. length vertex to coccyx.

23 he Apo) one lGs 7 lsnaeionl, “ “ ‘“

27-28 _ § His, Waldeyer,

( Miiller, 7-8 m.m. &< “ ée

29-30‘ ‘ { Minot,

Garigues, etc., 8-10 m.m. cs ‘ ‘

BI-32) Vy = ease ese ba1S), MiLemm. “ “ re

35 gs s) coos Hos HMett, £4). me “ “ 4,

38 4 IS ais arm cn. & “ ‘

40 5 . . . . Minot, Waldeyer, I9-20m.m. “ “ ‘

50 a a ses Munot.20=memn= ce ¢ “

60 eS 3). oe Minot;28: mim: « “ “

64 is + av.) < Minot, 32 mm: « “ «

75 a oo) ee Minot; 55, mm: “ “ ‘

3 months .. . . Minot, Lusk, 80-90 m.m. ‘“ “ “

BUOY . . . . Minot, 108-110 m.m. &« “ &

4 i - ... « Minot, 155 m.m. “ “ “

The above cannot include variations that must occur con-

siderably, but it gives a basis for estimate that may be relied

upon for approximate determination at least.

Below is given also, in tabulated form, the comparative

lengths of the fetuses examined by me, both in total lengths

and length of spinal column. The length of the tongue and

the approximate age of each is given also :

A STUDY OF THE ORGANS OF TASTE. 145

F ‘ Length from} Length of Tenethict ; No. of

Sree Reet tely | ronguey [hee sun oer Peg) pe ates

I 30 m.m. Leeda oT E38 | ake Mer fleece 8 weeks (2 mos.) oe,

2 Bowe ies eee Ne aoe ote Se ay omic tas joo

3 32 ZO Re ie So eae ce neha towree Mote 2 Se

4 Gor uc 5.5 m.m. LOW PRY Pal eset rept: Boots

5 TO ae 6 y oth PES i Sees 3

6 On Aah ks 7 es LO=1 Es ph Crs we nade 4

7 SOnnce AQ es’ 7 ce 12), eeu (Bymoss) 5

8 So) Onn 7 a 12 SM erate tae 5

9 OS Ome 15 we POST Se ee Panter etre &

Io OSia. as Ones 13 : Toe ee eer ia 6

Late Toor “< {ear 6 13 « BAW gh abate, te Sie 7

I2 EDScoue is 14 PASI p Cay beh Gree ae 7

13 F220, vives Te aes I “(4 mos.) 8

14 BZ0\F "5 ee 15 ‘ TIO? | HES leg Awe Yee? = 6

15 Abe act go, <5 15 VO=17 wy 155 8

16 rsa. es Th ae A A Ae ae Se 8

17 iifoye | Os) ais pp 5 U5ES ty eee Road Bion EOE 8

18 nies, OU O77) ws 17 € 1 C55 Oy aS me aes, cee 8

19 noon =< Io5 * 22 s Life) ig Se or 8h Sic Ma to 8

20 TOS ec HOM 24s. ant TO bh OOS nl elomor 4 8

21 Bae Me 2 tk MEAG) <o 2G. Tt 20; ) ‘(5 1n10S-) 8

22s Sj reaso. aoe te BOP) (LE Od eee 8

23 BOOT 20015 34 a 25a). (ome (OumOs:) 8

24 Ane Sie te 48 ce Full term. 8

25 lise)» | 240° 50 se Full term. 8

In studying the development of the taste organs the

embryologist must necessarily direct his attention equally to

the papilla within which they appear, and compare the growth

of both simultaneously. Up to the end of the second month

or in fetuses of 30-40 m.m. in total length, there is very

rarely any deviation from the homogeneous epithelium of the

hypoblast covering the tongue. But about this period there

appear definite layers of cells, consisting of a row of columnar

cells which lie upon the mucosa or mesoblast below, and

covering these cells the polygonal and flattened cells of the

superficial layers. The columnar cells are at first parallel

with the general contour of the surface, but they early show

signs of assuming a sinuous course, and in fetuses of 50-80

m.m. in total length (tenth to thirteenth week) the embryonic

papillz are seen in all stages of development. (Fig. 1). It

* Not examined microscopically.

146 A. E. LOVELAND :

will be remembered that Hintze5° noted the first papille in a

fetus 50 m.m. in length.

There were three specimens which I examined, younger

than the tenth week, two of which were each 31 m.m. in

total length, 18 m.m., length of spinal column, and the third

was 32.5 m.m. in total length, and 20 m.m. length of spinal

column. In these the epithelium was homogeneous and

undifferentiated.

There were also three specimens between the lengths 60

to 70 m.m., and in these papilla were present in various

grades of development. Two of these were each 70 m.m. in

length, spinal column 43 m.m., and the third was 60 m.m. in

length, spinal column length undetermined.

It is usually in fetuses further developed than the last, that

is, in those from 80-110 m.m., that the taste-buds themselves

are first seen. Hintze observed the earliest taste-bulbs in a

fetus 100 m.m. in length, or in a fetus of about the fourteenth

week, and Tuckerman also in one of the fourteenth week.* In

my own observations there were two fetuses each of 80 m.m.

length, spinal column 49 and 50 m.m. in length (about the

twelfth week therefore). In both of these the papillae circum-

vallate, of which there were five in both cases, were beginning

to assume their characteristic form, but were below the surface

epithelium, and in neither case showed any signs of taste-buds.

The papillz foliate were beginning to form, but were embry-

onic in character, and enclosed within the epithelium. The

fungiform papillz in one of the specimens were likewise only

partially developed, but in the other they were well advanced

in growth and their tips were elevated .05 m.m. above the

surface of the surrounding epithelium. In one ofthese, situ-

ated on the side and at the base of the tongue, was distinctly

seen a taste-bulb with but few cells, and only partially pro-

truding into the epithelium of the papilla in which it was

growing. About half of its length lay imbedded in the sub-

* As was noted before, how Tuckerman estimated the age, either in this case or in all

his work, he does not say.

A STUDY OF THE ORGANS OF TASTE. 147

epithelial connective tissue below. (Fig. 2.) This is the

earliest appearance of a taste-bud that I have found recorded,

and does not probably represent the average period of appear-

ance. In another fetus, as long as 115 m.m., no signs of

taste-buds were discoverable, although they probably were

present. This indicates considerable variation in the time of

the appearance of the buds, and inasmuch as Tuckerman*

and Hintze*® have both found them only from the fourteenth

to the sixteenth week, and others not until the eighteenth or

twentieth week, (Hoffman 33 and Lustig*>), the fourth month

would seem to be more accurately judged the average period

of appearance.

The genesis of the different forms of papillae, whether from

a common early embryonic form, or each froma distinct indi-

vidual origin has been discussed by Tuckerman‘, Gmelin‘?

and Klein*°; the first two asserting that the development of

each form was too distinct to allow of any consideration of

the origin of one form from another, while Klein urges that

the embryonic papillz are indistinguishable from one another

in newly born children, and therefore of common origin. I

will say, from my own observations, that as soon as the

embryonic papille begin to form in the epithelium, while still

intra-epithelial in character, they assume at once the charac-

teristics of the papilla which they soon become. I therefore

regard them as genetically distinct in origin and develop-

ment. That a gustatory area exists in the Ornithorynchus

which is intermediate in form between the circumvallate and

foliate types in the higher mammals is urged by Poulton# and

might seem to indicate a development of the circumvallate

from the fungiform papille. But the simultaneous appear-

ance of each in the human tongue is more indicative of inde-

pendent origin.

The fetuses next in size that came under my observation

were two, each 95 m.m. in length, spinal column 58 m.m.,

and 56 m.m. respectively. In both of these specimens the

circumvallate, fungiform and foliate papillz were in the first

148 A Bs BOVEUANI::

stages of development, though easily distinguished in charac-

ter (Figs. 3 and 4). There were embryonic taste-buds to be

found upon one or two of the circumvallate papilla, of which

there were eight present in one, and six in the other.

Fetus 100 m.m. in length was denuded of epithelium, so

no examination could be made.

Fetus 115 m.m. in length, spinal column 75 m.m., showed

no signs of taste-buds, although there were seven circumval-

late papilla present, and fungiform and foliate papille, all

partially developed. The whole appearance of the tongue,

however, was of that of an earlier stage than the size and age

of the fetus would indicate.

Two fetuses, one 120 m.m. in length, spinal column 75

m.m., the other 130 m.m. total length, spinal column unde-

termined: The first possessed eight circumvallate papille,

and the second, six. There was the same general appear-

ance in both of these. The fungiform papille by this time

are well developed and the foliate are forming rapidly, but

the latter possess no taste-buds. The circumvallate and fun-

giform papilla, however, have taste-buds which are largely

sub-epithelial, and are developing entirely upon the free sur-

face of the papilla, with none at all upon the lateral areas

(Fig. 3). They resemble very much in character the buds

observed in the fetus of 80 m.m. length, before described,

Fig. 2), and probably show the same stage of development,

but occur at a more usual period for the appearance of the

buds than the latter.

Fetuses from 145 to 152 m.m. in length, the measure-

ments of these were as follows: The first, 145 m.m. total

length, spinal column 90 m.m. Two were 150 m.m. total

length, spinal column 95 m.m. The fourth was 152 m.m. in

total length, spinal column 97 m.m. The first and last of

these were tried with silver nitrate impregnation, to observe

the nerve terminations, but they had evidently been dead too

long before the trial was made and no results were obtained,

although one of them was received six hours after birth. In

A STUDY OF RHETORGANS OF TASTE. 149

the two specimens, each 150 m.m. in length, and referred,

therefore, to about the fourth month, the circumvallate, fun-

giform and foliate papillae are quite well developed. Taste-

buds are found on all the papille, here for the first time

observed upon the foliate papille. They are present only on

the upper surface of the papillz, and are still partially sub-

epithelial in position. (Figs. 5 and 6.) The foliate papille

are thus seen to develop later and more slowly than the

circumvallate or fungiform, and Tuckerman has shown that

they do not reach their fullest development until the first

months of childhood. In the rabbit they happen to have

reached a highly specialised form, and though circumvallate

papille are present in this animal, the foliate organs carry on

the functions of taste more than the circumvallate organs do,

and should be regarded probably of equal rank with the latter

and not as a lower form.

It has been noticed that the taste-buds are first seen partly

enclosed in the hypoblast and partly included in the mucosa

below, and that in their formation the cells themselves occupy

a position between both (Figs. 2, 3, 5 and 6). This would

seem to indicate an origin other than hypoblastic, and Tuck-

erman, following other embryologists, considers that these

cells originate from epiblast, and are derived, therefore, from

the same source as the nerves themselves. Tuckerman

describes them developing with the surrounding nerves, and

the latter folding themselves about the cells as they grow.

This agrees also with the discovery of Von Lenhossék* that

.there are cells scattered through the epidermis of the earth-

worm, which give off fibers that run to the central nervous >

system, and there like sensory fibers, fork ; one fork running

headward and the other tailward within the central ganglionic

chain. This leads the discoverer to the hypothesis that the

special sense-cells connected with nerve fibers, as in the

olfactory membrane, are true neuroblasts, in that they pro-

duce the nerve fibers connected with them. Believing, like-

* Ganglia. His Archiv., 189r.

[50 A. BE. EOVELAND :

wise, that the sense cells of the organs of taste were connected

with the nerve fibers, Von Lenhossék considered them neuro-

blastic cells. Since further study upon the subject has

changed the view of the connection of these cells with nerve

fibers, the neuroblastic or epiblastic origin is no longer sup-

ported as strongly. There is no reason, however, why these

cells should not be epiblastic, and be developed singly here,

in the same way that the sensory cells of the retina are sup-

posed to be developed.

On the other hand, by the conception of Retzius that

the cells of the taste-buds are only ‘‘secondary sensory

cells,” and act simply as auxiliaries to. and elements in, the

impression of taste upon the nerves, these cells may not be

neuroblastic at all, but may be either hypoblastic or meso-

blastic.

As was shown before, studies of Hermann and Hintze

would indicate that they were hypoblastic, but since they

develop from a sub-hypoblastic position they may be meso-

blastic. Again, a separate origin for the sensory and support-

ing cells is not improbable and will be discussed later in this

paper, 7. e., epiblastic origin for the sensory and mesoblastic

or hypoblastic for the supporting cells. Such a supposition

explains the fact that at their appearance the embryonic buds

are partly buried in the mucosa, by the supposition that the

sensory elements develop and appear first and are then

wrapped around by the supporting cells of the hypoblast or

mesoblast ; according to Hermann, Hintze and my own

observations more probably hypoblast. Until the proper .

staining methods can be applied to embryos at the right

period for the complete study of this, the subject must

remain unsettled. The cells of the early taste-buds certainly

appeared in my own observations to be modified cells of the

basal epithelium forming the hypoblast, but my specimens

were not suitable for special staining methods and I can only

speak from the use of ordinary methods.

Fetuses 160 and 165 m.m. in length, the spinal column

AYSTUDY OF THE ORGANS OF TASTE. I5!I

measurement in these being 105 m.m. and I10 m.m. respect-

ively: All the varieties of papillae are well developed and

taste-buds are found in each, partially occupying the upper

surface and partially the latter portion of the papille (Fig. 7).

In respect to the epithelium the buds are by this time well

imbedded in the epithelium and are rarely sub-epithelial in

position. It is here for the first time that the taste organs are

found approaching the sides of the circumvallate papilla, a

position that they occupy solely in the adult, and also in the

newly-born child buds are found mainly upon the lateral sur-

faces. This gravitation to the sides and base of the papilla

from an original position upon the upper surface is confirmed

by all authors.

Fetuses 125 m.m. and 130 mm. in length, spinal column

140 m.m. and 150 m.m. respectively: All varieties of

papille are present and taste-buds are seen over the entire

area of the circumvallate papilla, but with a much larger

number at the top than upon the sides. In the fungiform

and foliate papilla they are also occasionally seen upon the

lateral surfaces, but in the latter particularly are more

frequent upon the top (Fig. 6).

The filiform papilla described by some authors, which are

more slender and somewhat longer than the fungiform or

foliate, I was unable to discover earlier than in these speci-

mens just described. Here they were present, but were

embryonic in character. On the tip of the tongue no taste-

buds were observed upon any of the papille.

Fetus 300 m.m. long and spinal column 200 m.m. long:

Taste-buds are found upon the entire area of the circumval-

late papilla and upon the top chiefly of the fungiform and

foliate papilla, at the back of the tongue. On the tip of

the tongue, no taste-buds at all are found upon the lateral

surfaces of the papillze found in this region, the fungiform

and filiform. It is thus seen that the taste areas develop first

and more rapidly at the back of the tongue and later and

more slowly upon the tip of the tongue. It is needless to

152 A. E. LOVELAND’:

say that the papillz foliatee and the circumvallate papille are

found only at the back of the tongue.

Many taste-buds found at this period are well developed,

are little different from those found at birth (Fig. 8), are

about the same size as those at birth and contain about the

same number of cells. It was noticed in the early speci-

mens that the buds contained but few cells at first ; but as

the organ grows, more cells appear, until, at the maturity of

the bud, there are usually from sixteen to twenty cells in

each bud, as opposed to about six at first. Many of the

circumvallate papillae of six months, however, have buds

still undeveloped and disposed to a large extent upon the

upper area.

There are, in fact, at this age buds in most all stages of

development, some even still partly sub-epithelial in character.

SUMMARY.

From the preceding it will be seen that the taste-bulbs

appear generally about the fourteenth week, or in fetuses of

100 to 120 m.m. length, 60 to 75 m.m. by length of spinal

column. But they may appear as early as the twelfth week,

or in fetuses 80 m.m. in length, 50 m.m. in length of spinal

column.

The buds appear first below the epithelium forming the

mucous membrane of the tongue and gradually migrate into

this, until, by the end of the sixth month, they are usually

imbedded entirely within it. The epithelium of the tongue

being hypoblastic in origin, this process would seem to indi-

cate an origin other than hypoblastic for the taste cells, but

they are nevertheless developed from the hypoblast, prob-

ably, as these and other observations show, unless the sen-

sory cells alone may have a separate origin from the epiblast.

More special work must be done here before it can be deter-

mined precisely.

The buds appear at first upon the upper surface of the

papille and, in the circumvallate, gravitate, as the papille

A STUDY OF THE ORGANS OF TASTE: 153

develop, toward the sides and base of the papille, becoming

at the time of birth almost entirely basal in character; in

the other varieties of papilla they occupy both the top and

sides up to the time of birth, and unlike the circumvallate

papillz, which always carry taste-buds upon them, these only

occasionally possess them.

The papilla themselves begin to develop in fetuses 50 to

70 m.m. in length, 30 to 45 m.m. in length of spinal column,

about the tenth week. They assume their characteristic

forms at once and at the fourth month are elevated consider-

ably above the epithelium of the mucous membrane. With

the exception of the filiform they are usually fully developed

by the fifth month. The fungiform papilla seem to develop

first, then the circumvallate and the foliate and lastly the

filiform, which appear about the fifth month. The genesis of

the different forms of papilla are distinct and are each

developed individually, no one form passing into another.

The taste areas develop earlier upon the posterior portion

of the tongue than upon the anterior portion and tip of the

tongue and are much more numerous upon the former.

II.

NERVE TERMINATIONS.

The subject of the nerve terminations and their relations

to the cells which form the organs of ,taste have furnished

much field for investigation and research. Because of recent

contrary views upon the question of the relation of the nerve

fibrilli to the sensory cells, this present paper was under-

taken. After giving in some detail the methods employed

for this particular study, the results will be presented.

TECHNIQUE OF THE METHODS PURSUED.

Two methods of staining the nerve fibrilli of the taste

organs were used. One, the old method of Golgi, by

impregnating the tissue with chromate of silver, and the

154 A. E. LOVELAND :

other an entirely new method of staining with methylene

blue.

Golgi Method.—The silver-chromate method is the one

described as Golgi’s rapid method. By this method the

tissue must be fresh, that is, must be used within a few hours

after death. Some authors have been successful with tissues

not prepared until twenty-four hours after death, but in my

work I found that after six or eight hours the nerves would

not receive the impregnation. The tissue tried, however,

were fetuses, age about four months, and no dependence can

be placed upon how long they may have been dead before

expulsion from the uterus.

Either pure bichromate of potash may be employed or

liquid of Miller. Small pieces of the tissue are thrown

into the following mixture :

Bichromate solution, 2 to 2.5 per cent.strength. . . 8 parts.

Osmic acid, of I per cent. strength ....-.. - 2

The hardening being much more rapid than with the slow

method, the tissues will begin to be in a fit state for taking

the silver impregnation from the second or third day. My

custom was to remove from the bichromate solution after

thirty-six to forty-eight hours. I seldom found, however,

that the silver salt would act thoroughly at this first trial and

the specimen was brought from the silver bath a second time

into the bichromate solution for twenty-four to forty-eight

hours, after which it was transferred a second time to the

silver bath. A third time was necessary in some cases and

this was usually successful, but even a fourth should be tried

before failure is reported. As the tissue lies in the silver

bath twenty-four to forty-eight hours, the third repeated

immersion will, it will be seen, bring the tissue to about the

twelfth day from its first immersion, after which time little

success can be expected.

The impregnation with silver nitrate requires from twenty-

four to forty-eight hours. As soon as the pieces have

A STUDY OF THE ORGANS. OF TASTE. 155

attained the proper degree of hardening in the bichromate,

they are brought into the bath of nitrate of silver. The usual

strength of this bath is 0.75 per cent., but any strength from

0.50 to I. per cent. may be used. Relatively large portions

of the solution should be employed, at least 50 c.cm. of

liquid to I c.cm. of tissue.

The moment the pieces of tissue are thrown into the silver

bath, an abundant yellow precipitate of chromate of silver is

thrown down. This, of course, weakens the solution and, if

fine surface impregnation is desired, will so cover the surface

epithelium that a clear picture of the final terminations is

impossible. In most of the work upon nerve tissue of the

central or peripheral system, this would not interfere, but in

tracing the nerve fibrilli to their terminations in the super-

ficial epithelium such a precipitate renders the view very

indistinct. To prevent this, the specimen, after removal

from the bichromate bath, is washed gently in distilled water

and then immersed in gelatin, which has been warmed just

to the melting point. The gelatin hardens at once and forms

a coating around the specimen, preventing any precipitate

forming when immersed in the silver and at the same time

impregnation can go on as usual.

If there is no reason for using the gelatin, it is well,

before putting the pieces into the final silver solution, to

first wash them in a weaker solution, until, on being put into

a fresh quantity no further precipitate is formed. Solutions

already used will do for this purpose. This final silver bath

needs little attention, except in case it should become yellow,

when it should be changed for fresh.

It is not necessary to keep the preparations in the dark,

but Lee says that in winter it is better to keep them ina

warm place. Although the impregnation takes place within

forty-eight-hours, usually, ‘‘tissues may remain in the bath

without hurt for days, weeks or months.” (Lee’s Vade-

mecum.

In regard to preservation of the specimens, as soon as a

156 A. E. LOVELAND:

trial has shown sufficiently satisfactory impregnation, they

are brought at once into alcohol. A trial can usually be

made by making a free hand section and observing with the

microscope. In this rapid method the specimens should not

remain too long in alcohol, not more than two days, and are

then transferred to either celloidin or paraffin. Some authors

recommend the former as superior, but in my work I found both

equally good, with the exception that if the celloidin block is

left too long in alcohol before cutting, the impregnation is

apt to wash out. With paraffin, on the contrary, I found the

specimens could remain for weeks without change.

Sections being made they must be washed thoroughly in

absolute alcohol, several changes, and then cleared in clove-

oil, turpentine or creosote, where they should remain for ten

to fifteen minutes (they may remain there for days without

harm). Clove-oil was used almost altogether in my own

work. They are then mounted in balsam (some authors say

Damar is better, but I found no trouble with balsam), and

without a cover.

I would like to repeat, in regard to successive impregna-

tions, that in no case was I successful with the first trial at

impregnation, but after repeating the immersion in both solu-

tions for the full period, the impregnation seldom failed,

although a third or a fourth was necessary in one or two

cases. By this method excellent results were obtained and

the investigations of recent authors verified.

Methylene Blue Method.—Methylene blue is the chloride or

the zinc chloride double salt of tetramethylthionin and is

distinct, therefore, from methyl blue, which is derived from

diphenylamine blue. The properties of this especial form of

blue were discovered by Ehrlich*, in 1885, and it has since

then been used so successfully that it seems now to be effect-

ing a revolution in histological technique. This color for

staining nerve tissue must be as pure as possible and the

histologist should make sure of obtaining only the pure, if

* Abh. K. Akad. Wiss. Berlin, 188s.

A STUDY OF THE ORGANS OF TASTE. 157

he will have success. The methylene blue, made by E. Merck,

of Darmstadt, or by Gribler & Co., can be relied upon. The

stain of the latter was used in the work done by the author.

The peculiar property of this stain in selecting the axis

cylinders and the success reported by its use upon both the

central nervous system and peripheral nerves led me to

attempt a trial of it upon the organs of taste. All previous

work upon the taste organs had been done by the use of

either the silver or the gold method and it was to compare

results of ¢thzs new method with those obtained by the other

that the present research was undertaken.

The method which after repeated trials finally gave me

signal results is the following :

Having obtained the pure article, a solution of 1:1000 of

O.5-0.6 per cent. salt solution is made and the tissue removed

from the animal that has just died is immersed at once in the

solution for fifteen minutes to a half hour. Only experience

can determine how long to leave a given specimen in the

solution, for the stain is precarious and will reach a maximum

degree of coloration in a short time, after which the nerves

begin to discharge their color even more quickly than they

take it up. Thus it is often found that the elements that

have stained first, which are the sensory nerve fibers, will

have lost most of their color by the time the remaining

elements of the tissue are stained, such as muscle, connective

tissue and the like. I made this mistake early in my work—

z. e., of leaving the specimens in the solution for hours,—

thinking the thickness of the epithelium would require it, but.

in all cases the nerve elements were unstained. Thus the

objects, if not more than a centimeter in thickness, should

usually be immersed no longer thana half hour. By this

method and by using specimens removed while the animal

was still warm, I arrived at very satisfactory results. I

regard the obtaining of the specimens as fresh, as was just

stated, very important, since in several cases where I tried

impregnation an hour to four hours after death no results were

158 A. E. LOVELAND:

obtained at all, with either weak or strong solutions of the

stain. And this is rendered still more an essential feature in

the method, from the fact that the intra-vitam staining by

injection gives the best results.

As to the strength of the solution, the best stain was

obtained with the solution 1:1000 of physiological salt solu-

tion, although strengths of 1:300, 1:500 and 1:2000 were

tried for comparative results.

After the staining there are two methods of examination,

one by immediate examination in a glycerin solution, after

treating an hour with ammonium picrate, and the second by

fixing with Bethe’s solution of ammonium molybdate and

mounting in paraffin or celloidin. .

The first is a rapid method, but will only do for very thin

specimens that do not require cutting and I found it entirely

unsatisfactory in working upon these organs.

The second method, recommended by Bethe*, I found

very successful. A solution is made of the following :

Ammonium-smolypdate ts vedi eels ses aie I grm.

Distilledswate neem. ee-ur-1e cree ME men an-reCnn EANLOS

Heroxmdelol hy Groren sey ilags ean Monee Enon i

letitehqoys) allerciteavenGl) 3B ty Go IG Goo Gd ole << I gtt.

On adding the peroxide a yellow color is produced and when

the hydrochloric is added a white precipitate will be formed

which dissolves on agitation. After removal from the stain

and rinsing in salt solution, the preparations are put into the

molybdic solution. This solution should not be more than a

week old and is well to use cooled to zero if possible. The

specimens are left in this for three to ten hours, according to

size, when they are washed thoroughly in water for an hour

and transferred to alcohol. After thoroughly dehydrating,

two to twenty-four hours, they are cleared in xylol and

imbedded in paraffin, or after clearing in xylol are transferred

to alcohol, ether and celloidin. The paraffin method of

imbedding I used almost entirely and found it rapid and sure.

* Archiv. f. Mik. Anat. XLIV., 1894.

A STUDY OF THE ORGANS OF TASTE. 159

RESULTS OF THE RESEARCH.

The principal results were obtained from the papille

foliatz of the rabbit, although successive trials were made

upon the dog and the human fetus, with little or no success.

The human fetuses employed were not sufficiently fresh ; but

why no success was obtained with the dog’s tongue I was

unable to determine, unless the epithelial tissue surrounding

the taste organs in this animal are so impenetrable that not

sufficient exposure to the stain was made.

The results upon the cells of the buds will be taken up

first and the nerve terminations themselves afterwards.

The Cells.—Two kinds of cells are commonly described

as forming the taste-buds, the gustative or sensory cells

(Pl. II, Fig. 10) and the sustentacular or supporting cells

(Pl. IL, Fig. 9). Some authors, Loven", Schwalbe”, princi-

pally, and others divide the gustatory cells again into two

classes, the needle-shaped and staff-shaped, named thus on

account of their variation in ending, the former in a point,

the latter ina knob. In regard to this, it seems to me that-

Jacques® is right in thinking these to be but variations in the

terminal processes of the same cell and that these cells should

not be divided into distinct classes therefore (PI. III., Fig. 4

b,cand PER lirs Tigre):

The two kinds of cells were found by both methods,

staining equally well by both the Golgi and the methylene

blue. The latter was found to retain its color rather longer

in these cells than in the nerve fibers, the latter discharging

the blue stain very readily. It was noticeable also that the

gustatory or sensory cells (Figs. 1 and 2, PI. III.) were always

the first to stain with methylene blue and many sections

showed only these cells and the nerve fibrilli stained. Later

in the process the sustentacular cells stained, so that many

views of the buds gave a picture under this stain like Fig. 2,

Plate III., where the sustentacular cells were so little stained

that they were hardly visible. When the sustentacular cells

160 A. E. LOVELAND:

were fully stained, the sensory cells and nerve fibers had

frequently lost their color, while the connective and muscular

tissues were all well stained. Does this indicate a possibility

of common origin of the gustatory cells and nerves, and an

equally common genetic relation between the sustentacular

cells and connective tissue ?

The peripheral endings of these cells were found to be as

described by Jacques®, the sustentacular cells ending in a

conical extremity at the gustatory pore, and the gustative

cells usually in a knob at the same pore (Figs. 2, 3, 4, Pl. III.)

The vital question of the connection of the central endings

of the cells with the nerve fibers has been a matter of investi-

gation and dispute, so especial attention was paid to note

these extremities in the specimens stained. It will be remem-

bered that all the old authors, up to the time of Retzius, had

either boldly testified that the cells were in direct communi-

cation with the nerve fibers, or had concurred in the opinion

expressed by others to that effect, with the exception of

Sertoli3? and Krause%s5, who had on the contrary considered

that such observations were uncertain. Drasch*#, 1883, had

similarly announced the uncertainty of such direct communi-

cation, but later#®, 1887, in summing up the work done pre-

viously upon these organs, he concurred with the great num-

ber of investigators in the belief that there was immediate

connection. Tuckerman also, writing in 1889, observed

that the communication between the gustatory cells and the

nerve fibrilli was apparent early in the development of the

buds.

On the other hand, Retziuss*, Von Lenhossék®?, Arm-

stein®s and Jacques® have shown, by means of special pro-

cesses of nerve staining with chromate of silver and chloride

of gold, that the central prolongations of the gustatory cells

end bluntly in the tissue, and that the nerve fibrilli course

everywhere in close apposition to the cells, but do not com-

municate with them.

My own observations are entirely confirmatory of the

A STUDY OF THE ORGANSS OF TASTE. 161

conclusions of these later writers. The methylene blue was

found to be particularly selective in staining the gustative

cells, and their characters were well shown. The central

extremity usually ends bluntly at the base of the bud, but

may bifurcate, andthen end bluntly, or in an enlarged swollen

extremity (Fig. 2, Pl. III.) In nocase, after close scrutiny,

was there any long central process found, and never was

there any connection of this extremity with a nerve fiber.

The sustentacular cells did not stain with methylene blue so

readily'as ‘the. ‘sensory (Fig-/»3;. PI, IIT.) Thesershave san

enlargement usually at the terminations, which is single or

may divide into two or more short branches (Fig. 4a, PI.

III).

THE NERVE TERMINATIONS.

Previous authors have described the nerves as breaking up

into three systems of branches upon arriving atthe bud. The

perigemmal, those that surround the bulb; the intergemmal,

those that ramify between the bulbs; and the intragemmal,

those that enter the bulb itself.

Both the external and internal were carefully observed by

me, and their courses followed in many instances. In some

instances the silver method had stained these better and in

other instances the methylene blue was far better. In both

cases the selective staining of the most minute terminations

of the nerves was very satisfactory. To thus have, for com-

parison, the results of two entirely different methods of stain-

ing, both of which give the same conclusions, the one often

forming the complement of the other, is particularly gratifying

to the original investigator. Such two stains I found the

silver and the blue to be.

The fibrilli of the nerves were found to ramify and form

various networks, both externally and internally, but that the

external should be considered to follow two distinct courses,

as perigemmal and intergemmal fibers, seems superfluous, for

the intergemmal are but the perigemmal interpolated between

the buds.

162 A. E. LOVELAND:

The former are lost in the surface epithelium, probably

supplying the same, similarly to the perigemmal; they

terminate in the same manner and supply the same tissues.

Hence, they are probably portions of the same system (Fig.

64: P1AEEI):

The intragemmal fibers, on the contrary, enter the bulbs,

are placed in close apposition everywhere to the cells of the

buds, pursue various courses (Figs. 1 and 2, Pl. III.) and

either return upon themselves or end immediately in very

minute end swellings. In no case, however, did any fibers

connect with or join the extremities of any of the cells.

Jacques has given such an excellent description of these

fibrilli and their terminations, with all of which I agree, that

I will not enter into more detail, but referto Plate III.

SUBEPITHELIAL CELES.

The bipolar, sometimes multipolar cells, found by many

authors at the bases of the buds and the papillz, were shown

somewhat distinctly by the silver method, and more distinctly

by the methylene blue (Fig. 5, Pl. III.) These possess an

oval nucleus, and two opposite prolongations terminating

abruptly or branching, and where I was able to trace them,

seemed to be continuous with the nerve fiber (Fig. 1 6).

Jacques is inclined to think these are no other than nerve

cells, they resemble them so clearly. If so, the hypothesis

of Von Lenhossék, referred to before, would seem still more

probable, and in such case the cells must have been actually

left at the surface, though their connection with the central

nervous system has remained. What office these cells per-

form has been a matter of conjecture. It may be they are

connected with the function of taste, in the selection of cer-

tain elements for central interpretation, or it may be they

have nothing to do with taste, but are cells endowed with

some other function or property, possibly sensory, or possibly

trophic in nature. The hypothesis of Jacques, that they are

nerve cells intermediate in character between the bipolar

A STUDY OF THE ORGANS OF TASTE. 163

cells of the olfactory organ, and the nerve cells of the coch-

lear ganglion, must await verification.

In conclusion, every reason seems to point to the fact that

all the cells of the taste-buds perform no function except as

auxiliaries to the nerves in the impression of taste. Retzius

thus applies the name ‘‘secondary sensory” cells to them,

while Drasch considers the buds as a capillary system for

absorbing a solution, and bringing it in contact with the

nerves. That some selective action is carried on within the

bud has been shown by physiological tests, (Oehrwellss)

where quinine, sugar and succinic acid failed in but few cases

to be selected by one and the same papilla. That this selec-

tive action is done by the nerves is highly probable, in which

case the cells forming the bud have no more than a mechani-

cal part to perform.

Minot* calls attention to the uniformity in the specialisa-

tion of the sense-cells, in the organs of smell, sight, hearing

and taste, which at once suggests that they are all derived

from a common form. The similarity, he thinks, ‘‘ confirms

the theory that the special sense organs are modifications of

ganglionic sense organs, which, in the ancestors of vertebrates,

were all similar, and perhaps served a generalised function.”

From the above suggestion of Minot, together with the

selective action of methylene blue in staining the gustatory

cells in preference to the sustentacular, the conclusion might

be drawn that the former cells are entirely sensory in charac-

ter, as formerly believed, and epiblastic in origin, and that

the latter are mesoblastic or hypoblastic, and rightly judged

as supporting cells merely. Certainly such a conclusion is

worth consideration, and is not contrary to results already

obtained upon the development of the organs. Between

mesoblast and hypoblast for origin of the sustentacular cells,

the hypoblast seems to be more probably the true origin, as

was pointed out before in the discussion of the development.

* Human Embryology, 1892.

164 A. E. LOVELAND :

With our present knowledge, however, the conclusion

would seem to be that these cells act as ‘‘ secondary sen-

sory” cells. They may all be neuroblastic in origin, or only

the gustatory cells have that character, but from the relation

of both to the nerve endings they would seem to take the

part simply of auxiliaries or mechanical elements in the pro-

duction of the sensation of taste. They would thus bein the

same class with the auditory organ and the organs of touch.

It is the hope of the writer, that, since methylene blue has

now been shown to be so successful in nerve staining by

investigators generally, its use will be carried into many

other investigations, upon these organs, and so decide the

few points still unsettled concerning their function and gene-

tic relations.

The object of this paper has been to present the results of

previous investigations, together with such facts as my own

work has accomplished, in as brief a form as possible.

18.

Io.

A STUDY OF THE ORGANS OF TASTE. 165

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Instituto Lombardo, Vol. XX , 1887.

Hermann.—Studien iiber den feineren Bau der Geschmacksorgane.

Sitzungsh. d. math. physic. K. d. Akad. d. Wissensch., Munich.

Tuckerman.—Gustatory Organs of Vulpes Vulgaris. Jour. of Anat. and

Phys., Vol. XXILI., 1889.

—— —— Development of the Taste-Organs of Man. Jour. of Anat. and

Phys., Vol. XXIII., 1889.

——-—— The Gustatory Organs of Belideus Ariei. Jour of Anat. and

Phys., Vol. XXIV., 1889.

———— Further Observations on the Development of the Taste-Organs

of Man. Jour. of Anat. and Phys., Vol. XXIV., 1889.

—— Note on the papillz foliate and other taste areas of the pig.

Anat. Anzeiger III., 1888.

——— Anatomy of the papille foliate of the human infant. Jour. of

Anat., Vol. XXII., 1888.

—— —— Observations on the structure of the gustatory organs of the bat.

Jour. of Morph., 1888.

Hénigschmied. — Kleine Beitragen bemenend die Anordnung der

Geschmacksknospen bei den Saugerthieren, Zeitschrift fiir wissen-

schaftfl. Zool., Band XLVII., 1888.

Tuckerman.—Gustatory Organs of Procyon lotor. Jour. of Anat. and

Phys., Vol. XXIV., 1890.

On the gustatory organs of some Edentata. Internationale

Monatsschrift fiir Anat. and Phys., Bd. VII, 1890.

On the gustatory organs of some of the mammalia. Jour. of

Morphol., Vol. IV., 18go.

168 A STUDY OF THE ORGANS OF TASTE.

55:

56.

57:

58.

59.

60.

61.

62.

66.

67.

———— Observations on some mammalian taste-organs. Jour. of Anat.

and Phys., 1891.

Oehrwell.— Skandinavisches Archiv. fur Physiologie, 1890, Vol. II.

Hintze.—Ueber die Entwicklung der Zungenpapillen beim Menschen.

Strasburg, 1890.

Fusari et Panasci.—Sulle terminazioni nervose nella mucosa e nelle

ghiandole sierose della lingua dei mamiferi. Atti della R. Acad. delle

Sc di Torino T.XXV., 1890; et Arch. de Biol. ital., 1891.

Retzius.—Biologische Untersuchungen IV. Stockholm, 1892.

Gmelin.—Zur Morphologie der Papillze vallate und foliate. Archiv. f.

mikr. Anat. XL., 1892.

Niemack.—Der nervése Apparat. in den Endscheiben der Frosch-Zunge,

Anat. Hefte, 1892.

Shore.—Jour. of Phys., 1892, Vol. XIII.

Von Lenhossék.—Die Nervenendigungen in den Endknospen der Mund-

schleimhaut der Fische. Verhandl. der naturforsch. Gesellsch., Bd. X.,

Bale, 1892.

Der feinere Bau und die Nervenendigungen der Geschmacks-

knospen. Anatomischer Anzeiger. Janvier, 1893.

———— Die Geschmacksknospen in den Blattformigen papillen der

Kaninchenzunge. Verhandl. Phys. Med. Ges. Wurzburg, XXVII, 1893.

Arnstein.—Die Nervenendigungen in den Schmeckbechern der Sauger.

Arch. f. mikrosk. Anat., Bd. XLI., 1893.

Tuckerman —Development of the Organs of Taste. Reference Hand-

book of the Medical Sciences, IX., 1893.

Rauber.—Lehrbuch der Anatomie des Menschen. Bd. II., Abth. II.,

Leipzig, 1894.

Jacques.—Terminaisons nerveuses dans l’organe de la gustation. (Note

preliminaire. Bibliographie Anatomique, Novembre-Decembre, 1893.

Nagel.—Vergleighend physiologsche und anatomisch Untersuchungen

iiber den Geruchs und Geschmackssinn und ihre Organs mit einleiten-

den Betrachtungen aus der allgemein vergleichenden Sinnes-physio-

logie. Biblioth. Zool. Stuttgart, p. p. VIII., 1894.

LITERATURE UPON OTHER REGIONS THAN THE TONGUE.

Verson.—Beitrige zur Kenntniss des Kehlkopfs und der Trachea.

Sitzungberichte d. Wien. Akad. math-naturw. Kl., Bd. LVIL., I, 1868.

Davis.—Die Becherférmigen Organe des Kehlkopfes Archiv. f. mikrosk.

Anatomie, Bd. 14, 1877.

Foster.—Lehrb. d. Physiolog. deutsch v. Kleinenberg. Heidelberg,1881.

S. 493.

Exner.—Die Innervation des Kehlkopfs. Sitz-Ber. d. Wien. Akad,

math-naturw. KIl., Bd. LXXXIX., Wien., 1889.

Michelson.—Ueber das Vorhandensein von Geschmacksempfindungen im

Kehlkopf. Archiv. f. Path. Anatomie, Bd. 123, 1891.

170 A STUDY OF THE ORGANS OF TASTE.

PLATE 1.

Fig. I. Vertical section of epithelium of tongue of human fetus at stage

when the papillae are just beginning to form (tenth to twelfth week of fetal

life); a, columnar epithelium ; 4, polygonal intermediate epithelium ; ¢, flat-

tened surface epithelium ; d, cells of connective tissue of the mucosa.

Fig. 2. Vertical section through a fungiform papilla of a fetus about the

twelfth week ; a2, columnar epithelium ; 4, polygonal intermediate epithelium ;

c, flattened surface epithelium ; ¢@, cells of the connective tissue of the mucosa ;

¢,embryonic taste-bud, consisting of but few cells, and one-half subepithelial

in position. The papilla itself is only partially developed, the trench on one

side being filled with epithelial cells.

Fig. 3. Vertical section through a partially developed circumvallate

papilla of fetus of the twelfth to fourteenth week. The papilla is still on a

level with the epithelium, and the trenches or valleys on the side are closed.

Fig. 4. Vertical section through several foliate papilla of about the same

age as the preceding, showing their embryonic character, trenches still filled,

and no taste-buds; a, 4, c, a, same as above.

Fig. 5. Vertical section of circumvallate papilla of fetus of about the

fourth month, showing the valley well formed on the sides, and the taste-

buds further developed, and imbedded more deeply in the epithelium ; ¢,

taste-bud.

Fig. 6. Vertical section through a foliate papilla of fetus of about the

fourth month, showing trenches partially developed, and an embryonic taste-

bud partially concealed in the epithelium.

PEATE.

TNS

172 A STUDY -OF THE ORGANS OF TASTE.

PEATE AU.

Fig. 7. Vertical section through acircumvallate papilla of fetus of about

the fifth month of intrauterine life, showing the taste-buds entirely imbedded

in the superficial epithelium, and gravitating towards the sides and base of the

papilla. The papilla itself is well developed.

Fig. 8. Vertical section through the base and side of a circumvallate

papilla of fetus of about the sixth month, exhibiting only the lower portion of

the sides. Here the buds have become mature, very little different from the

adult, and occupy the base and sides of the papilla almost exclusively. Are

rarely found on top.

Fig. 9. Characteristic supporting or sustentacular cells of the taste-bulbs

of fetus near birth, the bulbs being well developed; 4, central end; a, peri-

pheral end.

Fig. 10. Characteristic sensory or gustatory cells of taste-bulbs of fetus

near birth, the bulbs being well developed ; 4, central end ; a, peripheral end.

PLATE II.

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174 A STUDY OF THE ORGANS OF TASTE.

PLATE Iil.

Fig. 1. Vertical section through a papilla foliata of the rabbit, showing

the distribution of the nerves to the surface and sides of the papilla ; a@, peri-

gemma! and intergemmal nerve fibrilli; 6, multipolar and bipolar cells of the

tissue, surrounding and at the base of the taste-buds ; c, gustatory cells of

the buds, the sustentacular cells not being stained ; d@, the chief nerve trunk

supplying the papilla, and branching to go to the buds.

Fig. 2. Vertical section through a taste-bud, where the gustatory cells

only are stained, together with the nerve fibrilli, and their relation to one

another is shown.

Fig. 3. Diagrammatic section through a taste-bud where the sustentacular

cells only are shown, and the distribution of the external nerve fibrilli (peri-

and intergemmal fibers of Jacques) in relation to these cells is represented.

Fig. 4. a, typical sustentacular cells as stained with methylene blue, show-

ing different manner of ending 1 and 2; 4, typical gustatory cells as stained

with methylene blue, showing the different manner of ending, 1 and 2.

Fig.5. Bipolar or multipolar cells found at the bases of the papilla and

the taste-buds, and usually connected with the nerve fibers

PLATE Ill.

Fig.l.

}

DEVELOPMENT OF METHODS IN MICROSCOPICAL

TECHNIQUE.

HENRY B. WARD, Pu. D., Lincotn, Nes.

It is my intention to discuss concisely the different ten-

dencies in methods of microscopical technique which have

developed in the course of the last century particularly and

which have served the purpose of those investigations that

are the basis of modern biological study.

The first and oldest tendency was that which viewed the

microscopé as an optical instrument together with the various

optical accessories capable of use withit. This is the oldest

and most varied direction of development and is, in reality,

nothing more or less than a branch of optical physics. In

spite of the long time which their development occupied, the

methods are really of comparatively limited application ; in

fact it may be said that a considerable percentage among the

biological workers of to-day possesses only a limited acquaint-

ance with the microscope from this point of view. Methods

of optical manipulation have fallen into disuse and the various

‘refinements in the way of optical accessories are not only

little employed in our biological laboratories, but are even

wanting in the equipments of some schools whose work stands

in the front rank. Many of the older workers in microscopy

have complained of this decadence, and a few of the younger

men have joined their voices in the criticism of present ten-

dencies, yet it may well be questioned whether this criticism

is just, and whether the actual value of optical manipulation

in the interpretation of biological problems is not very lim-

ited, and also equally doubtful.

176 HENRY B. WARD:

It would be unjust to overlook the fact that there are

workers with the microscope whose interest in problems is

not that of the biologist. From the nature of the subject,

however, from its distant yet direct relation to our own exist-

ence, from the abundance of living things which surround us

on every hand, and no less from the intensity of interest

which accompanies the manifestation of life, those students

who employ the microscope as an instrument in biological

investigation, whether it be that of the specialist, or of the

chance student of nature, always have and always will far

outnumber those who regard the microscope from all other

standpoints. It is for these, then, the students of living

things, and from their standpoint that microscopical methods

should be judged rather than from the standpoint of any much

more limited group of other students.

There always will be a few physicists whose studies will _

be largely devoted to the improvement of the optical qualities

of the instrument. Great advances have really been made in

the past few years by the studies of specialists inthis particu- -

lar line, and we may well look to the future for further

important advances in this respect, but the province of the

biologist hardly includes such questions. The microscope is

to him purely an instrument. He takes it in the shape in

which it is furnished to him, demands that it shall be capable

of performing the best work in the simplest manner, and

employs it as a valuable tool for the furtherance of his

researches. It seems to me that the failure of microscopic

study from the optical standpoint, simply, or even largely,

may be well illustrated bya single instance: The diatomists

are not even yet agreed as to the interpretation which shall

be placed upon a direct image, which is presented by the

microscope. Apparently under present conditions, the appli-

cation of purely physical methods to the solution of biologi-

cal problems has reached its limit. Other tendencies have

taken its place which have yielded fruitful results and the

future, it is clear, bids fair to accentuate further the tenden-

METHODS IN MICROSCOPICAL TECHNIQUE. 77

cies away from mere study of the instrument as an optical

combination.

The older microscopists, of whom I have been speaking,

took the objects of their study with little or no previous pre-

paration, except it was, in some cases, such as to remove the

living matter and leave test or skeleton in condition for

examination.

The first students of the more modern biological school,

on the other hand, were not content with this consideration

of mere dry bones, but bent their energies toward the more

careful study of the living matter itself. Here they came at

first face to face with one of the most characteristic features

of that living substance, its changeability, and watching from

moment to moment the modifications which arose in its con-

sistency, they were anxious not only to fix it in its actual

condition at a moment of time, that the details might be

more carefully examined, but further to render it transpar-

ent and thus get a glimpse of the processes which were being

carried on within it, processes altogether too dimly outlined

through the changing and commonly decidedly opaque sub-

stance of the living cell. Methods of killing and mounting

were indeed known, but now their reliability came to be

tested and the first question was, how accurately do they

present conditions which actually exist within the interior ?

and, secondly, how may the object thus reliably fixed be

further treated so as to present it in the condition most favor-

able for study? Along this line grew up graduaily, yet

withal rapidly, an extensive technique, which marks the

second tendency in methods of microscopical investigation.

Methods of hardening, fixing, staining and, most valuable of

all, of sectioning, have been evolved and tested by the most

crucial experiments which eager workers could devise, and

yet the advance here has not been simply an increase in the

number and kinds of methods. These processes have yielded

abundant fruit ; the wonderful researches of the last quarter

of a century have given an insight into biological problems

178 METHODS IN MICROSCOPICAL TECHNIQUE.

which has far surpassed the hopes of the most sanguine.

Problems of the cell, so intimately and fundamentally con-

nected with all biological science, are pressing towards their

solution under the assistance given by these methods. It is

also clear that we have by no means reached the limit of this

tendency in microscopical technique. Every month, almost

every week, brings new results attained by the modification

or more careful application of these methods and by the

introduction of new means of preparation.

To the student who examines carefully the course of the

past and the needs of the present, there is, however, at

least one direction in which future investigation is bound to

build a new road for itself and to advance along a new line.

The methods in vogue today for the examination and study

of living substance are but little improved over those which

obtained some thirty years ago; if possible we can see a

little more, it is because we have better lenses and better

instruments. The cell as a living thing, as regards the

changes which take place during its processes, is known by

inference from the dead object rather than by observations

upon its living substance. It is a chemical laboratory and

should be studied that we may know the reactions which are

taking place in it. If the methods of microscopical tech-

nique most generally in vogue at the present have given us,

as it were, a series of instantaneous photographs of the cell

and of the arrangement or rearrangement of its various parts

in various conditions, there yet remains to be developed that

technique which shall show us these substances in the process

of synthesis and analysis, that the investigator may be able

to follow the workings of the cell as a formative power and

come thus one step nearer the solution of the question, How

does living matter operate ?

NOTES ON THE ISOLATION OF THE TISSUE

ELEMENTS.

SIMON H. GAGE, Irnaca, N. Y.

In the present period when the technique of section cut-

ting has become so perfect that many of the cells of the body

may be cut into several pieces, there is some danger of losing

sight of the actual conformation of the cells as wholes. Cer-

tainly, as teachers of histology, it is desirable for us to show

our students as many of the cells or tissue elements as possi-

ble so that they may realise that the teacher is discussing,

real, tangible entities when he speaks of epithelial cells, muscle

cells or brain cells, and the like. Furthermore, the student

should gain an allround conception, so to speak, and this notion

of the tissue elements is gained by the student only when he

can see all around the structures ; this feat is easily accom-

plished in the isolated cells by causing them to roll over with

a little pressure on the cover-glass.

In dissociating, the aim is to separate the tissue elements

from one another, the cells and all their minute processes

being preserved in theirtrue form. In order to do this the

cell-cement, or intercellular substance, must be dissolved or

softened. The perfect dissociator then, must harden the

tissue elements and soften the substance which holds them

together. Many excellent dissociators have been described.

None will serve equally well for all tissues, and there may be

a ‘‘best dissociator” for each animal ; it seemed worth while,

however, to present a note upon the results of an extended

series of experiments to discover if possible the general and

underlying principles.

180 SIMON H. GAGE:

The general principles seem to be these: Any agent

which acts asa good hardening and fixing medium for a tissue

well also serve for a datssoctating substance tf sufficiently

diluted and allowed to act only a short time. So far as

experiments have gone it was found that if the fixer suitable

for a tissue were diluted ten times and allowed to act from

two hours to two days, good results were obtained in isolating.

It was further found that if the diluting substance used were

normal salt solution (water 1000 cc., common salt 6 grams, )

the results were, perhaps, more satisfactory. This use of

normal salt solution was suggested from the fact that it tends

to leave the tissues without change, and the diffusion cur-

rents are not so severe as when water alone is used for

dilution.

For the epithelia of mucous and serous surfaces nothing

was found so satisfactory for all animals as formaldehyde in

normal salt solution. The strength used was 2 cc. in a liter

of normal salt solution. For many epithelia the isolation

may be considered sufficient in one to two hours ; good pre-

parations from the same may be got after adayortwo. This

dissociator is excellent for obtaining the ciliated cells of the

brain ventricles. And in experimenting with it for that pur-

pose it was found that the nerve cells of the cerebral cortex

were most satisfactorily isolated also. For one who hasonly

seen nerve cells in sections it would be a revelation tosee the

processes as shown in such isolation preparations, and then

if the cells be made to roll over, it will be seen that the cells

have processes projecting from every side.

No method of studying the isolated elements has been so

successful as scraping off a small mass and mounting on a

slide in the dissociating medium, and then for the more com-

plete separation the cover-glass is gently hammered over the

mass of cells. The mechanical jarring separates the cells

without tearing them, and often two or more cells are just

sufficiently separated to show their mutual relation. It is

sometimes advantageous to add a little eosin solution to the

ISOLATION OF THE TISSUE ELEMENTS. 181.

mass of cells before mounting or after, but as the mounting

medium, if the dissociator is used, is of such different refrac-

tive index, all the structural details come out without stains;

and it is worth while to let the student see that histological

structure can be seen under the microscope without gorgeous

stains. He will then know, which I fear is not always the

case now, that the cells are not red and purple in the living

body.

If in examining preparations mounted only in the disso-

ciator one should meet with something that he was extremely

desirous of preserving, the slide may be laid flat and a drop

of glycerin put at the edge of the cover. It will partly diffuse

and also as the dissociator evaporates it will run in by capil-

larity and in a few days the preparation will be mounted in

glycerin. It may then be sealed with shellac or other cement

and will last a reasonable length of time, that is, till one

naturally gets a better preparation to take its place.

If one wishes to have the cells stained for the permanent

preparations, instead of using glycerin alone, as just described,

the following mixture will be found excellent: Glycerin,

85 c.c.; alum carmine, 73 c.c.; eosin, 3} per cent. aqueous

solution, 7}. c.c. This may be put at the edge of the cover

as for the glycerin, or preferably it should be mixed with

the cells before putting on the cover-glass. The alum

carmine stains the nuclei and the eosin the cell body.

DAHLIA AS A STAIN FOR BACTERIA IN SECTIONS

CUT BY THE COLLODION METHOD.

RAYMOND C. REED, Pu. B., Irwaca, N. Y.

Many elaborate methods of staining bacteria in tissues have

been devised, but with nearly all of them difficulties have been

encountered. Probably the greatest trouble has been in the

staining of the imbedding medium or the albumen fixative

which usually obscure both the tissue elements and the bacte-

ria. Unless, therefore, the sections are cut in paraffin and

not fastened to the slide by these common fixatives the bac-

teria are not satisfactorily brought out. Here again arises

another obstacle. With loose or fragile tissues there is great

danger of tearing the sections or of losing parts of them dur-

ing the process of staining and dehydrating, thus destroy-

ing the value of the preparation.

Although paraffin is commonly used in pathological his-

tology, collodion is more often employed in imbedding normal

tissues. The rule in normal histology is to fasten the sec-

tions to the slide. In pathological histology they are not,

for the reasons mentioned, ordinarily fastened, but in many

cases it seems better to do so. The need of having an abso-

lutely perfect section from a pathological tissue, especially

for diagnosis, is even greater than is the case when sections

of normal tissues are being made. The loss of a very small

bit from the section may cause an entirely erroneous inter-

pretation. By the use of collodion as the imbedding medium

this danger is practically entirely eliminated, while the

method is much simpler and easier than that in which paraffin

is used and the sections are fastened to the slide by the use

of collodion or an albumen fixative.

DAHLIA AS A STAIN FOR BACTERIA. 183

It is a well known fact that collodion takes most of the

aniline dyes and will not give up the stain without being

treated with a decolorising agent sufficiently strong to

decolorise the tissue at the same time. Inthe case of paraffin

sections which have been fastened-to the slide with collodion

or albumen fixative, or both, besides the disadvantage of using

a process which takes a longer time, we meet the same diffi-

culty that we did in the collodion method, in that the fixative

takes the stain and obscures the preparation quite as muchas

does the imbedding collodion.

Both the collodion and the paraffin methods have their

advantages for special kinds of work. Ordinarily in patho-

logical histology I much prefer, for the reasons mentioned,

collodion to paraffin as an imbedding medium. The method

I have used is that described by Prof. S. H. Gage* in a paper

read before this society in 1895. In it he summarised the

whole process of sectioning by the oil-collodion method and

suggested two very important improvements in the way of

simplifying and cheapening the process. This method

includes the improvements suggested by Dr. P. A. Fish’ in

1893. Dr. Fish fastened the sections to the slide by putting

a few drops of ether and alcohol on the section after it was in

position. Prof. Gage used a mixture of three parts of xylene

and one partof castor oil as a clarifier. In passing a section

from water to strong alcohol, or vice versa, he avoids the

diffusion currents by plunging the slide directly into the

desired liquid instead of carrying it through successively

higher or lower percentages of alcohol, as the case might be.

This method, as perfected by Dr. Fish and Prof. Gage, is

very simple and apparently the best one yet devised.

After finding the best method of cutting the sections the

problem then seems to resolve itself into the selecting of a

suitable dye that will stain the bacteria properly and yet one

* S.H. Gage, Improvements in Oil-Sectioning with Collodion. Proceedings American

Microscopical Society, Vol. XVII., 1895, pp. 361-370.

+ P.A. Fish, A new Clearer for Collodionised Objects. Proceedings American Micro-

scopica] Society, Vol. XV., 1893, pp. 68-89

184 RAYMOND C. REED:

that will wash out of the imbedding material without the use

of a decolorising agent so strong that it will remove the stain

from the tissue and the bacteria.

During the past year we have had a large amount of patho-

logical material to section and for the most part for diag-

nosis. At first I cut most of this in paraffin, as Dr. Moore

preferred it to collodion on account of the staining of the

collodion. Inthe winter term I had some sections that I

wanted to stain with gentian violet, but finding that we were

out of it, I substituted dahlia in its place. These sections

had been cut by the paraffin method and it was found that

the stain not only showed the bacteria well but also brought

out beautifully the histological structure of the tissue. Later

I had occasion to cut some sections from some material

which had been imbedded in collodion and to stain them for

bacteria. After using other stains, such as carbol fuchsin and

methyl violet, with unsatisfactory results, I tried an aqueous

solution of the dahlia and found that it worked perfectly. In

the process of washing and dehydrating this was entirely

removed from the collodion, leaving both the tissues and the

bacteria well stained and sharply differentiated.

Other formule, using dahlia as the dye, were tried, such

as a solution containing less of the elements of a mordant

nature, using 2 per cent. carbolic acid instead of 5 per

cent., and also Koch-Ehrlich’s aniline water solution. The

carbolic acid solution did fairly well, but the aniline water

solution stained the collodion too deeply and permanently.

Neither brought out the cellular elements with anything like

the clearness that the simple aqueous solution did.

The formula for the stain used is as follows :

Saturated alcoholic solution of dahlia ..... 20,.65C>

Distilled swatervc. ih ses, seeds aoe poe ee 1oo cc.

The length of time necessary to stain properly varies,

according to the condition of the tissue, from fifteen minutes

to half an hour, that is, they must be distinctly overstained.

DAHLIA AS A STAIN FOR BACTERIA. 185

Then wash thoroughly with 95 per cent. alcohol until the

collodion around the section appears colorless, and clear with

a clearing fluid, preferably clove oil. The tissue will be well

defined and the bacteria will stand out deeply stained against

the more lightly stained cells of the tissue.

Of course,this method will not do with certain bacteria that

require special stains or treatment, but it does work most

admirably with the majority of microorganisms found in

diseased animal tissues.

THE HEMOSPAST.

A NEW AND CONVENIENT INSTRUMENT FOR DRAWING

BLOOD FOR MICROSCOPIC EXAMINATION.

VERANUS A. MOORE, M. D., Irnaca, N. Y.

In a recent number of the Wedzcal Record 1 called atten-

tion to this instrument as a convenient apparatus for physi-

cians in drawing small quantities of blood for diagnostic pur-

poses. During the past few weeks, however, I have made

some important changes in its construction, and which are

incorporated in the present description. The constantly

increasing attention which is being given to the blood, and

the importance of the results of its examination in making

diagnoses, renders improvement in the instruments for obtain-

ing even the little blood needed for this purpose worthy of

attention. Although a sharp pointed bistoury, a surgical or

even sewing needle can be used by the vigorous laboratory

student on himself or equally robust companion with little or

no discomfort, this little operation has a much more serious

aspect to the anemic and usually nervous patient. With

these the mere sight of a sharp instrument, although it be

but a surgical needle, causes much apprehension. It fre-

quently happens that in the very anemic it is necessary to

make several ‘‘stabs” before a sufficient flow of blood is

secured, and often through a desire to avoid a repetition of

the hurt I have seen unnecessarily deep incisions made.

In studying the blood of the smaller or experimental ani-

mals in the laboratory the task of getting the blood is less

difficult, but even here the incision which is made with a

THE HEMOSPAST. 187

scalpel, bistoury, or scissors is often unnecessarily long or

deep. For the larger animals the spring fleam is very satis-

factory, but it is not applicable for the smaller species or for

the human subject.

The introduction of the hematocrit for the determination

of the number of red blood corpuscles necessitates a slightly

larger quantity of blood for each examination than was

required for the counting apparatus and consequently aggra-

vates the difficulties, by the present methods, of procuring

the required amount. The desire for an instrument with

which the incision could be made instantly, and the depth of

the cut accurately regulated, led me to make some experi-

ments in the construction of an apparatus possessed of these

qualities. The outcome has been aspring needle lancet which

works so admirably, and which has so completely removed

the difficulties mentioned that it seems worthy of description.

The hemospast’ consists of a metal tube (I have used

brass) about five centimeters long and one centimeter in diam-

eter. The upperend is closed with a milled-edged screw-cap

and the lower end covered with a perforated screw-cap, upon

which is a second perforated screw-cap about one centimeter

long. This forms a regulator for graduating the length of the

projection of the cutting needle. A narrow longitudinal slot,

two centimeters long, is cut in one side of the tube, begin-

ning one-half centimeter from the lower end. This has a

shallow notch cut into the tubing at the top and a deep pock-

eted one a little below the middle. In the upper part of the

tube is a piece of coiled wire spring two and a half centime-

ters long and of sufficient strength to give the necessary

force to acylindrical plunger carrying the needle, which is

1 Hemospast is the noun from the Greek combination of which the adjective form

hemospastic (drawing or attracting biood) is already in use.

188 THE HEMOSPAST.

placed next to it in the lower part of the tube. The plunger

rests against the cap. The incision is made with a triangu-

lar-pointed needle inserted and fastened into the lower end

of the plunger. A piece of perforated rubber covers the

lower end of the plunger and prevents the harsh clicking

sound which otherwise would follow the springing of the

needle. From the side of the plunger projects a trigger

which moves in the slot and with which the plunger is pushed

up. When the spring is thus set the trigger is easily caught

by a slight twisting movement into the notch at the upper

end of the slot. When not in use, the trigger rests in the

pocketed notch. By means of the regulator the length of

the projecting part of the needle can be easily adjusted. The

needle is entirely hidden from sight, so that the instrument,

if exposed to view, does not suggest an implement of torture.

In use it is convenient and easily handled. After the

finger, or other part, is cleansed and the incision is to be

made the spring is set and the instrument is pressed gently

to the part, the trigger pushed slightly and the incision of

exactly the depth desired is instantly made. As soon as

sprung the hemospast can be dropped and the collection of

blood begun.

This instrument is equally efficient and much more conve-

nient in procuring small quantities of blood from experimen-

tal animals than those whichI have heretofore observed in the

hands of others or employed myself. As it is made entirely

of metal it can be sterilised as other surgical instruments. If

desired, it can be made larger and stronger with needles of

various sizes and, if preferred, with a cutting edge of a milli-

meter or more in length. It is available, therefore, for work-

ers in laboratories where normal human blood or that of

healthy or diseased animals is being studied, as well as for

the practising physician. Although simple in its design,

there were a few mechanical difficulties encountered, for the

overcoming of which I am indebted to Mr. W. C. Barnard

for timely suggestions.

TWO VERY SIMPLE MICROTOMES.

EDWARD PENNOCK, PHILaApEcpaia, Pa.

Nothing especially novel in principle is claimed for these

instruments, but it is believed that they are worthy of your

attention as putting into convenient and commercial shape

well-known and useful principles at the lowest cost. Itis the

writer's experience that the high cost of nearly all aids to sec-

tion-cutting deters very many students from obtaining them.

Such need not be the case with these, which hardly, indeed,

rise to the dignity of instruments of precision, but which will

doubtless be found a real aid to good work.

First—The ‘‘Handy” has a V-shaped groove for the

paraffin-imbedded or the naturally hard object, the latter

being moved forward by a finely cut screw, the object being

held in place by the thumb; there is a flat expansion at the

end for the razor, which should preferably be flat-ground,

though the ordinary shaving razor will do good work, espe-

cially if it is not what is known as full concave ground.

(See illustration, Fig. 1.)

Second—Dr. Wetherill’s application of the well-known

rivet principle to a hand microtome. It is made of hard

wood, with a horizontal portion as a guide for the sweep of

the razor and an incline upon which slides the rider or object-

carrier, to which the paraffin-imbedded object is attached by

melting. That is all. In the case of a naturally firm object

the rider may, indeed, be dispensed with; in either case the

object is moved up the incline by the thumb of the hand

holding the microtome. oS illustration, Fig. 2.)

BY Soe Se TT

End Section. Elevation.

Fig. 2.

PRO CE EDT Ness

The American Microscopical Society.

MINUTES OF THE TWENTIETH ANNUAL MEETING

HELD AT

TOLEDO, OHIO, AUGUST 5,. 6, 7, 1897.

THURSDAY, August 5, 1897.

The members assembled in the auditorium of the Central

High School at 2.30 P. M. and were called to order by the

President of the Toledo Microscopical Society. Mayor Jones,

of Toledo, was then introduced and in a few well-chosen

words welcomed the members to the city. Although not a

microscopist, yet he appreciated the great advances made in

science by the use of the microscope and predicted still

greater results in the future.

Professor E. W. Claypole, president of the society, replied

to the words of welcome and declared the twentieth annual

meeting open for the transaction of business.

The names of a number of new members were then read

as recommended by the Executive Committee, and by reso-

lution the secretary cast a ballot of the society for them and

declared them elected. Their names will be found in the list

of members at the end of the volume.

The president appointed as an auditing committee to

examine the accounts of the treasurer Dr. A. Clifford Mer-

cer, J. C. Smith and F. W: Kuhne.

AMERICAN MICROSCOPICAL SOCIETY. Igt

The society proceeded to the election of the nominating

committee, and the following members were declared elected:

Magnus Pflaum, Dr. A. Clifford Mercer, Dr. William C.

Krauss, Miss Edith J. Claypole and Dr. D. E. Hoag.

The first paper to be presented was read by Magnus Pflaum,

of Pittsburg, Pa., on The Microscope as a Factor of Civilisa-

tion. Discussed by Professor D. S. Kellicott.

In the absence of Professor S. H. Gage, of Ithaca, N. Y.,

his paper on Notes on the Isolation of the Tissue Elements

was read by the secretary. The discussion was participated

in by Professor Kellicott, Dr. Mercer, Dr. Krauss, Miss

Agnes Claypole and Mr. Pflaum.

The secretary also ‘read the paper of Mr. John M. Berry,

of Peterboro, N. Y., on Comparison of the Phagocytic Action

of Leucocytes in Amphibians and Mammals. Discussed by

Miss E. J. Claypole, Professor Kellicott and Dr. C. S. Miller.

Thursday evening, at 8 o'clock, the society and friends

assembled at the High School to listen to the address of the

president, Professor E. W. Claypole, of Akron, Ohio, on

Microscopical Light in Geological Darkness. Following the

address an informal reception was held, participated in by

the members of the society and the Toledo Microscopical

Society.

FRIDAY, August 6, 1897.

Meeting called to order at 10 o'clock. Professor D. S.

Kellicott, of Columbus, Ohio, read papers on Capture and

Study of Rotifers and Rotifera of Sandusky Bay.

Mr. J. C. Smith, of New Orleans, La., read papers on

Notes on Some Undescribed Infusorians from Louisiana and

The Sporular Development of Ameba villosa, Leidy.

Mr. Francis Scott Rice, of Steelton, Pa., then read a

paper on The Micro-structural Characteristics of Steel, with

lantern slide demonstrations.

192 PROCEEDINGS, GE DHE

Friday afternoon the society, as the guest of the Toledo

Microscopical Society, spent a few hours on an excursion on

the Maumee River and Lake Erie, much to the enjoyment

and contentment of the members present.

Friday evening, at 8 o'clock, the society, in conjunction

with the local society, gave a microscopical exhibition at the

Public Library to the citizens of Toledo. The exhibition was

a success in every way and was a source of much pleasure

and astonishment to those unacquainted with the revelations

of the microscope.

SATURDAY, August 7, 1897.

Meeting called to order by the president at 10.15 o'clock.

The nominating committee reported as follows:

Officers of the society for 1897-98: President, Professor

D. S. Kellicott, Columbus, O. ; vice-presidents, Dr. Moses

C. White, New Haven, Conn.; Dr. Veranus A. Moore,

Ithaca, N. Y.; secretary, Dr. William C. Krauss)’ Buffales

N. Y.; treasurer, Magnus Pflaum, Pittsburg, Pa.; executive

committee, Dr. D. E. Hoag, Toledo, O.; Dr. Robert Aber-

dein, Syracuse, N. Y.; Miss Edith J. Claypole, Wellesley,

Mass.

Upon motion the secretary was directed to cast a ballot

for the nominees as reported by the committee and they

were duly elected.

The treasurer's report was read and accepted.

The report of the auditing committee was read and

adopted.

Miss Agnes M. Claypole, of Wellesley, Mass., then read

a paper on Forms of Cleavage in the Eggs of Certain Arthro-

pods.

Miss Edith J. Claypole, of Wellesley, Mass., read a paper

on Comparative Structures of the Digestive Tract.

AMERICAN MICROSCOPICAL SOCIETY, 193

Owing to lack of time, the discussion on the Microscope

in the Hands of the Teacher and the Physician was omitted.

The following’ papers’ were read by title: The First

Deposit of Bacillaria Diatoms Discovered in America, A. M.

Edwards, M. D., Newark, N. J.; Two Very Simple Micro-

tomes, Edward Pennock, Philadelphia, Pa.; Varieties of the

Favus Fungus, Frank J. Thornbury, Buffalo, N. Y.; Methods

in Microscopical Technique, Professor H. B. Ward, Lin-

coln, Neb.; Bacteriology of Puerperal Convulsions, Dr. A. M.

Veeder, Lyons, N. Y.; Dahlia as a Stain for Bacteria in Sec-

tions Cut by the Collodion Method, R. C. Reed, Ithaca, N. Y.;

The Hemospast, a new and convenient instrument for

drawing blood for microscopical examinations, V. A. Moore,

Ithaca, N. Y.; A Study of the Organs of Taste, A. E. Love-

land, M. D., New Haven, Conn.; A Comparative Study of

Hair from the Medico-legal Aspect, W. G. Reynolds, B. A.,

M. D., Watertown, Conn.

A vote of thanks was tendered the Toledo Microscopical

Society for the entertainment during the session and a vote

of thanks was given the retiring president, Prcfessor E. W.

Claypole, after which the society adjourned.

194 ° PROCEEDINGS OF THE

TREASURER’S REPORT.

FOR YEAR ENDING JULY 22, 1897.

Dr.

To Balance on hand, Pittsburg meeting ...... $ 25.00

** Membership di E894; kes Tt ae SPs $ 2.00

ss &e TSO GS ee ese ec eiernonces Inte 4.00

» as £8 eh TROQOS TOs eres us eee sacs ope ate 20.00

oe “ SPITS O Te PEI E Wom rie aia gee Rens 447.00

és 6 Coon) ESO Sib Erica Ve ae eRe LAS creas aes 10 00

483 00

‘S¥Admission fees; 18075935) eek oaaoe seas Leite ees 99.00

&s <¢ SAIS 250s )al GV ee SN He ee oat SLE ATA ta 3.00

——— 102.00

‘Se Subseriberss iu a eee ‘ EOS om nOs BORO. : 18.00

“Donations, bd. Pennock: i--m aan cme wears Pate & 7.75

+ “¢ by authors for plates 4/0. 21 eon 116.80

SSS 124.55

“ Sale of ee cial te tats attyieas hs saliis: lie. ey sac CSR Pace : 95.92

‘“* Postage and expressage colicsieds: Bae MSM ERS Rea R a No aos 1.99

$994.96

Cr.

By expense of Pittsburg meeting ......... $ 37.50

see HOSLABEN so saris. bier Sac Syn ce enpieeaee 22.55

ey NEUXPLessage.. s\uttst sc. mh oeabigne eas amen alae ne ae < 45.30

< stationery, and printing) i) ett liek eo ciae aye 24.65

8. SUNGTICS) .2s) shane eee IO La een ee et : 25.20

Issuing’ Volo XWVAIL,; balance: gave. oho) sca eee 100.00

Sheets <> XV LTT printing eee i e145 0.00

es os Os plates) 070, em annoy els

etrice, 723-15

Balance‘oniiand =. hag hye so cane YOM Poe : 16.61

—— $994.96

AMERICAN MICROSCOPICAL SOCIETY. 195

SPENCER-TOLLES FUND.

Amount reported at Pittsburg meeting ............. $ 42304

aitenestereceived:to™ Januanye®.p£SQ7/1-) Ith evts oe gel aves) sb sso * 24.42

cS fou uly a; S67) (>a geben ees EANornc us are 21.57

$469.03

otalnincrease during thesyear... io2 cys specu ee lene 2 ie 8 ee 45.99

MAGNUS PFLAUM,

Treasurer.

We hereby certify that we have examined the foregoing accounts for the

year 1896-1897 and find the same correct, with proper vouchers for expendi-

tures.

F. W. KUHNE.

J. C. SMITH.

A. CLIFFORD MERCER.

August 5, 1897.

CONSTITUTION.

ADOPTED AT ROCHESTER, N. Y., 1892.

AR RICEL EA

This Association shall be called the AMERICAN MICRO-

SCOPICAL SOCIETY. Its object shall be the encouragement

of microscopical research.

ARTICLE II.

Any person. interested in microscopical science may

become a member of this Society upon written application

and recommendation by two members and election by the

Executive Committee. Honorary members may also be

elected by the Society on nomination by the Executive

Committee.

ARTICUESIIE.

The officers of this Society shall consist of a President and

two Vice-Presidents, who shall hold their office for one year,

and shall be ineligible for re-election for two years after the

expiration of their terms of office, together with a Secretary

and Treasurer, who shall be elected for three years and be

eligible for re-election.

ARTICLE’ IV.

The duties of the officers shall be the same as are usual in

similar organizations ; in addition to which it shall be the

CONSTITUTION. 197

duty of the President to deliver an address during the meet-

ing at which he presides; of the Treasurer to act as custo-

dian of the property of the Society, and of the Secretary to

edit and publish the Proceedings of the Society.

ARTICLE V.

There shall be an Executive Committee, consisting of the

officers of the Society, three members elected by the Society,

and the past Presidents of the Society and of the American

Society of Microscopists. :

ARTICLE V I;

It shall be the duty of the Executive Committee to fix the

time and place of meeting and manage the general affairs of

the Society.

ARTICLE. “WIT.

The initiation fee shall be $3.00, and the dues shall be

$2.00 annually, payable in advance.

ARTICLE VIII.

The election of officers shall be by ballot.

ARTICLE FX.

Amendments to the Constitution may be made by a two-

thirds vote of all members present at any annual meeting,

after having been proposed at the preceding annual meeting.

BY-LAWS.

The Executive Committee shall, before the close of the

annual meeting for which they are elected, examine the

papers presented and decide upon their publication or other-

wise disposal of them.

All papers accepted for publication must be completed by

the authors and placed in the hands of the Secretary by

October Ist succeeding the meeting.

The Secretary shall edit and publish the papers accepted,

with the necessary illustrations.

TT:

The number of copies of Proceedings of any meeting shall

be decided at that meeting.

iV.

No applicant shall be considered a member until he has

paid his dues. Any member failing to pay his dues for two

consecutive years, and after two written notifications from

the Treasurer, shall be dropped from the roll, with the privi-

lege of re-instatement at any time on payment of all arrears.

The Proceedings shall not be sent to any member whose dues

are unpaid.

The election of officers shall be held on the morning of

the last day of the annual meeting. Their term of office

shall commence at the close of the meeting at which they, are

elected, and shall continue until their successors are elected

and qualified.

BY-LAWS. 199

VI.

' Candidates for office shall be nominated by a committee

of five members of the Society.- This committee shall be

elected by a plurality vote, by ballot, after free nomination,

on the second day of the annual meeting.

VII.

All motions or resolutions relating to the business of the

Society shall be referred for consideration to the Executive

Committee before discussion and final action by the Society.

VITE

Members of the Society shall havethe privilege of enroll-

ing members of their families (except men over twenty-one

years of age) for any meeting on payment of one-half the

annual subscription ($1.00).

Approved by the Society, August 11, 1892.

LIST OF MEMBERS.

The figures denote the year of the member’s election, except ’78, which marks an original

member. The TRANSACTIONS are not sent to members in arrears, and two years’ arrearage:

forfeits membership. (See Article IV. of By-Laws.)

' Members Elected at Toledo, 0., 1897.

For addresses see regular list.

BEARDSLEY, A. E. : MAsTERMAN, ELMER E.

Berry, JoHN McWILLIaMS Myers, Burton D.

Hasencamp,,Oscar, M. D.- ~~ _ Piwonxa, F., Esg. "ir

HERTZLER, ARTHUR A,, M. D,, ~ REED, RAYMOND C..

JOHNSTON, Levi D., M. D. oe ns REYNOLDS, WILLIAM GEORGE, M. D

Kine, A. T. SMITH, J: C.

Loomis, CHANDLER H.

LOVELAND, A. E.

SNYDER, JAMES B.

Woopwarp, A. L.

ABERDEIN, RoBErT, M. D., F. R. M.S., '82, . . 327 James St, Syracuse, N. Y-

AckER, Gro. N., M.D.,’9I1,. - . 913 Sixteenth St., N. W., Washington, D. C-

AINSLIE, CHARLES N., ’92, . Se Beg estes . Rochester, Minn.

ALLEGER, WALTER W., M. D.,'94, - - 9068S. St., N. W., Washington, D. C-

Atwoon, E..S:,.°70,)s <2. oo bossa yao) ee ee 5 2ON W. 34theS be ivicyvanieeanias

Arwoop, H..F., F.'R: M:S., 778,37". 0. 3 3. el. 2 a. 2s Rechester mame

AvEers, MorGan W., M. D., 87, .°. . “.. . . . . Upper Mont/Glair a

Bai, MICHAEL VALENTINE, '93, - - . - - 1132 Spruce St., Philadelphia, Pa-

BarkKER, ALBERT S., 97, ... . . - 24th and Locust Sts., Philadelphia, Pa.

BARNSFATHER, JAMES, M. D., ’gI,

Cor. Fairfield Ave. and Walnut St., Dayton, Ky.

Barr; Prof: Cuas: E590". <5 So cies. cess es Albion Gollege; Albion, Mich.

BARTLETT, CHARLES JOSEPH, M. D., '96,. . . . . . . - . New Haven, Conn.

Bauscu, Epwarp,'78,. ..... .. -179 N. St. Paul St., Rochester, N-v=

Bauscu; HEnry, 786, . 2 6 3 Sob es ee a eee ee RR OG BIES tere

THE AMERICAN. MICROSCOPICAL SOCIETY. 201

eae Prot. JAMES HARTLEY, (96, S00.) 5 Aa ay See ss SCI; Ohio.

FROME DSISR VAN AW Enoki Oy tains, bre Mielke § 2a Gayigaba eit aie os Mais . -» . Greeley, Col.

eee CLARK ESO:, 92, atte. se. SOR D Beata New York City.

BENNETT, HENRY C ,’93,-. - . 5 «= « . 250 W. 42d St.,.New ‘York Gity..

Bisco, Prof. Tuomas D., ae i ee . » 404 Boat St., Marietta, Ohio.

BieiLe, A. M.,M.D.,’'81, . . . . . Ohio State University, Columbus, Ohio.

BoprnE, Prof. MONKTON! 96, ah cea . . . Crawfordsville, Ind.

Booty, Mary A., F. R.M.S., ‘82, . . 2. . 32 Byers St., Springfield, Mass.

Boyce, JAMEs C., Esq.,’86,. . . .. . . . Carnegie Building, Pittsburg, Pa.

BOGE. JOHN We, Mis Ds 106) 0 or 2 oie . . 23 Mawhinney St., Pittsburg, Pa.

ROVER Gay eA Ms O2) ans). 2. oa. 2 g22eN@lifford).st., Philadelphia, Pa.

Bray, Tos. J., 96, . .. 1... . Trenton Ave., 23d Wd., Pittsburg, Pa.

BrepIn, Geo S., ‘96, Re hee? sAgeitsdyeukel Beier tists: Oil Ciby,.Par

BrRoMLEY, Ropert Innis, M.D., 93; .... . ie ese, 2° Sonora Cals

Brown, Miss L. Se LOD te a Btn tT. yo EMV EI MAIN Obs, Ani Celica ING Yy.

Brown, N. HowLanp,’9Il, . .-. ... . . »« 33 S. 10th St., Philadelphia, Pa.

Brown, Rosert, '85, . . . 4. . . Observatory Place, New Haven, Conn.

BRUNDAGE, ASH M2 Ds, 94, —2 vos. . . 1153 Gates Ave., Brooklyn, N. Y.

BuLtL, James Epaar, Esg.,’92,. . . . . 253 Broadway, New York City, N. Y.

Burner, Natuan L., M. D., 96, . . . . 368 Hamilton Ave., Columbus, Ohio.

Burt, Prof: Epwarp A.,’9I, ... . Middlebury College, Middlebury, Vt.

BuscuH, FREDERICK Cart, M. D., ’95,. . . 179 Richmond Ave., Buffalo, N. Y.

Busu, Bertua E., M: D.,’'95,. . . . . . - 808 Morse Ave., Rogers Park, IIl.

CAMPBELL, D. P., M. D., ’88, . Tomichi, White Pine P. O , Gunnison Co., Col.

CARPENDER, Eros) BY, MDs; 96," 2... 2. = - 325 Jersey St., Buffalo, N. Y.

CarRTER, JoHuN E., ’86, ee . Germantown, Philadelphia, Pa.

CHESTER, ALBERT H., A.M ,’88,. . Rutgers Collége, New Brunswick, N. J

Capp, GEo. H , '86, 24: ss as . 196 Water St), Pittsburg, Pa.

Crark, GayLorp P., M. D., ‘96, By ane ah -tiite a. Syracuse, Ney

CLARK, GEORGE Epw., M. D.,’96, .. . . seianeeree Onondaga Co., N- Y.

CLAYPOLE, AGNES M., ’94,..... . . . Wellesley College, Wellesley, Mass.

CLAYPOLE, EpiITH JANE, Ph.B, MS, ’93, . Wellesley College, Wellesley, Mass.

CLAYPOLE, EDwarRD W., B. Sc, F.G.S.,’86, .. Wes, » MAKEOND,. OBIO;

GaEEe SHAS IN, WALEMS, (OOM tee 4. ce ve ale ae N. Pine St., Albany, N. Y.

CONSER, Harry NEwToN, 95, ..... -. - - Lock Box 657, Sunbury, Pa.

Coon, H. C:, A. M.,M.D., '82,: ... .. . Alfred University, Alfred, N. Y.

MOORE ATER: Wa ).5: SO, te) psn ane rr esl ose ses ov LAI OYCamore ots; OiliGity;sba,

Coucn, Francis G., '86,

Kalish Pharmacy, 23d St. and 4th Ave., New York City.

Cox, Cuas. F., FR: M.S.,’85,. . . . Grand Central Depot, New York City.

CraiG, CHARLES Francis, M.D.,’94,. . . . 301 Main Street, Danbury, Conn.

CralG, THOMAS, 93, - ..... . - . 244 Greenpoint Ave., Brooklyn, N. Y.

CUNNINGHAM, M.C.,’96,..: .... . . . . « Board of Health, Pittsburg, Pa.

202 . THE AMERICAN MICROSCOPICAL SOCIETY,

Davis, W. Z., '86, . Suck hysteria faith Mane aa: . Marion, Ohio.

Dean, N. B.H, M. D., ZOO ur yc Rea eke nae caee aie St., Brighton, Ont.

DEFENDORF, ALLEN Boas Mid 596) ye seen ues . Worcester, Mass.

DESH EAE RE DM Ger Mich Deni Ose vat hous icin eme ne 362 Pearl St., Buffalo, N. Y.

Dorr, L. BrapDiey, A. B., M. D., ‘96, . . . - 300 Jefferson St., Buffalo, N. Y.

DORR VSS HOBART, “Phe, GiO55) scene omens 789 Prospect Ave., Buffalo, N. Y.

Dort, Miss ExizaBETH, '96, ... . . . . 608 Fillmore Ave., Buffalo, N. Y.

DousLepay, Henry H., Esg.,’90, . . . 715 H St., N. W., Washington, D.C.

DreEscHEr, W.E., ’87, . ; Hide . Box 1033, Rochester, N. Y.

DunuaM, E. K., M.D, ’92, . Bellevue Hospital Med. College, New York City.

EasTMAN, Lewis M., M.D., F.R.M.S., '82, 772 W.Lexington St., Baltimore, Md.

EIGENMANN, Prof. C. H.,’95,. . . . University of Indiana, Bloomington, Ind.

E.uiottT, Prof. ARTHUR H.,'9I, . . . 2Ist St. and Avenue A, New York City.

EUsWer;, JOHN <M; D:, 183,42) elie Ae Gee eee eer P. O. Box 454, Denver, Col.

ELWELL, A. T , ‘89, Se EL at esas he ee 16 Pearl St., Council Bluffs, Iowa.

Evans, Cuas. H., M.D, ‘96, Pe at BRO rater ae sd) shee noe Cantonsi@Ohios

Ewe Lt, MarsuHatt D., LL. D., M. D., F. R. M. S., 8s,

613 and 614 Ashland Block, Chicago, Ill.

PETE, ;ADOEPHS MDs, COIs). ceuien weenie ce 520 E. Main St , Columbus, Ohio.

FELL, Geo. E., M.D,

B.R. M.S; 178... ..:. 72 Niagara St. Buflaloj Nowe

FELLows, Cuas. S., F. R. M.S, '83, 28 Chamber Commerce, Milwaukee, Wis.

ERRIS SE ror vELARRY» be OOsme eens ia years Yale University, New Haven, Conn.

Fietp, A.G.,M.D,’82,..... . . .. -Summit Place, Des Moines, Iowa.

IPISHERS MAK = (9950.2) cues . . . . «Zeiss Optical Works, Jena, Germany.

FLEMING, Miss Mary A., ‘96, Beer ee ote 13 W. Chippewa St., Buffalo, N. Y.

FuinT, JAMES M., M.D.,’91,... .. . ‘‘The Portland,’’ Washington, D. C.

FH Ox;,OSCARNG5/-025u nt Ry FROG Sota ticea t= Orton sou ep. Washington, D. C.

Forp; Prot, D,k.,)Ds D.,; ‘Sr, Spee Metter one ae Female College, Elmira, N. Y.

FOSTER; AGNES WINSLOW;,.93)) sco cine cae oe ates Cate ege oes Brewster, Mass.

IPRENCH,, GALE}, MiiD 6986) on oe eae datas 5219 Center Ave., Pittsburg, Pa.

Futter, Cuas. G., M.D, F.R.M.S, '81, . 38 Central Music Hall, Chicago, IIl.

GAERTNER; (ERED, *MiID 1875s) et eee 3519 Penn Ave., Pittsburg, Pa.

Gace, Prof. Simon H., B.S.,'82,. . . . . . Cornell University, Ithaca, N. Y.

GAGE; Mrs; SUSANNA) PHELPS,875 (oa )s oan ene on ene «+ Je Selthalcary Neg

GaTEs, ELMER, '96, SHS eS saree hea Soke coe ee Chevy Chase, Md.

GieEason, S.O., M D, '80, . wlipen, trans eee ah Cone eames «. « Elmira; Nieye

GREEN, Miss IsaBELLa M., ere S., Ge “ St. Mary’s School, Raleigh, N. C.

GREGORY, JAMES C., M. D.,' Oe HES Sry iain up AY Oe Nyack-on-Hudson, N. Y.

GRIFFITH, BEN. Wi, 92,0. 350 2 24) We State St..eos Angeles, Cal.

GriFFITH, J. D., M. D., 87,

Rialto Building, cor. Ninth and Grand, Kansas City, Mo.

THE AMERICAN MICROSCOPICAL SOCIETY. 203

Haac, D.E,M.D., F.R. M. S., '86, . . 1121 Washington St., Toledo, Ohio.

Hanks, Henry G.,’86. .. . . . . 718 Montgomery, St., San Francisco, Cal.

Harpinc, Lawrence A., B. Sc., Ph. D.,’90, . 16 Seventh St., St. Paul, Minn.

HasENCAmpP, Oscar, M. D.,’97,. . . Cor. Cherry and Ontario Sts., Toledo, O

HATFIELD, JOHN J. B.,’82, . . . . . . . 333 Arsenal Ave , Indianapolis, Ind.

Hays, Jos A., '96, . : ones . . 147 S. Eighteenth St., Pittsburg, Pa.

HEALD, GEORGE HENRY, M. D., 2LOOS Vasarremoes . . . Battle Creek, Mich.

HEINEMAN, H. Newron, M. D.,’g!1, . . . . 60 w. Fifty-sixth St., New York.

RIDRTZOER, ARTHUR, At. MicDs "O05 (sme ehscd. 6 6 hE. . . - Halstead, Kan.

Eun RRBERT MPH )7875.1 +. =... . . 24 High St. Buffalo, Nay.

HGKEMAN, JOS, E1-,) MD, “O0,-f 5 2 sk III Steuben St., Pittsburg, Pa.

IOP BROOKS Mic esol. Dn S250e a. len hs eed 46 E. Twenty-first St., New York.

ELOEMES PEAS 50D) DiS 5 PO4g a alto soy a banks ‘ . . . Grand Rapids, Mich.

FIOSKING WM. 795. S022" os Ye : ee Bi S. Clark St., Chicago, Ill.

Howarp, Curtis C., M.D, 83, ae “Starling Medical College, Columbus, O.

Howe, Lucien, M. D., F. R. M.S.,’78, . . . 87 W. Huron St., Buffalo, N. Y.

Huser, G. Cari, M. D., F. R. M.S.,’90,. . 24 E. Ann St., Ann Arbor, Mich.

FLU MPHRE GIO). eon D1 OSs 0, Gin., s-cs, liens." sia"e . Jamaica, N. Y.

1S SS oe) (ol DY fee ae oe a) 09) Burling Te Nee Rochelle, N. Y.

JAMEs, BusHrop W., M.D, ’94,

N. E. cor. Green and Eighteenth Sts , Philadelphia, Pa.

JAMES; PRANK Ls Ph. D:, M.D: '82;. <5. 3... 615 Locust St., St. Louis, Mo.

JamEs, Geo. W,'92, . . kre ate . . 108 Lake St., Chicago, Ill.

Jounson, Frank S., M. D., 83, Saher cir: . 2521 Prairie Ave., Chicago, Ill.

JOHNSTON wee yIe DY eM D060)... as sas oedies shes Sepsis Whittier Gale

Ke tticort, D. S., Ph. D., F.R.M.S.,’79, . State University, Columbus, Ohio.

PERIEOG Gre oeede Meno 7 O.ye) vel hey) cuca . . . . Battle Creek, Mich.

KELLOGG, CLiIFFoRD WatcotTT, M. D., '96, . 144 CDwight St., New Haven, Conn.

AGHNNED Ya HOMAS SOO) aie ib ih sin Te ek be hee So eo erMe te New Brighton, Pa.

KERR, ABRAM TUCKER, JR,’95, ....°*. . » . 1368 Main St., Buffalo, N. Y.

Kinespury, BENJAMINF ,A.B,M.S.,‘94, ...... ier aeelthaGass Nea ve

RE RGPATRG Kv lease O58 cn sai oa (aout (oil is ap sy adele. . . . « . Springfield, Ohio.

RSTO A ML ate OFT Ne See e eae Cita (58h) te, Ga pe weet a 335 Superior St., Toledo, O

ISNA OV VI Mca EA any NEonD)s iOS) oto 3808 hs east rey) obs 1486 69th St., Chicago, Ill.

LEC ewa\e 1 Bee fo Dee) (us as ee ee eS Ogee 53 S. Fourth St., Easton, Pa.

ESRART VWI TE DAM 9105 sc csr Shiela tic evict ees = . 411 W. 5oth St., New York.

Krauss, Wo. C., B.S., M. D., F. R M.S., ’90, 371 Delaware Ave., Buffalo, N. Y.

RGUINE A Een Vis 17. Oarcicteuewieec: seein! vs: ltr eee 79 Court St., Fort Wayne, Ind.

Lamp, J. Mervin, M.D.,’oI,. . . . . . 906 G St. N. W., Washington, D. C.

WANDSBERG, 7A) 70, <1 & etele. . - . . 145 Woodward Ages Detroit, Mich.

Latuam, Miss V. A., M. D., DD. Si PaRoM eS: oS:

808 Morse Ave , Chicago, Ill.

204 THE AMERICAN MICROSCOPICAL SOCIETY..

Lawton, Epwarp P.,'88,........ +». « +3 Linden’Ave, TroyyNuw:

TERIEPE, [es LARRY; (O03 oF 6 2 woe Soe ve nulls 2d and Franklin Sts., Reading, Pa.

Lewis, Mrs. KATHARINE B., ’89, . “ Elmstone,” 656 Seventh St., Buffalo, N. Y.

TIE WIS; PRAY V5 (OT Sol Sa) aha" ley we io nee eae ee . Dixon, Il.

Ligsey, Prof. Wm., D Sc.,’88, . x hg IRs, . Brine Neale

Line, J Epwarp, D. D.S., F. R. M. S., Ooi 246 y State St., Rochester, N. Y.

LGCKE, | JOHN) D:,\'93,° 2-0 eh a Lafayette Sq., Washington, D. C,

Loms, ADouPH, ’92,:.. - . . «+ + +: «+. 48 Clinton Place, Roehester iia

Loms, Henry, ‘84, aye eras . . . . .48 Clinton Place, Rochester, N. Y.

Loomis, CHANDLER H., 97, anion Dredging Co., 31 Pine St., New York City.

Loturop, Ear, P., M.D,’96, ... .. - 153 Delaware Ave., Buffalo, N. ¥.

LoOvEwerotsk: (Gio oeks re .... . 80 E. 55th St., New York City.

LOVERAND CACGE (MLS sity ari soe ome ones .-. . New Haven, Conn.

Lyon, Howarp N., M.D.,’84,. ..... . 39 9 Belleview Place, Chicago, Ill.

Manton, W.P,M D., F.R.M.S., 85, . 32 West Adams Ave, Detroit, Mich.

MarsHALL, Cotuins, M.D., ’96,. . . . . 2507 Penn Ave., Washington, D C.

MARSHALD, WM, R-5 (O2 nhs. Aer ae) iw Pounetne. <meta . Coudersport, Pa.

MASTERMAN :DEMER) EF), 707s sen oo eae is : . . - New London, Ohio.

MATSON; EUGENE G:, M-)Di, ’96,-.>. = ..- eee of Health, Pittsburg, Pa.

McCatta, ALBERT, Ph. D., ’80

414 Monadnock, Dearborn and Jackson Sts., Chicago, Ill.

IMGICAY;, JOSEPH,, 945.4%.) ger aerate 1... 245 Bighth St) roy, Nee

McKim, Rev. HastetT, ’85,. . . . - 33 West Twentieth St., New York City.

MeEapv_er, Lee Doucras, M.D,'96, . . vee W. Seventh St., Cincinnati, Ohio.

Mrrrcors GHAsS. Ges (OG, cc) noe Lo. 5%. 77 Pitth- Ave. Bittsburgeecas

MERCIERS Aj, IM. D795, 5. % . . . . . Zurich, Switzerland.

Mercer, A. CLIFFORD, M. D., F. R. M. ms ‘So,

324 Montgomery St., Syracuse, N. Y.

MERcER, FREDERICK W., M. D., F. R. M. S., ’83,

2540 Prairie Ave., Chicago, Ill.

Miter, Joun A., Ph.D, F. R. M. S., '89, . Niagara University, Buffalo, N. Y.

Mitnor, Cuas. G.,'86,. . . .... ... » 318 Highland Ave:, Pittsburg yvear

MitTIiNG, E. KENNARD, ‘92, Bement his . 326 N. Water St., Chicago, II.

Moopy, Mrs. Mary B., M. D., ’83, . P: O. Box 206, Annex, New Haven, Conn.

Moopy, Rosert O., M.D.. ’9!1,... . . - 1204 Chapel St., New Haven, Conn.

Morck, AucusT,'96,. . . . . . . . National Bank Building, Oil City, Pa.

Moors, Prof. V. A., M.D., ‘87, . « « » « . . Cornell University, Ithaca, Nowe:

Mygrs, Burton D.}’97, 2 .°. . 2. 0 + - » « 89 N. Tioga Sti; ithaca) ime

NUNN, RICHARD? J.5 00) D.,'S3;¢ccaeriete lana 119% York St., Savannah, Ga.

OrERTEL, T. E., M. D.;’92,. . . . . State Lunatic Asylum, Milledgeville, Ga.

OnterR, W. Hi; '91j) 8 2a i eo es). 18 Locust St, Pontlanuneen

OLIN, 216s Mie De 00) aa ; . . +. . 110 Henry St:, Detroit; Mich.

OLSEN; ALFRED BERTHIER, M. D, nen . 61 Howland St , Battle Creek, Mich.

THE AMERICAN MICROSCOPICAL SOCIETY. 205

Paguin,. Paut, M. D,, ’g1, : eee e + 3536 Olive St.,.St- Louis; Mo.

Park, Rosweci, A. M., M.D, 84, . . . . 510 Delaware Ave., Buffalo, N. Y.

RAPTRICK;“E RANK, Ph. D:; oF; =< . . . . 601 Kansas Ave., Topeka, Kansas.

BRASE-OHRED NG! (O7)) 1 eens ene scua : . . - Box 210, Altoona, Pa.

eNNOGKA TED: 79s ais Saas see ot. Wa Woodland Ave., Philadelphia, Pa.

Perry, StTuarT H., Esgq., ‘90,

Cor..Saginaw and Lawrence Sts., Pontiac, Mich.

Prratae MAGNUS. Eso. Ol, «0: -. --- >» - 445 Grant St:, Pittsburg, Pa:

EMwWONKA, B., Hsq.,'97, .- - = >-- . - - 243 Superior St., Cleveland, Ohio.

Beach, Oro... M.D, “of.

N. W. cor. Eighth and State Ave., Cincinnati, Ohio.

ER MPECH MBE. [eg O75! . 2) iar a, 1009 Liberty Ave., Pittsburg, Pa.

Pyspurn, GEorGE, M. D.,’86, . ...... . . 1011 H St, Sacramento, Cal.

PAUP RESU GENE ACY S0.05) Ga) al's\l eat ok S! as ~ = = = 2 Bethlehem? Pa;

REGO @RAVMONDIG.5°97. .2'. cs). Ske 108 Univ ersity Ave , Ithaca, N. Y.

REMINGTON, Neste VD SOL, oo) <p ESg2 Pine Sf, Philadelphia, eae

ReYBURN, Ropert, M.D,’90,.... 2129 F St., N. W., Washington, D. C.

REYNOLDS, WILLIAM GEORGE, M.D.,’97,-.... .. - . Woodbury, Conn.

IGE MRRANGISZOGOLT GOs. ath. okies ten Savas ou cata OLeeltons bar

Rossins, Henry A., M. D.,'9!1, . - .1750M St. N. W., Washington, D. C.

Rocers, Prof. Wo. A., A. M., Hon, F.R.M.S., '82, . . . . Waterville, Me.

Sampson, ALLEN W.,M.D.,’96, .. . a Penn Yan, N. Y.

SCHAUFELBERGER, F. J., M. D.,’90, .. . . 713 Second St., Hastings, Neb.

SCHRENK, HERMANN VON, 93, . . . - Shaw School of Botany, St. Louis, Mo.

ScHMITz, HENRY, ’96, . . Of: . . . . 518 W. Chicago Ave , Chicago, Ill.

SCHWERDTFEGER, Louis CHARLES, Esg,’96, .. . . Lincoln, Logan Co, Ill.

Seaman, Wo. H., M. D., 86, . . 1424 Eleventh St., N. W, Washington, D. C.

SEcoR, JABIN A., '95, - bee Eh Saat e sere isy cae eo hae ah, ote MILA NEON

SSMU LOE Viet wrOb i, s/s 1s) etaebyetls iste. cheatin oe patie Chico Gale

EAR ERM ers GeO yn 1 t-1Ke unis) 2, @) 2. 800 Adams: St-,, bay Gity, Mach.

Saenz, (CHAS 9:5 9256.2.) a CP eR By. poe oe Hoboken, N. J.

SIEMON, RUDOLPH, ’QOI, . . . . . .22E. Jefferson St., Fort Wayne, Ind.

SmitTH, CHAUNCEY P., M. D., ’96,. . 489 iy tasvene Ave., Buffalo, N. Y.

erat |. (3 190, 6 Ss - s,s. ve, 23Y Carondelet St., New Orleans, La:

SDI | OAS ASR okey Saco US Noe, ee thee oe Sep ete ener om Sam ge lO) shor

STEDMAN, J M., ’87, . . EO ee ee aE ae OLN pias eo:

SrewartT, ALonzo, M. D.,’96, . . . . . 217 N. Twelfth St., Philadelphia, Pa.

StiLtson, J.O,A.M,M.D,’80, . . . . 245 N. Penn St., Indianapolis, Ind.

STOCKWELL, Ropney R.,’96,...... . . 553 Broadway, Alliance, Ohio.

STOWELL, THomas B., A.M, Ph. D., ’82,. . Potsdam, St. Lawrence Co.,N Y.

Summe_rs, Prof. H. E.,’86, . . . . . . University of Illinois, Champaign, Ill.

206 THE AMERICAN MICROSCOPICAL SOCIETY.

TERNAN, JAMES C., '93, .

Tuoma, Fripouin, M. D.,'96,. .

Tuomas, Miss Mary E., Ph. B., ’96, .

Tuomas, Prof. Mason B, ’90, -

THORNBURY, FRANK J., M. D., ’96,. .. .

Timmins, GEORGE '96,

Tivy, W. H., ’81,

TWINING, FREDERICK E, ‘a6,

TWITCHELL, GEo. B., '86,

VANDERPOEL, FRANK, M.E., '87, .

VEEDER, ANDREW T., M. D., ’83,

VeEDER, M.A.,M.D,’85, . :

Vorce, C. M., Esg., F.R. M.S, 78,

VREDENBURGH, E. H., ’84, .

WAGENHALS, Rev. SAMUEL, ’82,

Watmscey, W. H., F. R. M.S, ’78,

Ward, Prof. Henry B., A M, Ph. D.,

Weber, Prof. Henry A., Ph. D , '86,

WEIGHTMAN, CuHas H.,’86,.

WeEtcu, Geo.O, M.D, ’oI,

WENDE, Ernest, M.D,’91,

e ERUM, J. H., 93,

NESt. GHAS ch. leleD), FRM S. "70;

. 7th and Edmond Sts, St. Joseph, Mo.

alll ER, H. W., Mie 8G; ties

. Bausch & Lomb Optical Co., Rochester, N. Y

1072 Lovejoy St., Buffalo, N. Y.

. Meyersdale, Pa.

: Wabash Gollese Crawfordsville, Ind.

. 401 Delaware Ave, Buffalo, N. Y.

. Syracuse, N. Y.

rage N. Second St., St. Louis, Mo.

. P. O. Box 990, Newark, Ohio.

. 556 Freeman Ave., Cincinnati, Ohio.

191 Roseville Ave., Newark, N. J.

. McClintock Building, Pittsburg, Pa.

. - Lock Box 1108, Lyons, N. Y.

- 5 Rouse Block, Cleveland, Ohio.

. 122 S. Fitzhugh St., Rochester, N. Y.

- Box 382, Fort Wayne, Ind.

. 134 Wabash Ave., Chicago, Ill.

87,

University of Nebraska, Lincoln, Neb.

1342 Forsyth Ave., Columbus, Ohio.

. 5859 Michigan Ave , Chicago, III.

. Box 416, Fergus Falls, Minn.

- 471 Delaware Ave., Buffalo, N. Y.

508 Adams St., Toledo, Ohio.

. 76 Pierrepont St., Brooklyn, N. Y.

WHE vcp.Ley, H.M,M.D, Ph.G,F.R.M. S., ’90,

WHITE, JONATHAN, EsgQ., ’gI,

Waite, Mosss C., M. D., ’85, .

Wait ey, JAmEs D., M.D,’85, .

Wriarp, Martin S., '86,

WIEGAND, Kart McKay, B.S,’94,. .

WILLIcH, CHAS., JR., 90, .

WILison, LeEonipas A., Eso , ’85, .

Witson, Mrs. Mary R., M. D., 95,

Woopwarp, ANTHONY, ’85,

Woopwarp, A. L., ’97,

Woo.toMaN, GEo. S., 79, -

Younc, Aucustus A., M. D., ’92,

YzNAGA, JOSE M., Esq., '90, .

ZENTMAYER, FRANK, ’QI,

2342 Albion Place, St. Louis, Mo.

. . 14 Maple Ave, Brockton, Mass.

. Box 1674, New Haven, Conn.

. Petersburg, Ill.

. . 21 Walnut St., New Britain, Conn.

; ae . Ithaca; Wns

. 696 President St., New York City.

. 112 Public Square, Cleveland, Ohio.

3 - Ithaca,eNeue.

fees Ww. 128th St., New York City.

. 93 Park Ave, Utica, N. Y.

. 116 Fulton St., New York City.

ee . Newark, Wayne Co., N. Y.

. 612 F St., N. W., Washington, D. C.

. 209 S. Eleventh St., Philadelphia, Pa.

THE AMERICAN MICROSCOPICAL SOCIETY. 207

HONORARY MEMBERS.

amepmorr iy, 10D Boks Ma Si 2 haces a Ue ce) eee we ODeRUIN, Ohio!

Crisp, FRANK, LL. B., B. A., F. R. M.S.,

5 Landsdowne Road, Nottingham Hill, London, England.

DALLINGER, Rev. W. H., F.R.S., F. R. M. S.,

Ingleside, Lee, S. E., London, England.

FaDSON, IKev:G. 1, A. M., EG. .D:, PoR..M.S:,

6 Royal York Crescent, Clifton, Bristol, England.

Maovpox, R. L., Greenbank, 45 Park Road, Portswood, Southampton, England.

SMa wi AMIE TON s., ols: Lharkcpkts Wi oen .. 5a. canes: . . . Geneva, N. Y.

AiG a Bie] Sea & Desay Led Jat) evel SCO" betes ei rere Some eae 5 153 Fourth St., Troy, N. Y.

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