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Journal of Parasitology 


A QUARTERLY DEVOTED TO MEDICAL ZOOLOGY 


EDITORIAL BOARD 


FRANKLIN D. BARKER ALLEN J. SMITH 

The University of Nebraska The University of Pennsylvania 
CHARLES F. CRAIG JOHN W. SCOTT 

Medical Corps, U. S. Army The University of Wyoming 
WILLIAM B. HERMS CHARLES W. STILES 

The University of California U. S. Public Health Service 
BRAYTON H. RANSOM RICHARD P. STRONG 

U. S. Bureau of Animal Industry Harvard University 
WILLIAM A. RILEY JOHN L. TODD 

Cornell University McGill University 


ROBERT T. YOUNG 
The University of North Dakota 


VOLUME. 1 
1915 oe 
-%m 2 
» S240 
LO: 


Managing Editor 
HENRY B. WARD 


The University of Illinois 
URBANA 


CONTENTS OF VOLUME I 


SEPTEMBER, 1914. NUMBER 1 


PAGE 

PNG O UMN CEMMUISINGIO DIN Se creceiehcicis c/aic cre syetetel sVene sande PERN era ca ere tio a wsate Navaho eiees 3 
Tue DESTRUCTION OF THE VITALITY OF CySTICERCUS Bovis BY FREEZING. 

Ms PMBISUAUNTS OMI ney hae, Lai ice cvatstasaytterey ie revche al oiatece Biase) ora. sietaceveie ae te.d aiele bie ole 5 


SUMMARY OF Two YEARS’ Stupy OF INSECTS IN RFLATION TO PELLAGRA. 
PNTSTENN Guillet UINONITENGS ete syae) clevs «aie / svais eye era ei siie esx SEG Miter he ceca ones beget, elle, 


VARIATION IN OxyurIAsS: Its BEARING ON THE VALUE OF A NEMATODE 
MORMUIGAG ES DANDEEY 0. UHRAGKER:. cts srjeretersiniy 6 ec BES ters. Vo ee on Le 


OBSERVATIONS ON THE Eccs oF ASCARIS LUMBRICOIDES. WINTHROP D. Foster 31 
Dr. Notr’s THEORY oF INSECT CAUSATION OF DISEASE. WILLIAM A. RitEy 37 
RHABDITIN: CONTRIBUTION TO A SCIENCE OF NEMATOLOGY. N. A. Coss.... 40 


EXPERIMENTAL INGESTION BY MAN OF CYSTICERCI OF CARNIVORE TAPEWORMS. 
INTAUGRIGID AGE JS UNID peeve Sane’ ale teas Pe os aa ed) Ob i a Te ear ge 75 42 


A Pecurttar MorpHoLtocic DEVELOPMENT OF AN EGG OF THE GENUS TROPI- 
DOCERCA AND ITS PROBABLE SIGNIFICANCE. WINTHROP D. FosTer....... 45 


THE AcTION OF ARSENICAL Dips IN PREVENTING T1IcK INFESTATION. H. W. 
GRAB IDI EGE Phen Sil oy cticeeec in sioiane be By ciate Ree tea arse A eS 


EorHyNcHUS: A ProposeD NEw NAME For NEoRHYNCHUS HAMANN PRE- 


CE SCTE ees AV PA Nia ODIEVAIVE uevotai ccs told ccs Sey cvaceisia ot ara diate avakermicfondle ee s/ashays 50 
THE HELMINTHOLOGICAL SOCIETY OF WASHINGTON, PROCEEDINGS............ 52 
INIOTIOOS ead do ake OG Rae aS or AC ee aes Soe tt Sore OA SiG t 54 

DECEMBER, 1914. NUMBER 2 
Mick PARALYSIS: JOHN Ie: LODDsa. .5-4- eae rete ears atone aia oslo one Pe rer gaan 
LarRVAL TREMATODES FROM NortTH AMERICAN FRESH-WATER SNAILS. WIL- 

TEAMS VVPATDERY, GORA earner anclarae sacsceietararate miter eat Deas ctor MeKc tas Gace 65 
NEW VARIETIES AND SPECIES OF MALARIA PLASMODIA. CHARLES F. Craic... 85 
Tuer Porson GLANDS OF THE LARVA OF THE Brown-Tart MotH (Evuproctis 

GHRYSORRHOPA® JGININ)): CORNELIA Es IGEPEIART: coc chase snc ewe ies cn cess 95 
An APPEAL TO AMERICAN HELMINTHOLOGISTS. AL. MRAZEK............... 104 
KILLING SMALL ARTHROPODS WITH THE LEGS EXTENDED. R. A. CooLey..... 105 
THE HELMINTHOLOGICAL SOCIETY OF WASHINGTON, PROCEEDINGS...........-. 106 
INIGHISS) GS Senate Bien 6 Ben Ban Ge hoe Oe o OLN KRG SRS eae eee 106 

MARCH, 1915. NUMBER 3 
PuIDERIE OLSON em VERNON sea ICRTBOGG a seeps aise eee ce s'< «cian se le evaate are 107 
SARCOSPORIDIA ENCOUNTERED IN PANAMA. S. T. DARLING.............-005 mllalis: 
OTACARIASIS IN THE BIGHORN. HENRY B. WARD..............-eeceecceeee Onis! 


CiOcGtREAEA. LINGUA (CREPLIN). EDWIN LINTON... .....0i0600sc000eceadne a WAS 


iv CONTENTS OF VOLUME I 


THe Hasirs, Lire History AND STRUCTURE OF A BLoop-SUCKLING Museau ae 
Larva (Protocalliphora azurea). ALBERT F. COUTANT..........0.0000 135 
EXPERIMENTS ON CysSTICERCI OF Taenia pisiformis AND OF Taenia serialis 
GERVAIS UP AMES oH 7 INCIER Do a5, cimsied «o-cicis bree eo biscle ental op onep eee ws dal 
HELMINTHOLOGICAL SOCIETY OF WASHINGTON, PROCEEDINGS..............--- 154 
REVIEWS i PAINID aIN(OMES 33 oie crete ais cisic ereisuets. Sain Grate die eretb hice ate o «Sem eI Cee 156 


JUNE, 1915. NUMBER 4 
THE PARASITE OF ORAL ENpAMEBIASIS, Endameba gingivalis (Gros). 
ALLEN J: SMITE AND UM. I, BARRETT <. o's: sjcutee en ee @ ote he 159 
ACANTHOCEPHALA IN NortH AMERICAN AMPHIBIA. H. J. VAN CLEAVE..... 175 


THe PROTECTION OF PARASITES IN THE DiGESTIVE Tract AGAINST THE 
ACTION OF THE DIGESTIVE ENzyMES. W. E. Burce AND FE. L. Burce... 179 


PARASITES OF THE AMERICAN Muskrat (Fiber zibethicus). FRANKLIN D. 


IBINRKIER Dod rae pistes totes ee orcete ot one aicnaie (iar shen ebekett eae YR eee eee Bea inst 184 
Gorpius LARVAE PARASITIC IN A TREMATODE. WILLIAM WALTER CorT...... 198 
THe HELMINTHOLOGICAL SOCIETY OF WASHINGTON, PROCEEDINGS.........-- 200 
ROOKIE VIEWS) Geyeees sco cioteintsre-teoy cle evans Sutin le ape ors auaagda Sn Rat Dee Ree OEE eae 204 
INOTES Se ets eee ofa ccs et ici tpi e otras sce tebe ee ae PER ec ge en yi nas 206 


LLLP Le FNC LS 


The 
Journal of Parasitology 


A Quarterly Devoted to Medical Zoology 


Volume | 


EDITORIAL BOARD 


FRANKLIN D. BARKER ALLEN J. SMITH 

The University of Nebraska The University of Pennsylvania 
CHARLES F. CRAIG JOHN W. SCOTT 

Medical Corps, U. S. Army The University of Wyoming 
WILLIAM B. HERMS CHARLES W. STILES 

The University of California U. S. Public Health Service 
BRAYTON H. RANSOM RICHARD P. STRONG 

U. S. Bureau of Animal Industry Harvard University 
WILLIAM A. RILEY JOHN L. TODD 

Cornell University McGill University 


ROBERT T. YOUNG 
The University of North Dakota 


HENRY B. WARD, MANAGING EDITOR 
The University of Illinois 
URBANA 


ANNOUNCEMENT 


The advisability of establishing an American publication in the 
field of parasitology has been under discussion for some time. Such 
a journal is clearly demanded by the increasing amount of work in 
this field, the growing importance of the subject in its broader aspects 
as related to disease in man and other animals and the intense biological 
interest in associated theoretical problems, together with the evident 
advantages of a representative publication and the lack of adequate 
opportunity for printing such papers elsewhere. 

THE JOURNAL OF ParaAsriToLocy will be a medium for the prompt 
publication of briefer papers and research notes on animal parasites. 
Emphasis will be laid on the morphology, life history and biology of 
zooparasites, and the relations of animals to disease. Under present 
conditions it will not be practicable to print monographic articles, and 
ordinarily individual papers will be limited to ten or fifteen text pages. 

THE Journavt will publish the reports of the Helminthological 
Society of Washington and a brief record of personal and institutional 
items in parasitology. Individual papers will not usually be reviewed, 
but books or monographs of noteworthy character and _ technical 
methods of marked value will be given appropriate notice. An effort 
will be made to eliminate the casual notice or abstract; critical sum- 
maries by those who are entitled to pass judgment in the special field 
are welcomed and some such are already pledged. 

The final policy of THE JouRNAL will be developed in the light of 
experience to the end that it may contribute as effectively as possible 
to the dissemination of knowledge and the encouragement of teaching 
and research in parasitology. 

A guarantee fund subscribed by various individuals and institutions 
assures the regular appearance of this periodical quarterly at least 
for a three-year period, so that the Editorial Board will devote its 
attention to determining broadly the needs of the field and the best 
methods of serving them. 

A series of distinguished foreign workers have consented to become 
collaborators in the work of THE JouRNAL, and contributions to its 
pages from some of them have already been received. Owing to 
present confusion in the mail service this list is not perfect and will 
appear later. 


4 THE JOURNAL OF PARASITOLOGY 


The expressions of interest and encouragement that have come 
unsolicited on the appearance of the preliminary announcement indicate 
clearly the favorable reception awaiting the appearance of the new 
publication. It will depend for its success on the continuance of this 
attitude, and to that end welcomes all suggestions as to the methods by 
which it may best serve the field of science to which it is devoted. 
It hopes to deserve the approval and continued support of the pro- 
fessional world. 

THE EpirorrAL BoArp 


whe. Journal of Parasitology 


Volume 1 SEPTEMBER, 1914 Number 1 


THE DESTRUCTION OF THE VITALITY OF CYSTICER- 
CUS: BOVIS? BY EREEZING 


B. H. Ransom 


Bureau of Animal Industry, U. S. Department of Agriculture. 


The question as to the length of time Cysticercus bovis may survive 
after the death of its host has been quite definitely settled by the 
researches of Perroncito, Zschocke, Ostertag and others. Perroncito 
(1877) found that the cysticerci in an artificially infested calf were all 
dead fourteen days after the slaughter of the animal. However, 
Zschocke (1896) succeeded in infesting the human subject with a 
tapeworm by feeding five cysticerci from beef kept from fourteen to 
sixteen days after slaughter. No infestation followed the swallowing 
of five cysticerci from beef kept twenty-one days after slaughter. 
Ostertag (1897) examined in a thermostat a large number of cysticerci 
from beef kept in cold storage at temperatures above freezing for 
various periods of time after slaughter and concluded that the para- 
sites are no longer capable of development on the twentieth day, 
although slight movements were observed in a few cysticerci as late as 
twenty-four days after slaughter. These results were confirmed by 
feeding experiments in which thirty-four persons swallowed cysticerci 
from beef held in cold storage at temperatures above freezing for 
from twenty to twenty-one days after slaughter. No tapeworm infes- 
tation resulted in any case. 

The conclusions from these investigations are that a lapse of 
twenty-one days after slaughter is amply sufficient to insure the death 
of the beef cysticercus, and on the other hand that fourteen days is not 
sufficient, although in some cases, as determined by Perroncito in one 
instance, the parasites may have lost their vitality within this shorter 
period of time. Cognizance has been taken of these results in the 
meat-inspection regulations of Germany, United States and other 
countries, which provide that beef carcasses showing infestation with 
cysticerci in a certain slight degree may be passed for food after 
retention in cold storage for twenty-one days. 


6 THE JOURNAL OF PARASITOLOGY 


The question of the period of time Cysticercus bovis may survive 
after the death of its host having been settled, the next question which 
arises is whether this period may be shortened by artificial means. 
The means which naturally suggests itself as the least objectionable in 
its effects on meat and the most practicable of application is exposure 
to low temperatures. Reissmann (1897) has reported that beef cysti- 
cerci inserted into the depths of large pieces of meat which were then 
kept at temperatures of from — 8 to — 10C. (17.6 to 14 F.) do not sur- 
vive when thus exposed for three days. Cysticercus cellulosae appeared 
to be somewhat more resistant and required four days exposure before 
its vitality was destroyed. Prior to Reissmann, Glage (1896) noted 
that in the case of a measly pork ham (11 kg. in weight) which was 
exposed to a low temperature and solidly frozen, most of the cysticerci 
were still alive after two days of such exposure. Asa result of several 
experiments Boccalari (1903) concluded that Cysticercus bovis and 
C. cellulosae die in four days at a temperature of from — 4 to —6 C. 
(24.8 to 21.2 F.) and in six days at a temperature of from 0 to —2 C. 
(32 to 284 F.). 

Recent experiments by the writer on Cysticercus bovis have led to 
somewhat different results than those obtained by Reissmann and 
Boccalari, and in fact have shown that the exposure of measly beef to 
temperatures as low as 15 F. for four days is not sufficient to insure a 
complete destruction of the vitality of the cysticerci. In these experi- 
ments two beef carcasses, heavily infested with live cysticerci, were 
used. The carcasses were allowed to hang for about twenty-four hours 
after slaughter in a chill-room, the temperature of which was somewhat 
higher than the freezing-point. They were then quartered and placed 
in a cold-storage compartment (freezer), in which the temperature 
varied during the experiments between 11 and 15 F.; most of the time 
between 14 and 15. The temperature of the freezer was taken at 
four-hour intervals. The thermometer used was checked with a 
thermometer recently standardized by the Bureau of Standards. In 
the case of one of the carcasses, a quarter was retained in the chill- 
room, in order that check observations might be made on unfrozen 
cysticerci. Examination of one of the quarters of beef was made two 
days after it had been placed in the freezer, at which time it was found 
that the deeper portions of the meat had not yet become solidly frozen. 
_ All of the beef kept in the freezer longer than two days was found to 
be solidly frozen throughout. 

Portions of one of the carcasses were removed from the freezer 
after a lapse of two, three and six days, respectively, allowed to thaw, 
and eighteen to twenty-four hours after removal dissected. The 
cysticerci were isolated, removed from their cysts and examined on a 


RANSOM—DESTRUCTION OF CYSTICERCUS BOVIS 7 


warm stage kept at a temperature of 40 to 45 C. Careful observations 
were made to detect signs of life. If the parasite did not move and 
showed no response to stimulation with a needle-point it was con- 
sidered dead. The heads of those cysticerci which showed no move- 
ment in the retracted condition were evaginated by pressure and care- 
fully observed, as it was found that in such cases the head and neck 
sometimes still showed feeble movements, not perceptible in the 
retracted cysticercus. 

Lack of opportunity prevented a prompt and careful examination 
of thirty-six cysticerci removed from the beef kept two days in the 
freezer, but it was observed that one of them showed definite signs of 
life. These cysticerci were taken from the superficial frozen portions 
of the meat. 

Sixteen cysticerci from the beef kept three days in the freezer were 
examined and seven, or 44 per cent., were found to be alive. 

Sixty-three cysticerci from the beef kept six days in the freezer 
were examined and none was found alive. Six others were removed 
from the same meat with special precautions to prevent possible injury. 
The cysts were left intact, together with a small amount of surround- 
ing muscular tissue. These six cysticerci were swallowed by a human 
subject (the writer). Eighteen weeks (Sept. 23, 1913, to Jan. 29, 
1914) have elapsed and no signs of tapeworm infestation have yet 
appeared. 

Meat from the other carcass was removed from the freezer after a 
lapse of four, five and six days, respectively, and allowed to thaw, 
after which the cysticerci were isolated and examined as in the case 
of the first carcass. 

Forty per cent. of the cysticerci from the beef kept four days in 
the freezer proved to be alive; that is, ten out of twenty-five examined. 

Only one out of twenty-one cysticerci, or 5 per cent., was still 
alive in the beef kept in the freezer for five days, and this one showed 
such faint signs of life that it probably would have been incapable of 
development in the human host. 

Thirty cysticerci were examined from the beef kept six days in the 
freezer and none showed any evidence of being alive. Five others, 
intact in their cysts and surrounded by small portions of muscular 
tissue, were swallowed by a human subject (the writer). An examina- 
tion was made of twelve cysticerci from the portion of the same car- 
cass, which had been kept since slaughter, eight days in all in an 
unfrozen condition, and all were found to be alive and active. Fifteen 
weeks (Oct. 16, 1913, to Jan. 29, 1914) have elapsed since the five 
cysticerci above referred to were swallowed and no evidence of tape- 
worm infestation has yet appeared. 


8 THE JOURNAL OF PARASITOLOGY 


From these experiments it may be concluded that if measly beef 
carcasses are exposed for six days to a temperature not exceeding 
15 F. (—9.44 C.) the vitality of the cysticerci will be destroyed, that 
some may survive in carcasses exposed for five days to this tempera- 
ture, though it is doubtful whether they will retain sufficient vitality to 
develop in the human host, and finally that a considerable proportion 
may survive in carcasses exposed to a temperature of 15 F. for four 
days or less. Though it is possible that the vitality of the cysticerci, 
which were observed to be alive after exposure of the infested beef to 
a temperature of 15 F. for four days, had been so seriously affected 
that they would have been incapable of producing tapeworm infesta- 
tion, the fact that they were alive and active justifies the adoption of a 
longer period of retention when refrigeration is employed as a sanitary 
measure. Likewise it would seem, notwithstanding the evidently weak- 
ened condition of the only cysticercus which survived in beef exposed 
five days to a temperature of 15 F., that it is not justifiable to accept 
five days as a safe period for refrigeration, and that six days should 
be required until it shall be shown that a shorter period of refrigeration 
is fully sufficient to prevent the possibility that cysticerci present in the 
refrigerated meat may retain enough vitality to continue their develop- 
ment in the human host. On the basis of the results which have been 
herein recorded, an amendment to the federal meat inspection regula- 
ticns has been issued providing that beef carcasses showing a certain 
slight degree of infestation may be passed for food if held for six 
days at a temperature not exceeding 15 F., as an alternative to the 
requirement of retention for twenty-one days. As over 40,000 beef 
carcasses are annually retained on account of Cysticercus bovis in 
establishments under federal inspection, this modification of the regula- 
tions will result in a considerable saving in the handling of such 
carcasses. Some carcasses, particularly heavy carcasses of the highest 
quality of beef, suffer little or no deterioration when held for twenty- 
one days in coolers at temperatures above freezing, and these are likely 
to be held in coolers as heretofore for the full twenty-one-day period. 
Many of the carcasses, however, which are retained on account of 
Cysticercus bovis, are of such a character that they cannot be kept 
unspoiled for three weeks unless they are frozen. “Under the new 
regulations, instead of being refrigerated for three weeks, these car- 
casses will be held for six days at a temperature not higher than 15 F. 
and then released for food. The refrigeration expense will thus be 
greatly reduced. Only about a third as much cold will have to be 
produced for each carcass, and only about a third as much storage 
space will be required to take care of the carcasses. Heretofore at 
many establishments the freezers have been more or less constantly 


RANSOM—DESTRUCTION OF CYSTICERCUS BOVIS 9 


congested with retained carcasses, and at times more carcasses have 
been retained than there was room for in the available freezer space. 
Such conditions will be greatly relieved by the new regulations. 


REFERENCES 


Boccalari, Abelardo. 1903. La notevole diffusione del Cisticercus bovis nel 
bestiame da macello italiano. Gior. r. Soc. ed Accad. vet. ital., 52: 409-415. 

Glage, Friedrich. 1896. Versuche tiber die Lebenszahigkeit der Finnen. 
Ztschr. f. Fleisch- u. Milchhyg., 6 :231-234. 

Ostertag, Robert. 1897. Untersuchungen tiber das Absterben der Rinderfin- 
nen im ausgeschlachten und in Kthlraumen aufbewahrten Fleische. Ztschr. f. 
Fleisch- u. Milchhyg., 7 :127-132. 

Perroncito, Edoardo. 1877. Esperimenti sulle produzione del Cysticercus 
della Taenia mediocanellata nelle carni dei vitelli; altre prove fatte sulla sua 
tenacita di vita e sul rapido sviluppo della corrispondente Taenia mediocanellata 
nell’uomo. Medico vet., 6:538-553, uls. 1-4. 

Reissmann, 1897. Ein Beitrag zur Frage der Finnenabtotung durch Kalte. 
Ztschr. f. Fleisch- u. Milchhyg., 7 :132-137. 

Zschocke, A. 1896. Zur Frage der Verwerthung finnigen Rindfleisches. 
Deutsche thierarztl. Wcehnschr., 4: 233-236. 


SUMMARY OF TWO YEARS” STUDY’ OF INSEGIS 3 
REEATION £0  PELLAGRA 


ALLAN H. JENNINGS 
Entomological Assistant, Bureau of Entomology 


With the growing interest in pellagra, following the authoritative 
recognition of its presence in the United States in 1907, the study of 
its etiology was taken up by various investigators and the several 
theories of causation were subjected to close scrutiny. 

Prominent among these theories was that of insect transmission, 
first advanced by Sambon, who limited this function to the species of 
blood-sucking gnats comprising the genus Simulium. 

The importance of the disease and the possibility of such a factor 
in its causation, led the Bureau of Entomology, late in 1911, to under- 
take an investigation of the subject in South Carolina, to which locality 
attention had been directed by the state authorities. The writer and 
W. V. King were, early in 1912, assigned by Dr. L. O. Howard, Chief 
of the Bureau of Entomology, United States Department of Agricul- 
ture, under the direction of Mr. W. D. Hunter of the Bureau, to 
investigate the possible relation of insects to pellagra and to gather 
such data as might serve to indicate whether there was ground for the 
assumption that blood-sucking or other arthropods were involved in 
the transmission of the disease in that region. 

In June, 1812, the Thompson-McFadden Pellagra Commission of 
the Department of Tropical Medicine, New York Post-Graduate Med- 
ical School, established its laboratory and began its field work at 
Spartanburg, in Spartanburg County, 5. C. 

Through the courtesy of Capt. J. F. Siler, Medical Corps, United 
States Army, and with the approval of Dr. L. O. Howard, Chief of the 
Bureau of Entomology, the representatives of the Bureau were enabled 
to cooperate with the commission and to study the possible relation of 
insects to the causation of pellagra. 

The work undertaken under these auspices consisted of a general 
study of such insects as appeared after a careful review of the situation 
to present possibilities in this connection. The species which seemed 
worthy of consideration were studied as to biology and habits, with 
special reference to the epidemiology of the disease and to the habits 
of those classes of the population in which appear the great mass of 
the cases of pellagra. 


Paper read before Section K, American Association for the Advancement 
of Science, Atlanta, Ga., Jan. 2, 1914. 


JENNINGS—STUDY OF INSECTS 11 


The homes of pellagrins were studied, together with the sanitary 
condition of their surroundings, and especially careful attention was 
given to the mill villages in which occur many cases of the disease. 

Collections of insects were made and no effort was spared to come 
to an unbiased conclusion in the case of each species studied. Careful 
elimination of such forms as failed to meet our conception of the 
characteristics required was effected on the grounds set forth below. 

Field work was continued until October 15, and the details of the 
work was published as a progress report. In April, 1913, the work 
was again taken up. In June, a hospital for pellagrins- having been 
established in Spartanburg, we were afforded facilities for more 
elaborate laboratory studies, including the attempted transmission of 
pellagra to monkeys by the bites of blood-sucking insects. The details 
of the latter work were carried on by Mr. King and will form the basis 
for a later report. 

As a basis for our work it was necessary to assume that pellagra 
is an infectious disease and that it is capable of transmission by blood- 
sucking insects, but it must be well understood that no positive con- 
victions were entertained and the possibility only of such conditions 
is implied. In weighing the evidence as to the involvement of each 
insect we were impelled to apply Knab’s postulate in this connection, 
and I shall quote its substance: 

In order to be a potential transmitter of human blood-parasites, an insect 
must be closely associated with man and normally have opportunity to suck 
his blood repeatedly. It is not sufficient that occasional specimens bite man 
as, for example, is the case with forest mosquitoes. Although a person may 
be bitten by a large number of such mosquitoes, the chance that any of these 
mosquitoes survive to develop the parasites in question (assuming such 
development to be possible), and then find opportunity to bite and infect another 
person, are altogether too remote. 

The results of the work of 1913 were, in the main, corroborative of 
those of 1912, but further studies by the commission have broadened 
the view and introduced some new elements. 

Two mill villages in counties adjacent to that of Spartanburg are 
equipped with an effective water-carriage system of sewage disposal. 
It was found that in these villages, pellagra has failed to obtain a foot- 
hold, although introduced a number of times. In the town of Spartan- 
burg, also, there appears to be a correlation between the absence of 
sewers and the prevalence of pellagra. 

The studies have also brought out the fact that a close domiciliary 
connection appears to exist between cases originating in 1912 and 1913, 
and older or antecedent cases; that is, the cases developing in these 
years, in the mill villages under consideration, which show a close 
household association with antecedent cases, form a large percentage of 


12 THE JOURNAL OF PARASITOLOGY 


the cases for three years. Cases which have been in less close associa- 
tion with older cases, such as neighbors living next door or across the 
street from them, form a much smaller percentage of the total. Those 
living at greater distances are, in some villages, wanting, the total 
number of such cases being very small. 

That this phenomenon indicates infectiousness is so clear as to 
amount almost to a demonstration. 

The prevalence of Pediculus capitis seems to be somewhat greater 
than we had supposed and we are led to believe that our previous views 
did not reflect the actual condition. This was due largely to the 
improved facilities for observation at our command in 1913 and partly 
also to the overcoming of reticence on the part of pellagra patients and 
their families. 

The evidence gathered does not materially alter our views regarding 
the agency of these insects, but the fact that we had underestimated 
their abundance suggests the desirability of further work along this 
line in 1914. 

The insects on which our studies were especially concentrated were 
the ticks, lice, bedbugs, roaches, horseflies (Tabanidae), fleas, mos- 
quitoes, buffalo gnats (Simulium), houseflies and the stable fly (Stom- 
oxys calcitrans ). 

The ticks (family Ixodidae, the only family of the group repre- 
sented in South Carolina) can be safely excluded by reason of their 
biting habits and life history. The fact that most ticks of this family 
require three hosts during the life cycle, remain attached during each 
stage, drop to the ground at its completion and re-attach to another 
after molting, precludes their incrimination. So rarely could a tick 
remain attached to a human host a time sufficient for its engorgement 
and the completion of the current stage of its development, that its 
chances for becoming infective and living to transmit its infection 
would be practically mil. It must be borne in mind that we are dealing 
with a disease which shows no evidence of the existence of reservoirs 
of its virus among the lower animals. Ticks are not a serious pest in 
Spartanburg County, and those suffering most from pellagra, the home- 
keeping adult females and young children, are those least exposed to 
the bites of ticks. 

The head louse was excluded by us in 1912 because its prevalence 
seemed inadequate to the dissemination of a disease with the epidemi- 
ologic characteristics of pellagra. The occurrence of a considerable 
number of cases among persons whose circumstances and habits should 
safeguard them from attack by Pediculus is opposed to the agency of 
the insects. 


JENNINGS—STUDY OF INSECTS 13 


The relative incidence in males and females is not satisfactorily 
explained by their incrimination and the distribution of cases in the 
individual foci of the disease does not appear, in our opinion, strongly 
to indicate a flightless carrier with a human vehicle. 

Notwithstanding our misconception as to the prevalence of the 
species, additional facts will be necessary to place it among the prob- 
able transmitters of pellagra. 

In large cities, with congested populations, unhygienic surroundings 
and abundance of Pediculus, pellagra does not obtain a foothold in 
spite of the introduction of cases of the disease. 

The bedbug, Cimesx lectularius, although very abundant and uni- 
versally distributed, when considered as a possible carrier of pellagra, 
does not account for certain marked characteristics of the disease. Its 
association with man is of the closest nature and the conditions under 
which a large class of pellagra suffers live, favor in high degree its 
indiscriminate attack on all members of the household generally. But 
the indiscriminate character of its attentions is the strongest argument 
against its incrimination. 

Although the approximate ratio of infection of females to males, 
as a whoie, in the United States is as 3 to 1, we find that among adults, 
nine women are victims of pellagra to every man affected. The ratio 
is much too high to be accounted for by an assumed selectiveness on 
the part of the bug by its opportunity for attack on either sex, which 
must be practically equal, or by a supposititious immunity of the male 
sex to pellagra infection. 

Roaches, though common throughout the region, are negligible in 
connection with our subject unless the disease is found to be trans- 
missible by means of contaminated foodstuffs. Should this be the case 
their role must still be subordinate to that of the housefly. 

The family Tabanidae, which includes the well-known horse flies, 
should be mentioned because of their blood-sucking habits and the 
fact that at certain times and in some localities they attack man with 
a degree of frequency and persistence. These attacks are, however, 
desultory and have no part in the essential economy of the flies. In 
Spartanburg County, flies of this group were found to be far from 
common, and this fact together with their irregular attack on man, and 
an entire lack of association with him, serves to exclude them con- 
clusively from consideration. 

When attention was given to the fleas of the region, a somewhat 
unexpected condition was found to exist. Superficially considered, 
these insects might be thought to present possibilities in connection 
with pellagra transmission, and great care was taken to collect all 
possible information regarding them as well as material for study. So 


14 THE JOURNAL (OF (PARASITOLOGY 


uniform were negative statements as to attacks by them that we were 
forced to believe that as pests of human beings in the locality, fleas 
play but a small part. This is the less remarkable in view of the fact 
that we were unable to collect the human flea, Pulex irritans, at any 
time. The cat and dog fleas as well as a few chicken fleas, Echid- 
nophaga gallinacea, were collected from various hosts and a number 
of rats, captured in the town of Spartanburg, were infested by the 
European rat flea, Ceratophyllus fasciatus, and a considerable number 
of the Indian rat flea, Xenopsylla cheopis. A few specimens of 
Ctenopsvlla musculi were also obtained. 

The sharply defined host habits of most fleas render the species 
which are characteristic parasites of cats, dogs, rats, etc., rarely trouble- 
some to man under normal American conditions. When conditions are 
favorable for the inordinate propagation of the cat or dog fleas or an 
epizootic decimates the host species, as in plague, this may occur, but 
under ordinary circumstances these fleas will remain on human beings 
a comparatively short time and transference from man to man prob- 
ably occurs but seldom. Transmission of human disease by the same 
channel would similarly be unlikely to occur. In addition, the sex inci- 
dence of pellagra cannot be satisfactorily explained by the incrimina- 
tion of these insects. 

The only mosquitoes of the region studied which justify considera- 
tion in connection with possible pellagra transmission are the two house 
species, Aedes calopus and Culex quinquefasciatus (fatigans). The 
latter species is nocturnal in habit, and its incrimination is incompatible 
with the sex incidence of pellagra. 

While the vellow-fever mosquito is emphatically a day mosquito, 
its occurrence in Spartanburg County is by no means constant or 
regular. It should be noted that in spite of its presence in the town of 
Spartanburg, the species was not taken in the country districts or at 
points remote from railroad communication with its more southern 
and regular habitat. In the summer of 1912 no individuals of this 
species were observed, while in 1913, from June 1, the Stegomyia was 
a common and troublesome pest in Spartanburg. At the time of its 
appearance in 1913, the seasonal epidemic of pellagra was well 
advanced and the disease was showing great activity. On no accepted 
theory as to its period of latency, whether of short or long duration, 
can this species be incriminated in view of these phenomena. In spite 
of its day-biting habits, therefore, Aedes calopus must remain excluded 
as a causative agent. 

Our studies in 1912 convinced us that there was little evidence to 
support the incrimination of any species of Simulium in South Carolina 
in the transmission of pellagra. Reviewing the group as a whole, we 


JENNINGS—STUDY OF INSECTS 15 


find that its species are essentially “wild” and lack those habits of 
intimate association with man which would be expected in the vector 
of such a disease as pellagra. Although these flies are excessively 
abundant in some parts of their range and are moderately so in 
Spartanburg County, man is merely an incidental host, and no dis- 
position whatever to seek him out or to invade his domicile seems to be 
manifested. Critically considered, it is nearer the fact that usually 
man is attacked only when he invades their habitat. 

As our knowledge of pellagra accumulates, it is more and more 
evident that its origin is in some way closely associated with the 
domicile. The possibility that an insect whose association with man and 
his immediate environment is, at the best, casual and desultory, can be 
active in the causation of the disease becomes increasingly remote. 

Our knowledge of the biting habits of Simulium is not complete, 
but it is evident, as regards American species at least, that these are 
sometimes not constant for the same species in different localities. Cer- 
tain species will bite man freely when opportunity offers, while others 
have never been known to attack him. To assume that the proximity 
of a Simulium-breeding stream necessarily implies that persons in its 
vicinity must be attacked and bitten is highly fallacious. In Spartan- 
burg County attacks by Simulium seem to be confined to the immediate 
vicinity of the breeding-places. Our records and observations, exceed- 
ingly few in number, refer almost exclusively to such locations. State- 
ments regarding such attacks, secured with much care and discrimina- 
tion from a large number of persons, including many pellagrins, indi- 
cate conclusively that these insects are seldom a pest of man in this 
county. A certain number of the persons questioned were familiar 
with the gnats in other localities, but the majority were seemingly 
ignorant of the existence of such flies with biting habits. This- is 
especially striking, in view of the fact that the average distance of 
streams from the homes of the pellagra cases studied was about 200 
yards, many being at a distance of less than 100 yards, and that 78 per 
cent. of these streams were found to be infested by larval Simulium. 
Such ignorance in a large number of persons cannot be overlooked and 
indicates strongly that our belief in the negligible character of local 
attacks by Simulium is well founded. 

In localities infested by “sand-flies,’ mosquitoes, etc., these pests 
are always well known and the ignorance described above is very 
significant. 

Such positive reports as we received nearly always referred to 
bites received in the open, along streams, etc., and observations made 
of their attack were of those on field laborers in similar situations. 
Males engaged in agricultural pursuits are almost exempt from pellagra 


b 


16 \ THE JOURNAL -OF (PARASITOLOGY 


in Spartanburg County. During the season of 1913, in some two or 
three instances, observations were made of the biting of Simulium and 
some additional and entirely credible reports were received. These 
observations and reports were under conditions identical with those 
referred to in the reports of 1912 and confirm the conclusions based 
on the observations of that year. I would repeat with emphasis that 
it is inconceivable that a fly of the appearance and habits of the preva- 
lent species of Simulium could be present in such a region, especially 
about the haunts of man and attack him with sufficient frequency and 
regularity to satisfactorily account for so active and prevalent a disease 
as pellagra without being a well-known and recognized pest. 

In connection with the conditions in the Piedmont region of South 
Carolina, it may be well to cite the results of a study of those in the 
arid region of western Texas. 

In May, 1913, in company with Capt. J. F. Siler of the Thompson- 
McFadden Pellagra Commission, I visited the region of which Midland 
in Midland County is the center. This region is very dry and totally 
devoid of running water for a long distance in every direction. The 
only natural source of water-supply, a few water holes and ponds, 
were visited and found to be of such a nature that the survival of 
Simulium, far less its propagation in them, is absolutely impossible. 
The nearest stream affording possibilities as a source of Simulium.is 
60 miles away, while the average distance of such possibility is not less 
than 100 miles. 

Artificial sources of water-supply were also investigated carefully 
and were found to offer no opportunity for the breeding of Simulium. 

At Midland the histories of five cases of pellagra were obtained, 
which gave clear evidence that this place or its immediate vicinity was 
the point of origin. Persons of long residence in the country were 
questioned as to the occurrence of such flies as Simulium and returned 
negative answers. These included a retired cattle owner, who is a 
man of education and a keen observer, an expert veterinarian stationed 
in the country who has the cattle of the country under constant obser- 
vation, and a practical cattle man, manager of a ranch and of wide 
experience. The latter had had experience with “buffalo gnats” in 
other localities (in the East) and is well acquainted with them. His 
close personal supervision of the cattle under his charge, makes it prac- 
tically certain that he would have discovered these gnats had they been 
present in the country. 

At the time the study was made, Simulium was breeding and active 
in the adult state in the vicinity of Dallas, Texas, in the eastern part 
of the state. We have here a region in which cases of pellagra have 
originated, yet in which Simulinm does not and cannot breed. Dr. 


JENNINGS—STUDY OF INSECTS 17 


Sambon has suggested that in the absence of Simuliwm certain midges 
of the family Chironomidae may assume the function of transmitting 
pellagra. 

In the course of our field work, especial attention was paid to small 
flies of all kinds, and although the conditions were favorable for the 
discovery of any blood-sucking Chironomidae or other midges, none 
were collected during the two seasons spent in the field from early 
spring until late fall. 

The reports opposed to the frequent attacks of Simuliwm may be 
taken as applying also to the present group. At the risk of repetition, 
I would note that in the coast region of South Carolina, “sand-flies”’ 
are abundant, and are only too well known to the inhabitants. 

In the course of the work of 1912, we became convinced that 
Stomoxys calcitrans, the stable-fly, which had been regarded by us 
merely with suspicion, was an insect which merited the closest study in 
connection with pellagra transmission. It is practically cosmopolitan 
in distribution and is found at considerable altitudes and in high lati- 
tudes. It is an abundant species almost everywhere throughout its 
range, and in many places is a very serious pest of domestic animals. 
Under favorable conditions, there are sometimes outbreaks of this fly 
which cause the death of many animals and untold worry and suffering 
to all live stock within its influence. Primarily and by preference, it 
preys on the larger domestic animals and breeds in their excreta. 
Nevertheless, it attacks man frequently and with persistence, although 
with some irregularity, depending to a certain extent on the presence 
or absence of the animals on which it usually feeds and seemingly also 
on weather conditions. Its association with domestic animals brings it 
also into somewhat close association with man, and it readily takes up 
a more or less prolonged residence in and about human habitations. 
Ample corroboration of these statements occurs in the literature of 
the species. 

The longevity of Stomowys calcitrans in nature is not known with 
accuracy, but experimentally the fly has been kept in confinement and 
fed artificially for a period of eighty-nine days. This record was 
obtained by W. V. King in the course of pellagra transmission experi- 
ments in 1913. The average life of the flies used in the work was much 
less than this, and it is highly probable that the natural life is also 
much shorter than three months. This species frequently attacks 
several hosts during the taking of a single meal, and the habit is of 
importance in connection with disease transmission, especially when 
mechanical transference of an organism is possible. The habit seems 
to be less a matter of choice than because of the frequency with which 
it is dislodged by the animal attacked. When this occurs before the 


18 THE JOURNAL OF PARASITOLOGY 


appetite is satisfied, another spot on the same animal or another is 
selected and a fresh bite inflicted. Experimentally fed flies usually, 
when undisturbed, remain attached until the completion of the meal, 
unless the part selected is unproductive, when the proboscis may be 
withdrawn and another chosen. There is great variation in the time 
required for complete engorgement, depending apparently on the blood- 
supply of the skin at that point. On man, if applied to the lower 
extremities, a full meal may be taken in three or four minutes, while 
not infrequently the fly remains as much as fifteen minutes before 
voluntarily withdrawing the proboscis. 

In passing, it may be noted that Stomosys is purely predatory in 
its feeding habits; it is not attracted to such substances as the nasal 
secretions of animals nor to carrion or offensive substances other than 
the excreta of the larger herbivorous animals. It is reported to breed 
in the feces of hogs, but in my own experience I have not observed this. 
I have not seen them apparently attracted to hogpens nor attacking 
hogs, though they doubtless do so on occasion. This species is dis- 
tributed throughout the state of South Carolina, and in Spartanburg 
County it is very abundant. In all the cities and towns of the state it 
is present in large numbers and im the rural districts its abundance is 
even greater. Mill villages in or about which cattle are invariably kept 
are infested by large numbers of these flies and the usually unscreened: 
houses are quite regularly entered by them. That the inhabitants are 
frequently bitten cannot be doubted as the overwhelming numbers of 
reports indicate. Some individuals can almost always be found in or 
about all houses in the mill villages of the region, and a favorite 
resting place is about the porches on which much time is spent by the 
inhabitants. 

Many reports were received of attacks of Stomoxys on persons 
engaged in milking cows, and this duty falls largely on the female 
members of the household. A milk cow is kept by about one family 
in three, and the milking is done at the home of the owner to which 
the animal is brought, or in some mill villages, the cattle are excluded 
and milked and cared for in the common pasture. 

When it is recalled that a high percentage of cases of pellagra occur 
among those who spend a large proportion of their time in or about 
the home, the habit of Stomoxys in frequenting not only the interiors 
of dwellings, but those parts of their exteriors which are occupied by 
the inhabitants is important. 

Statements regarding the biting of man by Stomoxys were so uni- 
versal in our territory and were so amply confirmed by our own 
experience and observations, it must be admitted that the habit is 
frequently practiced. It shouid be emphasized that man is not attacked 


JENNINGS—STUDY OF INSECTS 19 


with the frequency and persistence displayed by such insects as the 
house mosquitoes, and it is not impossible that the distributional picture 
of pellagra may be largely accounted for by this fact. Given even a 
moderate degree of infectiousness and such a transmitter as the com- 
‘mon species of Culex, the spread of the disease could hardly fail to be 
much greater and more rapid than it is known to be. 

In addition to the reports received as to the biting habits of this fly, 
our own observations and the published statements regarding it, it 
seemed desirable to obtain, if possible, definite proof of the frequency 
with which human beings are attacked. By examination of the stomach 
contents of a large number of flies and determination of the species to 
which the host belonged it was hoped that some conclusion could be 
reached. The method adopted was the application of the precipitin 
reaction to the blood ingested by flies captured in localities where there 
would be reasonable opportunity for the selection by them of human 
hosts. More than 600 dissections were made, but the results in only 
about 200 of these are at present available. Of these, 109 were taken 
under circumstances which implied a fair chance for the fly to have 
recently attacked man, that is, in or about occupied dwellings, stores, 
etc. Six of these, or 51%4 per cent., gave a positive human reaction. 

In collecting the material no effort was made to select weather 
especially favorable for attack on man by the flies, and the days when 
captures were made it covered quite a wide range of meteorologic 
conditions. 

The number of human reactions obtained may seem small, but that 
at one period of a few minutes at each spot, such a number of flies 
were found, weather disregarded, to have recently fed on human 
beings, appears to indicate a rather free exercise of the habit. Were it 
possible to capture and test all flies within the bounds of a mill village 
for a twenty-four-hour period, and should this ratio hold, the result 
from our point of view would be startling. As a matter of fact, the 
percentage would almost certainly fall below that mentioned and yet 
would, with equal certainty, represent a large number of bites with 
their attendant possibilities of disease transmission. 

A point of interest in this series is that two of the six flies had fed 
on man only, three had fed also on cattle, while one gave a reaction 
with the sera of ox, horse and man. The blood of bovines only was 
determined in the stomachs of 80 per cent. of this series; of equines 
only, in but 6.4 per cent., while bovine and equine reaction was obtained 
in 7 per cent. The latter results are strongly corroborative of the 
observations on interrupted feeding by this species. 

It has been suggested that the bite of Stomowxys is so painful to 
human beings that but a small percentage of the flies attempting to 
draw blood from them could succeed in doing so, and that almost all 


20 THE JOURNAL OF PARASITOLOGY 


would be driven off without attaining their object. Even if this were 
true it has been shown that trypanosomiasis may be communicated by 
the mere picking of the skin by an infected Glossina, even when the 
fly is immediately removed and no blood drawn. It may be assumed 
that if the parasite of pellagra is a protozoon and Stomo.xys its carrier, 
that the same means may be effective. 

It cannot be doubted that, almost invariably, the stable fly is driven 
from its human host when the pain of the bite becomes noticeable. To 
ascertain whether blood, even in small quantity might not have, by that 
time, been drawn, a series of tests was made in which clean-bred 
Stomoxys were allowed to bite selected parts of the bodies of several 
individuals. Such parts of the extremities as are frequently exposed 
were chosen and single flies confined in flat-bottomed shell-vials 25 by 
100 mm., the end covered with gauze were applied to the bare skin, 
or in some instances the fly was allowed to bite through the stocking 
which covered the part. No hesitation was usually shown by the fly in 
proceeding to secure its meal, whether the skin was covered or bare. 
When the tube had been applied the subject was instructed to report 
the instant the first indication of pain was felt, the tube being then 
immediately removed and the fly dissected. Thirty-three flies were 
thus used, the forearm, lower leg and ankle being selected for the 
infliction of bites. In eleven instances, or 33 per cent. of the tests, - 
before pain was felt, an amount of blood was drawn which ranged 
from one-third to a full engorgement, and in five, or almost half, a 
full meal was taken. In three cases on two subjects no sensation was 
felt at any time and the fly completed its feed and withdrew the pro- 
boscis without the knowledge of the host that a bite had been inflicted. 

In many cases, the insertion of the proboscis and the early part of 
the process of drawing bk od causes no sensation. At times when the 
fly is partially engorged the proboscis is thrust deeper or its position 
slightly changed when a more or less severe prick is felt. Were the 
bite incurred under natural conditions the victim would naturally 
assume that this was the moment of attack. The wary fly, in spite of 
partial engorgement, is usually able to withdraw the proboscis and 
avoid a hasty, ill-directed slap. 

In the painless bites it is evident that anesthetic areas of the skin 
were selected, and analysis of my notes shows that one was inflicted 
one inch in front of prominence at lower end of tibia, one on external 
aspect of lower leg near median line and 6 inches above the ankle, 
the third at about the same point but 2 inches higher. This was on a 
different subject from the preceding. 

Two other full engorgements, in which some pain was felt, were 
drawn from 1 inch posterior to the prominence at lower end of tibia, 
the other from 1 inch in front of the prominence. No painless bites 


JENNINGS—STUDY OF INSECTS Zi 


were inflicted on the forearms, but five blood-meals, ranging from one- 
third to two-thirds the full feed, were drawn from approximately the 
same areas as those already indicated. 

It is of common experience that the stocking-clad ankle and parts 
of the leg adjacent thereto are favorite points of attack by Stomoxys 
calcitrans, even in the case of persons who are habitually shod. As far 
as these experiments go, they indicate that, from such parts of the 
body, an amount of blood may be drawn which by all analogy should 
be amply sufficient to cause the infection of the fly with any parasite 
present in it and capable of causing such infection. 

House-flies are everywhere excessively abundant in Spartanburg 
County, houses are generally unscreened and if pellagra should prove 
to be communicable through contamination of food, utensils, etc., this 
ubiquitous pest will probably be found to play an important part in 
the spread of the disease. 

Blow-flies are prevalent, and though far less numerous than house- 
flies, are, from their predilection for human excreta as a breeding- 
place, likely to be individually very active in such dissemination. 

The facts which have come to light regarding sewage disposal by 
means of efficient water carriage and its seeming effect on the occur- 
rence of pellagra, gives additional interest to the consideration of 
Musca domestica in this connection. Our present knowledge does not, 
however, justify a discussion of these facts or an attempt to determine 
whether the presence of sewers and the failure of pellagra to become 
active are merely coincidental and have no direct correlation ; whether 
their effect is indirect or whether the presence of this system is a prime 
factor in the control of the disease. If the latter is the case, the 
incrimination of the house-fly seems certain. 


CONCLUSION 


Our studies have led us to believe that ticks, bedbugs, mosquitoes, 
fleas, horseflies, and, in the absence of further and more incriminating 
evidence, the lice, may be dismissed from consideration as transmitters 
of pellagra; that there is not only insufficient evidence to incriminate 
flies of the genus Simulium, but much evidence directly opposed to 
such incrimination and that the biting stable-fly, Stomoxys calcitrans, 
shows in marked degree those characteristics of distribution, habit and 
association with man which would pre-eminently fit it to be the vector 
of peilagra if transmission of the disease by a blood-sucking insect is 
shown to be possible. 

If pellagra is found to be an intestinal disease of bacterial origin, 
house-flies and others of similar habits will in all probability be found 
to be an active factor in its causation. 


VARIATION IN OXYURIAS: ITS BEARING ON” Tite 
VALUE OF A NEMATODE FORMULA * 


STANLEY B. FRACKER 


University of Illinois 


One of the most difficult problems in zoologic science is the classi- 
fication of round worms. Authors and lecturers, after a carefully 
outlined and definitely arranged discussion of trematodes and ces- 
todes, are compelled to consider nematodes in a somewhat desultory 
and inaccurate fashion. Two reasons for this may be given, the 
greater being the apparent lack of a basis for determining the 
phylogeny of the major groups, a condition with which we are not 
at present concerned. The other obstacle is the difficulty of differenti- 
ating between species and uncertainty as to the value of different kinds 
of taxonomic characters. The multitude of synonyms for many of 
our common insects is a sore point among entomologists, but nemat- 
helminthologists have great difficulty in deciding that any particular 
name should be relegated to the synonymy. 

In the absence of definite structural differences, Dujardin in 1846. 
found himself compelled to give a few measurements of the length, 
breadth, tail, etc., of the species which he described. This method 
was further applied by Eberth in Germany and Bastian in England, 
followed by Biitschli and others. Finally, in 1890, N. A. Cobb 
arranged a “nematode formula” which he has applied in all his sub- 
sequent work. This formula shows two kinds of measurements: first, 
the length of the worm in millimeters; second, the percentage of that 
length which is represented by the distance from the anterior end 
of the worm to (a) the base of the pharynx, (b) the nerve ring, 
(c) the cardiac constriction, (d) the vulva, and (e) the anus; and 
also the width of the body at each of these points. He uses the 
formulae of different species, both in descriptions and in keys for 
identification. 

Cobb has described something over one hundred species of free- 
living round worms of the family Anguillulidae and has always 
worked out and stated the formula. As there are at present no 
other scientists making a specialty of this family, it would be unfair 
to emphasize the fact that, in the quarter century since the descrip- 
tion of this formula, it has been used only by its originator. There are, 


* Contributions from the Zoological Laboratory of the University of Illinois, 
under the direction of Henry B. Ward, No. 31. 


FRACKER—VARIATION IN OXYURIAS Za 


however, many helminthologists concerned with parasitic Nematoda 
where the obstacles of classification are equally great. Some of these 
have seen the possibilities of such a formula, but a real doubt as to 
its value has prevented them from adopting it. Until the following 
questions are answered, one must feel that energy and time invested 
in descriptions of this nature are not well employed: 

1. Can the formula be applied at all to the majority of para- 
sitic species ? 

2. Is the camera-lucida method of measurement sufficiently accur- 
ate for such a purpose? 

3. Are the relative proportions of the different organs constant 
within a single species? 

Cobb has not discussed these points in his published papers. He 
has applied the formula to very few parasitic species and apparently 
not at all to the difficult ones. He has published no warnings con- 
cerning the undoubted distortions caused by the varying tilt of the 
mirror, or the part of it from which a particular organ is reflected. 
In no case, so far as I am aware, does he give any indication that 
he has measured more than one individual of each species. This 
is especially noticeable in view of the fact that he must have had 
numerous specimens of some forms and that general attention has 
been called to this lack in as prominent .a place as the Cambridge 
Natural History. 

At the suggestion of Prof. Henry B. Ward of the University of 
Illinois, the writer recently undertook an investigation of the varia- 
tion in the proportion of the organs. Incidentally, fragmentary 
observations on the other two questions are reported. 

Cobb’s measurements were made on camera-lucida drawings of 
cleared worms and this procedure has been modified in only one 
particular. Most of the worms meagured by the writer were studied 
merely in formalin, only about one-fourth having been dehydrated 
and cleared in carbol xylol. None were mounted in balsam but all 
were studied under a cover-glass. The greatest care was used to 
avoid errors due to faulty technic, such as would be caused by acci- 
dental differences in the position of the camera-lucida. The effect 
of transfering the specimens from formalin to the clearing agent was 
not determined but is probably slight. The first fourteen worms 
whose measurements are reported in the table were cleared. 

The first species of which drawings were made with a view to 
measurement was the hookworm, Necator americanus Stiles. Unfor- 
tunately, this is bent in two planes, the head being hooked at a right 
angle to the general body curvature. In addition, the males, of which 
most of the available material consisted, have the anus at the tip of 


24 THE JOURNAL OF PARASTFOLOGY 


the body. The body wall is so opaque that locations of internal struc- 
ture are difficult to determine, and the writer was unable to discover 
any method of making the nerve ring visible. For these reasons 
the conclusion was reached that the formula could not be satisfac- 
torily used on these worms and work on the species was abandoned. 

Accurate measurement of larger worms, such as Ascaridae, was 
out of the question, no apparatus adaptable to this use being avail- 
able or on the market. These facts partially answer the first two prob- 
lems involved, it being clear, first, that the Strongylidae, especially the 
hookworms, do not readily lend themselves to classification by this 
means; second, that the camera-lucida method of measurement now 
in vogue is not applicable to worms exceeding 1 cm. in length. Pos- 
sibly the latter obstacle may still be overcome by the use of special 
apparatus if the formula proves its worth in other points. 

The department of zoology then secured about one hundred speci- 
mens of Oxyurias vermicularis Linn., the pinworm of man. These 
were all from one host, living in a rural locality in Kentucky, and were 
all voided at the same time. It soon became clear that, among the 
parasitic genera, O-ryurias is ideal for such work. The specimens were 
preserved in formalin, and at first the vulva could not be located with 
certainty, but clearing in carbolxylol corrected that difficulty. As a 
consequence, the writer was able to make a rigorous test of practically. 
all of Cobb’s characters except the position of the nerve ring, which 
could not be determined, owing to the preservative. It may be noted 
in passing that the nerve ring is often difficult to locate, one of Cobb’s 
largest papers (1893) omitting that character in the formulae of one- 
third of the species. Cobb gives (1890a) the formula for a young 
individual of O. vermicularis, but its immature condition invalidates 
any possible comparison with the results given here. 

The purpose of this work was not to examine critically the par- 
ticular points located by Cobb, but to ascertain the extent to which the 
proportions of the worm were constant, and the parts which undergo 
the greatest variation. The results should be of interest, both to 
parasitologists and to systematists, regardless of their relation to this 
particular formula or group. | 

The unit of measurement used was 1 per cent. of the length of the 
individual. Measurements were made on this basis from the anterior 
end (1) to the caudal margin of the cephalic swelling; (2) to the 
beginning of the esophageal bulb; (3) to the cardiac constriction; 
(4) to the vulva; (5) to the anus; (6) to the anterior and posterior 
limits of the internal reproductive organs. The width at each of 
these points was also determined. Finally, the total length of the 
worm was calculated. Fifty-two individuals were measured, but 


FRACKER—VARIATION IN OXYURIAS 25 


in most of them one character or another was so indefinite that the 
writer did not feel justified in recording what appeared to be its loca- 
tion. This was especially true of the vulva, invisible in uncleared 
material. 

The following table gives the measurements of each worm studied. 
In the first column is the arbitrary number of the specimen. The 
second gives the length of the worm in millimeters. The figures in all 
the other columns indicate the percentage of the length of the worm 
from the cephalic end to that particular point, the columns being num- 
bered as in the last paragraph. Column 6, however, shows only the 
interval occupied by the reproductive organs. “L” indicates length 
and “W” width. Finally, for each of these characters, there is 
recorded (a) the average, (b) the number of specimens on which the 
character was determined, (c) the “standard of variation,” (d) the 
maximum and (e) the minimum measurement found, and (7) the 
range. The average is the sum of all the measurements divided by (b). 
The standard of variation was calculated by the well-known formula, 


( o= a ie x being the deviation of a class from the average, and 


f, the number in the class. The range is merely the maximum, (d), 
minus the minimum, (¢). 

Attention should be called to the fact that results (a) and (c) were 
calculated from measurements to the second decimal place. In order 
to limit space it was thought desirable to omit the second place in the 
printed record. This will explain any slight discrepancies which might 
confuse, should these results be checked over. The lack of value of the 
second or even the first decimal place is discussed in a later paragraph. 

The average length of the body of this species is 7.39 mm. The 
range is about one-fourth of the maximum length. As the curve is 
normal, the total range in the species is probably not much greater 
than this. 

1. The external cephalic swelling is peculiar to the species studied 
and is a secondary development of no great definiteness or importance. 
The curve of the variation in its length is an irregular one and far 
from the normal type. It will be noted that the range is over two- 
fifths of the maximum, and that the standard of variation is 0.397 per 
cent., or about one-ninth of the maximum. In view of the nature of 
this feature, considerable variation was to be expected. 

2. The esophageal bulb marks a distinct division of the alimentary 
canal and is bounded by two definite constrictions. The esophagus, 
which leads from the mouth to this bulb, is straight or slightly bent, 
in no case being sufficiently curved to draw the bulb out of its position. 
Variation is from 8.3 per cent. to 12.1 per cent., a range of 3.8 per cent. 


Lim 


No. 


26 THE JOURNAL. iOF (PARASITOLOGY 


SAAIMTFNONDHACHAIAUMTMONDOAO 
So ele en i oe oe oe oe | 


Interval 


“AIN}S 
Phas Sez, 


60.3 
73. 
66. 

4 
58 

4 

0 


ANOMPAT KN =N SDANOMON INDAMBO’ ra ONOSH » PAE MTMGMMOSOMAMAAhy oan 
AMIAANGDAMAA to tAMmeaGmNAe TON aides PNA AM NAS . TOBA A 09 I I 09 OF OF 09 OF TIS Corr 


oO 
iva) - rNOw WOON sro COMMON LOTAQHASAMMHAAUARVONOSCANDMNTAAAN NVNa 


See TADUSAUS *SuONOT TIN DAANAAWOMNIBDSGHSONHSWCHENA OBR 
N BRON IN INN IAN ReOwnon PNAT INN RIN NIN INI AIN IND HIN DDN Wists win aon 


WINN DW Aq o21n LH 


NAGS QA +c 
TNe NIN RAINS 


18.9 


ENON ss HCOANTMH 
NORE AES NG Nae) ‘se, eREN Lr IEE ILD) es: fe.) @, cele) ‘el le; (es e% elie © lol ssi i els se 


Te Sia OO NON NOES Curlers iers/Ovuule ge! clits) fel el ihe iets, se) eel Gel tie: Velilell iehginm ie) ieigteg fe) els (olities Deliey (eles ae ae 


SHSONS Oe AMIN PtP ees BASSES Sas Seep Soret Stee tearioe) nal Sua eats ne a 
NMMNAIM MAIANANAN 


MNS rtt ST eaeiy ros strito PAN SOFA In 8 SE OVEN QTD et Dy Cy 09 U9 CO rt SEN 9D Oh SE et st et Cs: Ot Oy 202 FE OY 
wists hast fat ued itiesinst twee FL Od 09 aE 09 09 OF OF ALN SE 0G Ov OF SF 0 09.09 03 09 EEA 09 CO TON 


= 


ONODHNA PEOTANMSCOAANTADAAIADAIOMONAHROMAAN Lr4re 


TTtNON Im OnNNR ROTO jim dats SAAN “tor 
raneri SS eS Se eee See ee See eS see ee 


NoNwMnrdts Sart . 


OO 
ANNAN fs finn 
Se I eB ce ee eB oe Be oe ol — 


ie) 


IX 
DIINNAK DAN Ow DAD OD rOTAMIMAGNOD TOMMAOCONMATFOCMHANDMDNAUDHDSOHAGCOON Aen 


tat taaes aa+ it Pact PSO HHI GAMA AM OMAN MAINT HAKAN tH wn ies 
— 


x 


WMONAMTEAGTAN HD s sOOMD AAI AIAMNAT TY MMOON CONDON NR DOOM OOMANOMOW CO Rama 


ASAAARSSAK "Awe ‘S LOW SSANHOHASHODAAAAAAS ASAT ACSANRLABASOAAY Nes 
oe ae : mm Se De nw onl 


= 


OOM OPAL 0910 19 rt FO 5 09 0G 1N FO OIN O41 01 tODMNAVDAOH bd sOQMHMOMNOCHNM NY Boon 
ANNANAAN SANNA ANNAANNAANNAIANNANN OA OS sae AA Se PAA A tt cd OF ATO Aine 


mm, 


MN 


a 
A NEN MSTA CHE NMHC MIN ON 1 FO Ses SO LNHOANAQAMIS soe TDR OTAAVHON TANS MeyAawo 


ANAM BANMANANN NAAN AAA Aled TAM ANAS A PAALN AAA ANAC Nedeiog As 


TAMTFOOMNMANOHMMOMOANRANOMONTHONRAUNTMHOMWOMNMOOSCS 
DTA DAAAAEMIMODHAOCHTHOCOMMOCDNMIMMAEANGCOAMOTANM 
N OND 


OMNONNRDOUMNUORRONRUONUONUONRONNONNRORONNNN OO 


eee 


tee 


No. 


FRACKER—VARIATION IN OXYURIAS 27 


The magnitude of the range and of the standard of variation is 
striking. 

3. The cardiac constriction is the caudal limit of the esophageal 
bulb, which occupies from 2 to 3 per cent. of the length of the worm. 
The distance of this constriction from the mouth varies from 10.4 to 
14.4 per cent., and the range, 4 per cent., is about two-sevenths of the 
maximum. This range overlaps about one-sixth of all the species Cobb 
has described in the papers at hand. 

4. Only thirteen individuals were studied in which the vulva could 
be located, it being invisible in the opaque formalin material. In the 
cleared specimens, the range in its position was about one-third of the 
maximum distance from the mouth. The standard of variation, 3.37 
per cent., is over four times that of any of the first three structures. 


Fig. 1—Oxyurias vermicularis Linn. Specimen No. 2; lateral aspect of 
cleared worm. 1-6, the structures and distances measured in this paper; for 
explanation see text, and table opposite. 


5. The anus is usually located in the caudal fourth of the body, its 
position varying from 74.2 to 81.4 per cent., a range of 7.2 per cent. 
The standard of variation is 1.78 per cent., or midway between those 
of the last two structures. Some reliance, therefore, can be placed on 
measurements of the location of the anus. 


6. In the use of the formula, the interval occupied by the repro- 
ductive organs is given in an approximate and general way. Cobb 
usually uses a multiple of 10 per cent. to express this distance. Even 
this approximation, however, appears to be of no value in Ovyurias. 
In some cases these organs reach from a point near the mouth (5.7 per 
cent.) to a point behind the anus (86.9 per cent.), often obscuring the 
latter’s position. In other specimens they have shrunken to a small 
size or are undeveloped. The interval occupied varies from 37.5 to 
75.1 per cent., a range of 37.6 per cent. Such a condition makes the 
recording of this interval in the specimens at hand when a species is 
described a waste of labor. 

While measurements of the lengths of different structures vary 
independently of each other, this is not true of the widths at different 
points. For this reason separate discussions of the latter are not 
necessary. In almost all cases the range in widths is approximately 
equal to, or greater than, the width of the most slender worm studied. 
So few specimens were measured at the vulva that the range there is 


28 THE JOURNAL’) OF PARASITOLOGY 


not as great as it should be, neither the slimmest nor plumpest worms 
having been measured at this point. Taking the width at the cardiac 
constriction as typical, we find a variation of from 2.4 to 6.3 per cent. 
The latter worm was particularly contracted, however, the normal 
range being from 2.4 to 5.4 per cent., as shown by the curve of 
variation. 

If structures were correlated with each other, considerable reliance 
could be placed on the body proportions in spite of the individual 
variation. It was hoped that a study of correlation would yield results 
which would assist in the interpretation of the relation between an 
unnamed specimen and a given formula. The attempt to find such 
assistance, however, must be considered a failure. 

Correlation diagrams were made to show the relation of the width 
of the body to the length of the esophagus, the length of the alimentary 
canal to the length of the esophagus, the relation of the position of the 
vulva to that of the anus and to that of the cardiac constriction, etc. 
In no case was there the least indication of correlation, except between 
the length of the esophagus and the position of the cardiac constriction. 
As the esophageal bulb which separates these is small and rather con- 
stant in size, this fact can hardly be called a true correlation. 

Much of the importance of a study of variation in its relation to 
classification depends on the differences between the various species. 
with the group concerned. Thus, if all Nematoda had an esophagus 
about one-eighth the length of the body, had the vulva placed within 
the cephalic third, and the anus near the beginning of the caudal fourth 
of the total length, a variation no greater than occurs in Oxsyurias 
would make the measurement method valueless in identification. The 
formulae of about one hundred species described by N. A. Cobb were, 
therefore, examined in order to determine the variation within the 
class. In some. cases curves were plotted. 

This examination showed an ideal condition for such a scheme. 
A curve including the formulae of the described species is similar to 
a long, low mountain range. All possible changes in the proportions 
seem to have been observed. As a result, the range of each of the 
characters given above covers only one-fifth to one-tenth of the 
described species. In some cases it is less than that. For example, 
the vulva, in the eighty-five species whose descriptions happen to be 
before me at the moment, varies from 20 to about 80 per cent. in posi- 
tion. Of these, only five species are between the maximum and mini- 
mum found in the specimens of Owyurias reported in this paper. 
Forty of them, however, or nearly half, are between 45 and 55 per 
cent., a range less than that in this species. The fact, therefore, that 
the range appears unimportant in this case seems to be an accident of 
the species chosen. 


FRACKER—VARIATION IN OXYURIAS 29 


In tables for identification, Cobb has used such characters as “Tail 
15 per cent.,” as opposed to “Tail 20 per cent.”; or “Body slender 
(little more than 2.6 per cent.)” in opposition to “Body not so slender 
(3 per cent. or over).’’ In these and many other places the difference 
specified is less than the range in this one species. 

In general, the variations recorded here may be due to two causes: 
(a) varying state of contraction owing to chemical technic, conditions 
of killing, etc., and (b) ordinary fluctuating variations. ,General body 
contraction would not affect the positions of the organs and can 
scarcely account for differences in length percentages. On the other 
hand it would have an important effect on the width. Thus the length 
percentages, depending largely on fluctuating individual variations, are 
not correlated with the widths, most of which are determined by the 
state of contraction. The impossibility of securing uniform con- 
traction makes it necessary to consider width measurements unreliable. 

In the practice of identification of specimens two advantages may 
be claimed for a formula. In the first place’ it is an abbreviated record 
of what would be a long description. This advantage cannot be gain- 
said and is the principal source of the strength of the “nematode for- 
mula.” In the second place a comparison of the formula of a speci- 
men at hand with those of a series of descriptions might aid in identi- 
fication. This is the advantage which has been emphasized too much. 
The following are the formulae of a few of the specimens of Oayurias 
vermicularis: 


22 9.5 ez 2A Hi. 

RN UL, ee (5) Sa. 
2.6 48 Br 6.4 3.1 
2.4 10.0 1253 Ware 79.5 

No: 2) eS 7.07 tm: 
2.0 $5 ae Be Sue, 

2.9 10.9 13.4 ou 74.5 
eC TTT 
2a 3.9 4.3 ? 3.1 
Syl 9.9 122 Gey 80.6 
INO, ZAG a NES Sra 
2.1 32 B85 ? 3.6 
2.8 9.0 ial ee 81.2 
NG, 5) rT 
2.0 2.9 a2 ? 2.4 


These figures do not refer to the exact points used by Cobb, but 
the principle is the same. If the species had been described from No. 7 
and that formula given as typical, it is doubtful whether it would aid 
in naming No. 26 or any of the others. 


30 THE JOURNAL (OF PARASITOLOGY 


CONCLUSIONS 


The proportionate size of the organs in Nematoda is an important 
factor in their identification and should be stated in any description of 
a new species. 

The locations of the cephalic parts of the alimentary canal tend to 
vary from 1 to 4 per cent., about one-third of the maximum, in O.ry- 
urias vermicularis. 

The location of the vulva probably varies at least 15 per cent. in a 
long series of individuals. 

The location of the anus varies over 7 per cent., or about one-third 
of the length of the tail. 

Variations in width are so great that some individuals are over 
twice as wide as others. 

The length of the body of some individuals is one-third greater 
than that of others. 

The use of the formula is likely to yield more confusion than assist- 
ance. It is impossible to indicate the observed range, and without that 
the numbers are meaningless. Carrying the measurement to one-tenth 
of 1 per cent., gives an appearance of accuracy which does not exist. 
The formula is likely to result in the multiplication of so-called species 
without a proper basis for their separation. 

A species should not be described as new on account of a deviation 
from the proportions of known species unless that deviation is great 
and fundamental. The space occupied by the reproductive organs 
should not be considered, and little dependence should be placed on the 
width of the body. From four to ten individuals should always be 
studied and the observed range recorded. In this way the varying 
proportions of the different species can be used in the identification of 
collected specimens. An individual should never be identified, how- 
ever, on the basis of the formula alone or of the proportions alone. 


REFERENCES CITED 


Cobb, N. A. 1890. A Nematode Fermula. Agr. Gaz., N. S. W., 11:131-135. 

1890a. Oxyuris Larvae Hatched in the Human Stomach under 
Normal Conditions. Proc. Linn. Soc., N. S. W., 5: 
168-185. 

1890b. Arabian Nematodes. Proc. Linn. Soc. N. S. W., 5: 
449-468. 

1893. Nematodes, Mostly Australian and Fijian. Dept. Agr., 
N. S. W., Mise. Publ. 13, 59 pp: 

1902. The Nematode Fermula. Agr. Gaz., N. S. W., 13:1023- 
1030. 

1913. New Nematode Genera Found Inhabiting Fresh Water 
and Non-Brackish Soils. Jour. Wash. Ac. Sci., 3:432- 
444. 


OBSERVATIONS ON) THE EGGS “OF ASCARIS 
LUMBRICOIDES 


WintuHrop D. FOSTER 
Junior Zoologist, Bureau of Animal Industry, U. S. Department of Agriculture. 


The appearance of the ova of Ascaris lumbricoides as seen in fresh 
feces is so well known to physicians and zoologists that description is 
unnecessary. Occasionally, however, ascarid eggs are found which 
differ so widely from the normal egg of Ascaris lumbricoides as to 
cause considerable confusion on the part of observers, and may even 
be so misleading in appearance as to be attributed to another species. 
One of these atypical forms, the unfertilized egg of Ascaris lumbri- 
coides, first reported by Miura and Nishiuchi (1902), is by no means 
rare, and is usually seen in the feces of persons infested with female 
parasites only (Fig. 1). 


Fig. 1—Unfertilized egg of Ascaris lumbricoides. After Miura and Nishi- 
uchi, 1902. 


Another atypical egg, differing from the normal egg only in size, 
has an exceptionally long major axis, while its width is no greater than 
that of the average egg, thus giving it a narrow elliptical form instead 
of the broad oval of the average egg. A sample of feces received from 
Florida contained numbers of eggs of this form, no eggs of average 
size being present. In this case the variation from the normal egg was 
so marked that it was only after having observed similar eggs known 
to have come from Ascaris lumbricoides, I could be certain of the 
identification. Although not reported in the literature, except for a 
brief note by the writer (Foster, 1913), this type of ascarid egg is 
apparently not rare. Drs. Stitt and Garrison, in conversation with the 
writer, reported seeing this atypical form in feces in Manila, while 
Dr. Stiles told the writer that he had seen several cases while engaged 
in hookworm work in the Southern states. The appearance of the 


32 PHE- JOURNAL, OF, PARASITOLOGY 


elongated egg contrasted with the normal egg is shown in Figures 2 
and 3. 

As the result of the measurement of over 200 eggs, half of which 
were derived from dissections of ascarids from man and half from 
ascarids of pigs, I find that there is no sharp demarcation between the 
excessively long egg and the average egg, but specimens can be found 
making a complete series. By averaging all eggs having the same 


Yoommi. 


Fig. 2—Superficial view of eggs of Ascaris lumbricoides. a, normal egg; b, 
elongated form. 


length but different diameters, and arranging the results in the order 
of increasing length, it was found that the diameter remained fairly 
constant as the length of the egg increased. It follows as a corollary 


Fig. 3—Eggs of Ascaris lumbricoides seen in optical section. a, normal 
ege; b and c, elongated forms. 


that as the length of the eggs of Ascaris lumbricoides increases, the 
ratio of the diameter to the length steadily decreases. This rule was 
found to apply both to those eggs derived from ascarids from swine 
and to those from man. There are of course many slight exceptions 
to this rule, but if a sufficient number of eggs are measured to serve as 


FOSTER—EGGS OF ASCARIS LUMBRICOIDES 33 


a fair basis of comparison, it will be seen that but little variation is 
found in the diameter of the eggs measured, while the length may vary 
throughout a range of 51 microns between the shortest and longest 
egg. When ratios are considered, instead of actual measurements, the 
exceptions to the corollary of the rule are very few, since individual 
variations are largely neutralized when expressed in terms of relative 
values. 

The accompanying diagram (Fig. 4) shows how little variation is 
seen in the diameter of ascarid eggs, compared to the great variation in 
length. In the left-hand column, representing measurements of ascarid 
eggs from swine, there is a variation of 29 microns between the maxi- 
mum and minimum length, although both extremes have the same 
diameter, which is only 7 microns less than the average diameter of all 
eggs measured. In the right-hand column, representing the longest 
‘and shortest egg seen in ascarids from man, there is a difference of 
51 microns between the maximum and minimum lengths, while the 
diameter of the longest egg is actually 8 microns less than that of the 
shortest egg and is 12 microns less than the average diameter of all 
eggs measured. 

The fact that all eggs, no matter what their length, have a fairly 
uniform diameter, would seem to be based on some morphologic struc- 
ture of the female genital tract. If at some point in their development, 
the eggs, while still in a plastic condition, were forced lengthwise 
through a narrow lumen admitting only one egg at a time, we should 
expect to find all the eggs of a given worm having approximately the 
same diameter. It is evident that this modification cannot take place 
in the vagina, for although eggs usually pass out of the vagina in single 
file, dissection of the uterus shows the extremely long eggs and average 
eggs all having approximately the same diameter, in the proximal 
portion of the uterus before the eggs have passed through the vagina. 
Besides, the muscular wall of the vagina will expand to accommodate 
itself to the different diameters of the eggs rather than force them to 
conform to its own diameter, since the chitinous shell allows of very 
little if any compression. The modifying influence, if any such is 
present, must therefore be exerted at some point in the genital tract 
before the egg receives its shell, or while in the process of shell forma- 
tion. As Leuckart (1867) calls attention to the fact that eggs in the 
posterior uterus before their shells are fully formed have approxi- 
mately the same diameter though varying in length, it occurred to the 
writer that this modifying influence might take place as the eggs pass 
from the receptaculum seminis, the region immediately posterior of 
the uterus, into the uterus. The receptaculum seminis is separated 
from the uterus by a narrow sphincter-like constriction described by 


34 THE JOURNAL OF PARASITOLOGY 


STOM stline TTOM TAN 


b b 


Fig. 4—Diagram based on measurements of over 200 ascarid eggs from 
man and from swine, illustrating the principle that the diameter remains fairly 
constant as the length of the eggs increases. a, eggs of maximum length, from 
swine and from man respectively; b, eggs of average length; c, eggs of mini- 
mum length. 


FOSTER—EGGS OF ASCARIS LUMBRICOIDES 35 


Leuckart (1867) and at this point the eggs are still plastic, as they do 
not receive their shells (according to Blanchard, 1888) until the eggs 
have traversed the posterior half of the uterus. Cross-sections of this 
sphincter, however, show that its lumen, while considerably narrower 
than the preceding or subsequent parts of the genital tract, is suffi- 
ciently large to allow many eggs to pass through at one time. The 
writer has examined cross-sections of the entire posterior half of the 
uterus without finding any place where the eggs when in a plastic 
condition would be subjected to pressure tending to give them a uni- 
form diameter. 

While the uniform diameter of eggs from the same worm may be 
explained by some such morphologic modification as suggested above, 
it is harder to explain the fact that eggs from different worms varying 
greatly in size, have approximately the same diameter. It is hardly 
reasonable to assume that the lumen of the genital tract in different 
worms would have approximately the same diameter at the same place, 
for since the external measurements of different adult individuals is 
subject to great variation, we should expect and in fact do find, corre- 
sponding variations in the measurements of the internal organs. 


Table of measurements of eggs of Ascaris lumbricoides from man and 
from swine, arranged in order of decreasing length, to show that as the length 
decreases, the width remains constant or slightly increases. Measurements in 
microns. Each set of measurements represents the averages of five individual 
eggs from the same worm. In those cases where the measurements have the 
same length but different widths, the corresponding ratio is the ratio of the 
average width to the given length. 


TABLE 3.—CoMBINED FROM 
TABLE 1—From Swine TABLE 2.—From Man | Once ange ine 
Length | Width Ratio Length | Width Ratio | Length Width | Ratio 
73.0 56.5 ) 7] 87.5 49.0 56.0 87.5 49.0 56.0 
73.0 49.0 § : 78.0 46.5 78.0 49.5 63.5 
70.5 51.5 713 78.0 Bills 63.5 755 57.5 76.2 
70.5 49.0 ; 78.0 50.5 73.0 54.0 74.0 
68.0 56.5 755 Lys Wh aaa 71.5 55.5 77.6 
68.0 54.0 81.3 73.0 Foye) | 75 3 71.0 Bie5 125 
68.0 56.5 73.0 54.0§ | : 70.5 51.0 72.3 
66.0 Stone (3/65 71.5 Bn) | 77.6 69.0 49.0 71.0 
65.5 49.0) | 71.0 51.5 72.5 68.0 53.0 77.9 
65.5 54.0 81.0 70.5 Giles | YO 66.0 50.5 76.5 
65.5 56.5 69.0 49.0 | 71.0 65.5 51.0 779 
64.5 45.0 69.7 68.0 51.5 } | 73.4 65.0 54.0 83.1 
63.5 47.5 726 68.0 49.0 ; 64.5 49.0 76.0 
63.5 45.0 : 65.5 | 48.5 | 74.0 63.5 49'5' oI) 978.0 
62.5 52.5 | 84.0 65.0 54.0n e830 62.0 51.0 82.3 
62.0 49.0 | 79.0 64.5 52.5 81.3 61.0 47.5 77.9 
61.0 47.5 778 63.5 RoE Ea 73.2 56.5 46.5 82.3 
56a. |- 465 | gag.) | Magignriaigia cle eae 
| 62.0 530) oe) ees. 


36 THE JOURNAL OF PARASITOLOGY 


REFERENCES CITED 


Blanchard, R. 1888. Traité de zoologie médicale. 1: 481-808. 

Foster, W. D. 1913. Some Atypical Forms of the Eggs of Ascaris lum- 
bricoides. Science, n. s. 37: 78. 

Leuckart, R. 1867. Die menschlichen Parasiten und die von ihnen herrthr- 
enden Krankheiten, v. 2, 1. Lief. 

Miura, K., and Nishiuchi, N. 1902. Ueber befruchtete und unbefruchtete 
Ascarideier im menschlichen Kote. Centralbl. f. Bakt., Abt., Orig., 32: 637-641. 


DR NOES THHORMOR INSECT ‘CAUSATION OF 
DISEASE 


WittiAM A. RILEY 


Cornell University. 


The danger in using isolated sentences from an article as a basis 
for interpreting the author’s theories, is generally recognized, but 
sometimes the most careful workers fall into the trap. Once the mis- 
taken interpretation is published, it may be copied over and over again 
until it rises to the dignity of a dogma. 

A striking illustration is afforded by the practical unanimity with 
which writers on the subject of insects and disease credit Dr. Josiah 
Nott with being the earliest to formulate definitely the theory of mos- 
quito transmission of yellow fever. 

Nuttall, in his classic monograph “On the Role of Insects, Arach- 
nids and Myriapods as Carriers in the Spread of Bacterial and Para- 
sitic Diseases” (1899), states: “In 1848, Nott of New Orleans pub- 
lished an essay on yellow fever, in which he refers to malaria as if the 
mosquito theory had already been advanced, and he gives grounds for 
his belief that the mosquito also gives rise to yellow fever.” 

The original publication was not accessible to Dr. Nuttall, who was 
forced to depend on an abstract furnished by Dr. Isadore Dyer of 
New Orleans. Following Nuttall, almost every writer on the historical 
aspect of the theory of insect transmission of disease, especially 
yellow fever, refers to Nott’s theory, and some who have evidently 
seen and hurriedly read the original, quote specific statements which 
seem to indicate clearly the intent of the argument. 

Dr Nott’s scholarly paper on “The Cause of Yellow Fever” was 
published in the New Orleans Medical and Surgical Journal, vol. iv, in 
March, 1848. A cursory reading of it, in the light of. present-day 
knowledge, affords ample indication that he believed in the insect 
transmission not only of yellow fever, but also of malaria and various 
other diseases. For instance, one could hardly draw any other con- 
clusion from reading such isolated statements as: 


“The morbific cause of yellow fever is not amenable to any of the laws of 
gases, vapors, emanations, etc., but has an inherent power of propagation, 
independent of the motions of the atmosphere, and which accords in many 
respects with the peculiar habits and instincts of insects. 

“There are even perfectly authenticated instances where one side or end 
of a ship has suffered severely from the disease while the other was entirely 
free from it. We can readily believe that certain insects which are endowed 
with unaccountable instincts and habits, might attack a part of a ship, of a 


38 THE JOURNAL OF PARASITOLOGY 


tree, of a wheat or cotton field, but we cannot imagine how a gas could be 
turned loose on one side of the cabin of a vessel and not extend to the other. 

“It would certainly be quite as philosophic (as the malarial theory) to 
suppose that some insect or animalcule hatched in the lowlands, like the mos- 
quito, after passing through its metamorphosis takes flight and either from a 
preference for a different atmosphere, or impelled by one of those extraordi- 
nary instincts which many are known to possess, wings its way to the hill top 
to fulfil its appointed destiny.” 


Explicit as these statements seem, they can be interpreted only 
when we remember that Nott wrote at a period before Pasteur and 
Koch had completely revolutionized the ideas of medical men regard- 
ing the causation of disease, and that he was in reality presenting a 
masterly argument in favor of a germ theory of disease. No one can 
read the entire article, in its proper historical setting, without realizing 
that Dr. Nott used the term “insect” to denominate micro-organisms, 
and that his explicit references to true insects were merely for the 
purpose of illustrating the propagation, methods of development and 
habits of the invisible “insects” or ‘“animalcules” whose existence he 
postulated. 

He did speak of “the perfect analogy between the habits of certain 
insects and yellow fever,” but he had no more intention of urging that 
the disease was mosquito borne than that it was carried by the aphids, 
Hessian flies or cotton worms that he also cites for illustration. 

If, after reading the full article, additional evidence is desired, it is 
furnished in a conclusive manner by going still further back. Dr. Nott 
takes pains to explain that “there is no novelty in the doctrine of the 
insect or animalcule origin of disease’ and states that “the most 
elaborate and ingenious article I have met with is that in Sir Henry 
Holland’s Medical Notes, “On the Hypothesis of Insect Life as a Cause 
of Disease.” 

On referring to that interesting book, printed in 1839, we find that 
Dr. Holland raises the question as to “what weight we may attach to 
the opinion that certain diseases, and especially some of epidemic and 
contagious kind, are derived from minute forms of animal life, existing 
in the atmosphere under particular circumstances.” 

His use of the term “insect” is illustrated by the statement: 


“Tt is only of late that the wonderful eye of the microscope has clearly 
disclosed to us that vast domain of life to which the infusoria belong; a 
new world which might have remained forever as much hidden from our 
sense and knowledge as the invisible forms of insect life, of which the 
hypothesis before us presumes the existence. 

“Tf existing, the same analogy will lead us to other inferences, not less 
probable, as to those habits and instincts, in which they may be presumed to 
have affinity for the known insect genera. Such are their frequent sudden 
generation, at irregular and often distant periods, under certain circumstances 
of season or locality, or under other conditions, less obvious to apprehension. 
Secondly, the diffusion of swarms, so generated, and with rapidly repeated 


RILEY—NOTTS THEORY OF DISEASE CAUSATION 39 


propagation, over wide tracts of country, and often following particular lines 
of movement. To which general inferences may be added another (resting on 
analogy, though of less explicit kind), namely, that certain of these animalcule 
species may act as poisons, or causes of disease. 

| “Whatever is true as to the habits of insects obvious to-our senses, is 
likely to be more especially so in those whose minuteness removes them further 
from observation.” (Italics mine.) d 


It was to the support of this hypothesis of causation of disease by 
micro-organisms and this alone, that Nott brought a wealth of observa- 


tions on yellow fever and malaria, and he deserves full credit for the 
logical manner in which he analyzed and presented his data. 


RHABDITIN 


CONTRIBUTION TO A SCIENCE OF NEMATOLOGY 


N. A. Coss 


Agricultural Technologist, U. S. Department of Agriculture, 
Bureau of Plant Industry. 


Rhabditin is the term applied by the writer to an organic substance, 
the type form of which is found crystallized in brilliantly doubly 
refractive spheres arranged in‘a definite way in the cells of the intestine 
Rhabditis monhystera Bitschli, and other nematodes, in whose metab- 
olism it plays an important role. 

Rhabditin crystallizes under the life influences of Rhabditis mon- 
hystera into spheres, about 1 to 3 microns in diameter, which are rather 
slowly soluble in water, rapidly so in alkalies and acids — in the latter 
without effervescence — and are insoluble or but very slowly soluble 
in alcohol, glycerin, xylol and oils. The aqueous solution gives no 
precipitate with barium chlorid or barium hydrate. The crystals do 
not change essentially in optical properties (do not melt or dissolve) 
when the nematodes are fixed in boiling absolute alcohol. 

When disintegrating in water the internal parts of the spheres first 
dissolve, leaving in the course of five to thirty minutes shells (plasts?) 
which are not doubly refractive, and which stain readily and strongly 
in solution of gentian violet, less strongly in aqueous safranin. The 
crystals, when freshly removed from the tissues of the nematode and 
placed immediately in the violet, while strongly stained externally, do 
not appear to be stained in the internal doubly refractive part, the 
“maltese cross” of which appears brilliant and unstained when viewed 
with crossed Nichols. Rhabditin does not stain in iodin-potassium- 
iodid solution. 

In a microscopic test the crushed bodies of Rhabditis monhystera 
reduced Fehling’s solution, and it seemed probable that rhabditin was 
the main if not the sole reducing agent. 

When the spheres are undergoing brownian movements they prove 
to be doubly refractive in every view, though the maltese cross occa- 
sionally “blinks,” as if in one particular direction this property is less 
pronounced. 

In Rhabditis monhystera the crystals of rhabditin are arranged in 
relatively large groups round the centrally located nuclei of the intes- 
tinal cells, and sometimes constitute a large fraction of the mass of 
the cells. They are absent, or infrequent, in the initial intestinal cells 


Female 
Section of 
rhabditin. 
maltese cr 
rhabditin | 
vard. WV 


various Sizé 
1, lips; 
terior portion of esophagus; 


rectum); 


oss remains undiminished in brilliancy even 


hystera Butschli viewed with polarized light. 


Rhabditis mon 
worm more highly magnified, 
III and IV. Crystals of rhabditin in process of solution in 


1as been dissolved, indicating that the solution takes place 


I. 


and VI. Crystals of rhabditin showing the comparative appe 


when seen without polarized light. 
bulb; d, nerve-ring; e, cardiac 


b, pharynx; c, median 
ure in ovary; 


h, excretory pore; 1, flex 


yN11s 
ius. 


bulb; 


showing intestinal cells, their nucl 
Wa 


when a large 


froi 


I 


] t 

1 

l 
Note 
portior 
he é 
estine 


COBB—RHABDITIN 41 


— the few immediately behind the cardia. They may be found in each 
of the other cells of the intestine, but are then likely to be a trifle less 
numerous in the final cells. They do not occur in any other cells of 
the body. In some other species they occur less generally, sometimes 
only ina part of the intestine, and sometimes as “double” spheres. 

When the bodies of Rhabditis monhystera are incinerated no trace 
of rhabditin remains; when the bodies containing a large amount of 
rhabditin are burned in a Bunsen flame in front of the spectroscope, 
only a very faint flickering sodium band is to be seen, indicating the 
absence of the earthy constituents that might be expected in certain 
excretory salts, for example, calcium. 

From the foregoing tests it will be seen that the present indications 
are that rhabditin is a carbohydrate, though it seems out of harmony 
with this supposition that the crystals do not decrease materially in 
number or size when the nematode containing them is placed on a 
starvation basis in distilled water for seven days. During this time 
other granules in the same cells, believed to be fatty substances, dis- 
appear. Its isolation in sufficient quantity for more complete tests will 
be a difficult matter. 

Rhabditin occurs in embryos, even very young ones, in compara- 
tively early stages of their segmentation, and the future intestinal cells 
may sometimes be distinguished from other cells by what appear to be 
exceedingly minute crystals of rhabditin. 

Rhabditin has been noted by various investigators under the name 
of “granules,” for the most part merely so indicated in dtawings, 
without comment, except where indicated merely as a means of species 
characterization. 

With the crystals of rhabditin there often occur other granular 
bodies of a different nature. 


EXPERIMENTAL INGESTION BY MAN OF CYSTICERCI 
OF CARNIVORE TAPEWORMS 


Maurice C. Hai 
Assistant Zoologist, U. S. Bureau of Animal Industry. 


Having experimentally eaten the larvae of dog tapeworms on two 
occasions, I undertook to look up the literature on this subject in con- 
nection with the ingestion of Cysticercus pisiformis to check the fre- 
quently quoted record of 7. pisiformis from man. I find that there 
are more cases of the sort than I had supposed, so I have collected 
these cases in connection with a recent similar case of my own. 

Taenia pisiformis, under the name of T. serrata, has been recorded 
as a parasite of man by Vital (1874), who records, in effect, two 
cases. One was a case of intestinal taeniasis in a native Algerian, 
reported under the paragraph heading (translated) Two taenias in the 
digestive tract, one of which has the appearance of Taenia serrata. 
These tapeworms were collected post mortem. He states that one 
tapeworm was undoubtedly 7. solium. The other was 1 meter long 
and 6 mm. broad, the segments attached in such fashion as to present 
a saw-toothed aspect. The thick rostrum was armed with hooks, and 
a single lateral genital pore was noted in the segments. There are no 
further data on this case. 

A footnote reference states that 7. serrata has recently been col- 
lected at Constantine (the locality for Vital’s case also) in company 
with two specimens of 7. saginata from a young woman by the use of 
pumpkin-seed as a vermifuge. Parenthetically, he remarks that the 
worms were examined by Dr. Cauvet. Two months later, Cauvet pub. 
lished in the same journal (Gazette médicale de Paris) a note on the 
tapeworms found in Algeria. In this note he lists and discusses 
Bothriocephailus, T. solium and T. saginata. He says nothing whatever 
about 7. serrata, and it seems safe to assume that any statements he 
may have made regarding a worm from man being T. serrata were not 
based on careful examination and were not intended for publication. 

It is quite impossible to identify 7. serrata by any such casual 
method as Vital used. Parasitologists who have mentioned Vital’s 
cases have regularly regarded them as doubtful or erroneous. Moniez 
(1896) states that neither Vital nor Cauvet can be considered as 
authorities. He adds that he has fed Cysticercus pisiformis to two 
volunteer human subjects without developing the tapeworm.  Galli- 
Valerio (1898) states that he once ingested six of these larvae. This 
occasioned a slight stomachache that night, possibly due to toxins in the 


HALL—INGESTION BY MAN OF CYSTICERCI 43 


cysticerci, but no tapeworm development was noted in spite of fecal 
examination and the use of male fern as a vermifuge. During the 
summer of 1913 I ingested three Cysticercus pisiformis collected from 
a freshly killed rabbit. I did not ingest any of the cyst fluid and had 
no discomfort. There have been no indications of tapeworm develop- 
ment. 

In view of the fact that ingestion of Cysticercus pisiformis by four 
persons has not resulted in tapeworm development in any case, and 
that Vital’s and Cauvet’s records show obvious evidence that there 
were no grounds for Vital’s statement, it seems evident that his record 
of T. pisiformis should be distinctly characterized as erroneous. 

Multiceps serialis has never been claimed as a parasite of man. 
Galli-Valerio (1909) states that he has eaten two larval scolices, and 
I recorded in 1910 the eating of three such scolices. No tapeworms 
developed in either case, indicating that the parasite will never be 
found as an accidental parasite of man. In passing, it may be said 
that on the face of it there would seem to be more likelihood of this 
parasite, which is frequently imbedded in the connective tissues in the 
edible musculature of the rabbit, functioning as a parasite of man than 
there is in the case of T. pisiformis where the fully developed larva is 
found among the inedible viscera. 

Taenia teniaeformis has never been recorded as a parasite of man, 
but Krabbe (1880) has called attention to the fact that in Jutland, mice 
are sometimes chopped up, spread on bread and eaten raw as a folk 
remedy for retention of urine, and has suggested that this might lead 
to infestation with the adult worm. Moniez (1896) states that he has 
fed Cysticercus fasciolaris to his two volunteer subjects noted above 
without producing the adult tapeworm. 

Taenia krabbei is another carnivore tapeworm that has not been 
reported from man, though its occurrence in the edible meat of an 
important food animal would indicate the likelihood of its occurring in 
men. However, Moniez (1896) states that his volunteers have ingested 
the larvae of this tapeworm without results. 

Taenia tenella was surmised by Cobbold to be a human tapeworm 
arising from Cysticercus ovis in the meat of sheep. Railliet (1885) 
notes that Chatin has on several occasions ingested Cysticercus ovis 
without giving rise to a tapeworm, and Ransom (1913) states that he 
has ingested ten of these larvae without result. The tapeworm pro- 
duced by feeding Cysticercus ovis to dogs was considered by Chatin to 
be T. hydatigena, but Ransom (1913) has shown that it is a distinct 
species of carnivore tapeworm, Taenia ovis. The fact that Taenia ovis 
and Taenia krabbei, both with larvae situated in the edible musculature 
of important food animals, seem incapable of developing in man, is a 


44 THE JOURNAL OF -~PARASITOLOGY 


further argument against the likelihood of such a tapeworm as T. pisi- 
fornus, with larvae in the inedible viscera, developing to an adult tape- 
worm in man. 

Taema hydatigena and Multiceps multiceps have never been 
reported as intestinal parasites of man. This is not surprising, in 
view of the size of the larvae and site of infection for the larvae. It is 
further likely that if they were present the former would be taken for 
T. solium and the latter for the more common T. pisiformis. I have 
found no records of the ingestion of the larvae by man, but Stiles 
(1898) states of the larvae of 7. hydatigena, “Although several authors 
have attempted to infect themselves with tapeworms by swallowing this 
larvae, all such attempts have been negative.” 

The facts noted above indicate the correctness of the generally 
accepted view, that adult cestodes of the genus Taenia occurring in 
carnivores do not occur in man. The converse of this proposition is 
also true. 


m PECULIAR MORPHOLOGIC DEVELOPMENT OF AN 
EGG OF THE GENUS TROPIDOCERCA AND 
ITS PROBABLE SIGNIFICANCE 


WintTHRop D. FOSTER 


Junior Zoologist, Bureau of Animal Industry, U. S. Department of Agriculture. 


The accompanying drawing represents the egg of a species of 
Tropidocerca from the proventriculus of an American woodcock 
(Philohela minor) shot at Bowie, Md., Nov. 11, 1912. A comparison 
of the specimens found, with the different species descriptions, shows 
that the specimens belong in all probability to an undescribed species, 
but as no male worms were recovered it is considered inadvisable to 
publish a specific description until more material can be collected. 

The drawing is presented to show the peculiar filiform appendages 
projecting from either pole, a feature not only undescribed in any of 
the species of this genus, but, as far as the writer is aware, unique in 
the literature of nematodes.* The appendages consist of a cluster of 
seventeen to twenty-three filaments at either pole of the egg. Most of 
these are not over half the length of the egg, but one or two at either 
pole are over twice as long. 

One of the distinguishing characteristics of the trematode family, 
Notocotylidae, is the fact that the eggs are provided with a single long 
filament at either pole. To judge from the drawing of an egg of 
Notocotyle quinqueseriale Barker and Laughlin (1911), these filaments 
are simple prolongations of the chitinous shell. This is certainly the 
case in the genus Microcotyle, certain species of which have similar 
filaments, as MacCallum (1913) has seen these filaments in the process 
of formation from the shell. The filaments of Tropidocerca are, how- 
ever, apparently of a different nature, and are undoubtedly formed in 
a different manner. 

In examining a number of Tropidocerca eggs removed from a rup- 
tured uterus, it was observed that only those eggs which contained 
fully developed embryos and which were in a position to pass through 
the vagina, were equipped with these filaments. Less mature eggs had 
perfectly smooth shells, as with most nematodes. It is obvious, there- 


* Since this note was submitted for publication an article has appeared by 
Seurat (Compt. rend. Soc. de Biol. v. 76, 15 mai 1914) describing Tropidocerca 
nouvelli n. sp. which is characterized by similar appendages attached to the 
poles of the embryonated eggs. Seurat points out that similar appendages were 
observed by Kolliker on the eggs of Ascaris dentata, and by Lieberktthn in 
his Tropidocerca fissispina. Lieberktthn, failing to find this feature on all the 
eggs, considered it merely as an individual anomaly. 


46 THE JOURNAL (OF “PARASITOLOGY 


fore, that the filaments are not simple prolongations of the chitinous 
shell, but are added after the egg-shell is complete. This is also 
apparent from the figure in which the egg-shell is seen to form a com- 
plete ellipse, to the surface of which the filaments are attached. 

Leuckart (1867) has shown that the albuminous covering of the 
eggs of Ascaris lwmbricoides is deposited after the chitinous shell is 
complete, and the mamillations of this covering and the fact that it 
appears only on completely formed eggs suggest an analogy with these 
filiform appendages. 


Fig. 1—Egg of Tropidocerca sp., showing masses of filaments projecting 
from either pole. 


In one of the specimens of Tropidecerca sp. examined by the 
writer, which had been pressed under a cover-glass, a number of eggs 
attached at their poles by the entangling of their filaments, were seen 
to be forced through a rupture in the uterus. It would appear, there- 
fore, that these filaments are for the purpose of causing a number of 
eggs to cling together, thereby increasing the chances of infestation in 
the host. It is suggested by von Linstow (1879) that the eggs of the 


FOSTER—PECULIAR EGG OF TROPIDOCERCA 47 


genus Tropidocerca require an intermediate host. He bases his opinion 
on the relative thickness of the shell, the great number of eggs in a 
single female and their similarity to the eggs of the genus Filaria. 
If the life cycle is indirect, it would appear decidedly advantageous 
for the parasite that the intermediate host should be heavily parasitized, 
since in this way the handicap of an indirect life cycle would be 
lessened. 

The eggs of different groups of parasites are not infrequently 
provided with means for furthering their life cycle. These devices 
are either to enable the egg to remain on its host in the case of ecto- 
parasites, or to insure a heavy infestation of the host in the case of 
endoparasites. Among the former may be mentioned the long filament- 
ous hooklets which enable the egg of the genus Menopon to fasten in 
the feathers of the host, and the method of glueing the eggs of 
Haematopinus to the hairs of its host. As a method of insuring a 
heavy infestation of the host in endoparasites may be mentioned the 
egg sacs of the cestode genus Davainea and the strings of eggs ovi- 
posted by Strongyloides ovocinctus. In this case, as described by 
Ransom (1911), “the eggs passing out of the vulva lodge beneath an 
outer cuticular layer, which, when finally shed by the worm, is trans- 
formed into elongated egg-sacs, each containing from half a dozen to 
fifty or more eggs.” A still closer analogy to the filamentous append- 
ages shown is seen in the mamillated albuminous covering of Ascaris 
lumbricoides, which, as Blanchard (1888) has observed, sometimes 
causes the eggs to adhere to one another at the poles, exactly as was 
observed in the case of Tropidocerca. 


REFERENCES CITED 


Barker, D., and Laughlin, J. W. 1911. A new species of Trematode from 
the muskrat, Fiber zibethicus. Trans. Am. Micr. Soc., 30. 

Blanchard, R. 1888. Traité de zoologie médicale, v. 1. 

Leuckart, R. 1867. Die menschlichen Parasiten. v. 2, 1. Lief. 

von Linstow, O. 1879. Helminthologischen Studien. Arch. f. Naturg., 
45: 178. 

MacCallum, G. A. 1913. Further notes on the genus Microcotyle. Zool. 
Jahrb., Syst., 35. 

Ransom, B. H. 1911. The nematodes parasitic in the alimentary canal of 
cattle, sheep, and other ruminants. Bull. 127, Bureau Animal Industry. 


THE. ACTION ‘OF ARSENICAL DIPS) (IN  PREVER ie 
TICK, INFESTATION 


H. W. GRAYBILL 


Assistant Zoologist, Bureau of Animal Industry, U. S. Department of 
Agriculture. 


During the summer of 1912 the writer conducted experiments 
relating to the action of arsenical dips in preventing cattle from becom- 
ing infested with cattle ticks. The data obtained at that time were 
published in Bulletin 167 of the Bureau of Animal Industry. The 
results showed that cattle dipped in an arsenical dip are protected for 
two full days from becoming infested with seed ticks, but not for five 
days. During the past summer experiments were undertaken to deter- 
mine what protection, if any, such dipping offers for a period of three 
and of four days, and whether there is any mortality of ticks applied 
to and maturing on immune animals that have been subjected to a 
number of dippings at intervals of one and two weeks. 

The dip employed was the usual arsenical dip used in this country 
in the tick eradication work in the South, containing 8 pounds of white 
arsenic to 500 gallons of dip, with the exception that the pine tar was 
omitted in order to exclude the possibility of the tar playing any part 
in the results by exercising a repellent action on the ticks. 

Two experiments were carried out. In Experiment No. 1 cattle 
were exposed to infestation on the third and fourth days after dipping. 
Six calves non-immune to Texas fever were divided into three lots of | 
two each. In the case of Lot No. 1 seed ticks were applied three days 
after dipping, and in the case of Lot No. 2 four days after dipping. 
Lot No. 2 was not dipped and served as a control. Seed ticks were 
applied to this lot on the same date as to Lot No. 1. After the seed 
ticks were applied the different lots were placed in separate paddocks 
which they occupied until the close of the experiment. 

As a result of this experiment it was determined that animals 
dipped once in an arsenical dip containing sodium arsenite equivalent 
to 0.1863 per cent. AsO. were not protected from infestation when 
ticks were applied three days (Lot No. 1) and four days (Lot No. 2) 
after dipping. It was found, however, that the infestation of the 
dipped animals was light, whereas that of the two controls was heavy. 
It would therefore appear that dipping reduced markedly the degree 
of infestation. Since practically no dead nymphs were observed on 
the animals, it is evident that the lighter infestation of the dipped 
animals must have been brought about by an action on the larval stage, 


GRAYBILL—ARSENICAL DIPS 49 


which, as demonstrated in last year’s experiments (Bulletin 157, Bureau 
of Animal Industry), is in the nature of a destructive action. 

This experiment completes the work of last year, which demon- 
strated that cattle dipped in an arsenical dip such as used in this 
experiment are protected for two days, but not for five days, from 
infestation. The present experiment shows that the toxic action of the 
arsenic on and in the skin of dipped cattle is still effective to a certain 
degree on the third and the fourth day after dipping. 

In Experiment No. 2 ticks were applied to animals five days after 
the last of four dippings at intervals of two weeks and of one week. 
This experiment was conducted primarily for the purpose of determin- 
ing whether ticks that mature on animals that have been regularly 
dipped show any mortality after dropping off, due to arsenic absorbed 
from the skin of the animal. 

Six immune calves divided into three lots of two each were used. 
Lot No. 1 was dipped four times at intervals of two weeks, Lot No. 2 
four times at intervals of one week and Lot No. 3 remained undipped 
as a control. All the calves had ticks applied to them five days after 
the last dipping. 

In the case of Lot No. 1, one of the calves acquired a heavy, the 
other a light infestation; whereas, in Lot No. 2, in which the animals 
were dipped at intervals but half as long, the animals became only very 
lightly infested. In the control (Lot No. 3) both animals became 
heavily infested with ticks. It is therefore seen that dipping animals 
four times at intervals of one and of two weeks will not protect them 
from becoming infested when ticks are applied five days after the last 
dipping. The degree of infestation did not appear to be reduced in the 
case of the animals dipped at intervals of two weeks (Lot No. 1), but 
in the case of those dipped at intervals of one week the infestation was 
reduced to a very marked extent. It is therefore seen that when the 
interval between dippings is two weeks there is no increment in the 
toxicity of the skin of cattle, whereas when the interval is one week 
there is an accumulation of arsenic from previous dippings sufficient to 
destroy some ticks and thus reduce the degree of infestation. 

Large numbers of engorged ticks were collected from the dipped 
and the control animals and kept in the laboratory in Petri dishes. 
‘Observations were made on these with regard to mortality, oviposition, 
number of eggs deposited and the percentage of eggs hatching. It was 
found by comparison with the controls that the ticks from the dipped 
animals manifested no abnormality. In other words, it may be said 
that ticks placed on animals five days after the last of four dippings, 
at intervals of one week and of two weeks, and permitted to engorge 
show no indication of arsenical poisoning. 


EORHYNCHUS: A PROPOSED NEW NAME FOR NEO- 
RHYNCHUS HAMANN PREOCCUPIED * 


H. J. Van CLEAVE 


The genus Neorhynchus was founded in 1892 by Hamann to include 
Echinorhynchus rutili Miller and Echinorhynchus agilis Rudolph. 
Practically all investigators dealing with the Acanthocephala since that 
date have accepted this generic name. Recently attention has been 
called to the fact that the name Neorhynchus is preoccupied. Sclater, 
in 1869, and, again, Milne Edwards, in 1879, employed it for other 
groups. In accordance with the laws of nomenclature, it then becomes 
necessary to reject the name Neorhynchus as applied to Hamann’s 
genus.» I propose the name Eorhynchus to designate these forms. 
While all other investigators dealing with this genus have been limited 
to a study of the two original species, it has been my good fortune to 
include five additional species in a comparative study, the results of 
which have led me to a restatement of its essential characteristics. 
As pointed out in an earlier paper (1913), I consider the following 
points as diagnostic for this genus of Acanthocephala: 

1. Six giant nuclei in the subcuticula arranged, normally, ane in 
the middorsal line of the body and one in the midventral line. 

2. Two giant nuclei in one lemniscus and only one in the other. 

3. Proboscis receptacle with but a single muscle layer in its wall. 

In the light of this analysis, the contentions of de Marval (1904: 
582) and of Monticelli (1905: 217), that Apororhynchus hemignathi 
Shipley should be included in this genus are based on an inadequate 
understanding of its natural limits. 

Shipley, in his description of A. hemignathi (1896: 210), wrote: 
“As in Neorhynchus, the number of nuclei is very small, some twelve 
to twenty seem to suffice for the whole subcuticle, and perhaps two to 
four for each lemniscus. The nuclei are scattered about in a most 
irregular fashion. 

I have shown (1913) that not alone the presence of giant nuclei, but 
more strikingly their number and arrangement furnish a sure criterion 
for the determination of members of this genus. Shipley’s genus 
Apororhynchus, because of its radical departure from the typical struc- 
ture of the Eorhynchi, cannot be included within the genus Eorhyn- 
chus. The valid species of this genus are, then, Eo. rutili (Muller 


* Contributions from the Zoological Laboratory of the University of Illinois, 
under the direction of Henry B. Ward, No. 32. 


VAN CLEAVE—EORHYNCHUS 51 


_ 1784), Eo. agilis (Rudolphi 1819), Eo. emydis (Leidy 1852), Eo. 
gracilisentis (Van Cleave 1913), Eo. longirostris (Van Cleave 1913), 
Eo. cylindratus (Van Cleave 1913) and Eo. tenellus (Van Cleave 
1913). 

Hamann (1892) also created the family Neorhynchidae for the 
single genus Neorhynchus. Porta (1907:409) accepted Hamann’s 
revision of the Acanthocephala only in part, recognizing but two 
families, Echinorhynchidae and Gigantorhynchidae, and included Neo- 
rhynchus under the former. The characteristics already listed as diag- 
nostic for the genus Eorhynchus, together with the complete fusion of 
the cement glands, are such essential features that the inclusion of 
Eorhynchus in the same family with Echinorhynchus would so distort 
our conception of the family Echinorhynchidae that it would cease to 
be a natural division of the Acanthocephala, and would become a 
purely artificial assemblage. In view of these facts I consider that the 
evidence fully justifies the retention of the family rank originally 
attributed to these forms for which the family name now becomes 
FEorhynchidae. 

The writer’s extensive studies on the cytology of the Eorhynchidae 
furnish conclusive evidence in support of the foregoing arguments. 
These studies in detail appear in the June number of the Journal of 
Morphology. 

REFERENCES 


Hamann, O. 1892. Das System der Acanthocephalen. Zool. Anz., 15: 195. 

de Marval, L. 1904. Sur les acanthocéphales d’oiseaux. Note préliminaire, 
Rey. suisse de zool., 12: 573-583. 

Monticelli, F. S. 1905. Per una rettifica. A proposito di una proposta 
classificazione degli Acantocefali. Boll. Soc. Natural. Napoli, 19: 217-218. 

Porta, A. 1907. Contributo allo studio degli Acantocefali dei Pesci. Bio- 
logica Torino, 1 :377-423. 

Shipley, A. E. 1896. On Arhynchus hemignathi, a new genus of Acantho- 
cephala. Quart. Jour. Micr. Sci., 39: 207-218. 

Van Cleave, H. J. 1913. The Genus Neorhynchus in North America. Fool. 
Anz., 43: 177-190. 


SOCIETY PROCEEDINGS 


THE HELMINTHOLOGICAL SOCIETY OF WASHINGTON 


The sixteenth regular meeting of the society was held at the residence of 
Dr. Ransom, Dec. 18, 1913, Dr. Ransom acting as host and Dr. Graybill as 
chairman. 

A letter from Mrs. Elise Huber, announcing the death of her husband, Dr. 
J. Ch. Huber, a foreign corresponding member of the society, was read and the 
secretary instructed to reply, conveying the society’s regrets. 

The following papers were read: Notes on Sarcosporidia, by Mr. Crawley; 
The Ingestion by Man of Cysticerci of Carnivore Tapeworms, by Mr. Hall; 
Variations in the Eggs of Ascaris, by Mr. Foster; The Effect of Refrigeration 
on Trichina, by Dr. Ransom; and The Effect of Arsenical Dips on Ticks, by 
Dr. Graybill. 

Maurice C. HAL, Secretary. 


The seventeenth regular meeting of the society was held at the residence 
of Mr. Hall) Jan. 22, 1914, Mr. Hall acting as host and Dr. Ransom as chairman. 

Mr. Crawley gave a review of Calkins’ paper on the cultivation of amoebae. 

Mr. Foster exhibited some drawings of the eggs of Tropisurus and pre- 
sented a note in regard to them. 

Dr. Hassall called attention to the index of Castellani and Chalmers latest 
edition of Tropical Medicine, noting the fact that it had been very poorly con- 
structed and introduced a number of synonyms. 

Dr. Cobb presented a note on the crystalline inclusions in the intestinal cells 
of Rhabditis and other free-living nematodes, and demonstrated these inclusions. 

Mr. Hall presented a note proposing a new genus for Distoma tricolor Stiles 
and Hassall 1894. 

Dr. Ransom presented a paper on the refrigeration of beef infested with 
beef measles. 

Maurice C. Hatt, Secretary. 


The eighteenth regular meeting of the society was held at the residence of 
Mr. Crawley, March 12, 1914, Mr. Crawley acting as host and Dr. Graybill as 
chairman. 

Mr. Hall presented a paper entitled An Unusual Case of Fatal Poisoning 
from the Administration of Male Fern as a Vermifuge. 

Mr. Crawley presented a paper entitled Early Stages in the Life History 
of Sarcocystis muris. 

Maurice C. Hatt, Secretary. 


The nineteenth regular meeting of the society was held at the residence of 
Mr. Foster, April 14, 1914, Mr. Foster acting as host and Dr. Cobb as chairman. 
Dr. Georgina Sweet and Miss Frieda Cobb were the guests of the society. 

Dr. Ransom presented a paper entitled The Occurrence of a Fly Larva in 
the Heart of a Hog. 

Mr. Hall presented a paper entitled A New Genus of Discodrilids, with a 
Key to the North American Species. 

Mr. Foster presented a paper entitled The Specific Characteristics of 
Metastrongylus apri and M. brevivaginatus. 


HELMINTHOLOGICAL SOCIETY OF WASHINGTON 53 


Dr. Cobb exhibited and discussed his recent publication entitled Antarctic 
Marine Free-Living Nematodes of the Shackleton Expedition; Contributions to 
a science of nematology. This paper is published by the author as a tribute 
to Shackleton. The excellent illustrations are by Miss Frieda Cobb, a limited 
number of copies being hand colored, and the very striking cover-design is 
by Mr. Chambers. The publication bears the stamp of that individuality which 
is so characteristic of Dr. Cobb’s papers. 

Maurice C. HAtt, Secretary. 


The twentieth regular meeting of the society was held at the residence of 
Dr. Cobb, May 12, 1914, Dr. Cobb acting as host and Dr. Ransom as chairman, 

Mr. Hall presented a paper entitled The Superfamilies of the Parasitic 
Nematodes. 

Mr. Foster presented a triradiate specimen of Taenia pisiformis and some 
cross sections of the worm, which was collected from a dog imported from 
Europe and held in quarantine at Athenia, N. J. The specimen is therefore 
European and not American. 

Dr. Ransom presented a note on the relation of parasitic worms, especially 
nematodes, to cancer, and called attention to his description of Agamone- 
matodum gaylordi, recently published in a Fisheries Bulletin entitled Carci- 
noma of the Thyroid in the Salmonoid Fishes, by Gaylord and Marsh. There 
seems to be very good evidence that the nematode may act at times as an 
inoculating agent in the production of carcinoma. 

Dr. Cobb exhibited to the society specimens representing twenty-seven new 
genera of free-living nematodes and pointed out various peculiarities in con- 
nection with the annulation, mouth parts, spicules, spermatozoa and nutritional 
granules. Maurice C. Hatt, Secretary. 


NOTES 


HELMINTHOLOGIC INVESTIGATIONS 


The departure of the expedition, under the direction of Dr. R. T. Leiper, 
Helminthologist of the London School of Tropical Medicine, to the Eastern 
Tropics, is an event which must prove of considerable scientific importance. 
Accompanying Dr. Leiper is a medical officer seconded by the admiralty, 
Surgeon E. L. Atkinson, R.N., who, since his return from the Scott Antarctic 
Expedition, has been working at the London School of Tropical Medicine on 
pathologic specimens he brought back from South Polar regions. The per- 
sonnel of the expedition is further perfected by the presence of a zoologist, 
Mr. A. Cherry-Garrard, who served as assistant zoologist in the late Antarctic 
Expedition. The funds necessary for the investigation have been found partly 
from the bequest of the late Lord Wandsworth to, and now under the control 
of, the London School of Tropical Medicine, and partly they have been con- 
tributed to by the Tropical Disease Research Fund of the Colonial Office. 

The primary object of the expedition is to ascertain the mode of spread of 
the trematode diseases of man. 

Facilities for investigation have been afforded by several countries, and in 
Sumatra the United States Rubber Company have specially invited the expe- 
ditionary party to study the helminths as they affect the workmen on their 
rubber estates. 

In a previous leader in this journal we drew attention to the solidarity 
of scientific investigation, citing as an instance the bearing Arctic and Antarctic 
pathologic and zoologic findings had on our geographical knowledge of the 
spread of disease, and of the limitations or otherwise of pathologic germs by 
heat and cold. The association of experts with a first-hand knowledge of these 
subjects in the frigid zones is of particular interest on the occasion of this the 
most recent scientific expedition to the Tropics. 

The intestinal parasites met with in man in the Tropics might well be termed 
legion, and no medical practitioner who deals with tropical ailments at home 
or abroad can afford to do aught as a first and stereotype item of practice but 
to administer an anthelmintic, or at least a simple purge, so as to ensure that 
there is no worm or its ova complicating the symptoms of any of the intestinal 
derangements that may come to him for treatment. How often even the most 
skilful doctor in the Tropics has had cause to repent the non-observance of 
this practical axiom. Intestinal fluxes ascribed to dysentery, acute, chronic or 
intermittent sometimes prove intractable to the customary remedies for dysen- 
teric lesions, and the cause of the resistance to their action is not detected 
until the patient goes to another doctor, who, administering an anthelmintic, 
clears up the mystery, to the chagrin of the aforesaid and the loosening of the 
unflattering tongue of the sufferer. Apart, however, from the mere clinica! 
aspect of the good this expedition may do, there are larger and more impor- 
tant factors to be considered, namely, the public health and the commercial 
points of view. These are intimately associated. The good health of the 
workers in a mine, on a rubber, tea or coffee plantation, or on any commercial 
undertaking where men are employed in large numbers, affects the commercial 
value of the undertaking they are engaged on to the extent that it may have 
to be abandoned by the capitalist owing to the monetary losses ill-health entails. 
Such a state of things affects the whole world by the fact that many necessary 
articles of food become dearer not only locally, but universally, and the tea, 
coffee, cocoa, sugar, rice, tapioca, sago, etc., of our ordinary diet is enhanced 
in price. Thirdly, the scientific advance likely to ensue from the expedition 
may be hoped to be great and lasting. The men engaged on it have a high 
scientific reputation and their work is sure to be sound and reliable. It is 
to be hoped that our knowledge of bilharziosis will be advanced, that anky- 
lostomiasis will be rendered more capable of being controlled, and that the 
flora of the intestine generally will be placed on a surer footing than obtains 
at present.—Journal of Tropical Medicine and Hygiene, March 16, 1914. 


Pies Journal of Parasitology 


Volume 1 DECEMBER, 1914 Number 2 


GK SPAR ALY SIS * 


Joun L. Topp 


(Communicated to the Royal Society of Canada, May 28, 1914.) 


Although for many years it has been well known by physicians 
practicing in southern British Columbia that paralysis may appear in 
children who have been bitten by ticks, it is only a few months since 
accounts of such an affection as “tick paralysis” appeared in scientific 
publications (Todd, 1912, 1912a; Temple, 1912). Medicine owes a 
debt to these practitioners, Corsan, Henderson, Hall, Kingston, Morris, 
Rose, Shewan and Temple. Their observations have supplied the first 
records of paralysis produced in children by the bites of ticks. 

The first accounts of the disease were merely short descriptions 
of the symptoms which had been observed by half a score of physicians 
in a series of more than twenty-five cases. The patients had been seen 
during a number of years—~ Temple saw his first case in 1898 — in 
various places in southern British Columbia and in the neighboring 
portions of the United States. All of the patients were children ; there 
were, however, somewhat obscure accounts of instances in which symp- 
toms, resembling those observed in children, had been seen in men who 
had been bitten by ticks. The history and symptoms were much alike 
in all of the cases. The usual story was that an active and apparently 
healthy child suddenly developed a paresis or paralysis of the legs; 
neither abnormal temperature nor any other symptom but paralysis 
was constant. After the tick was discovered and removed the symp- 
toms disappeared within a few hours, with the possible exception of a 
more or less local reaction, often probably due to a secondary bacterial 
infection, at the site of the tick’s bite. In some of the cases reported 
the tick was not removed ; in them the paralysis progressively involved 
the whole body until reflexes and control of the sphincters were lost, 
and death ensued. 

The symptoms of these cases suggest infantile paralysis (acute 
poliomyelitis) ; but they are probably to be distinguished from cases 


*I wish to express my indebtedness to all those who have supplied me with the information 


and material which has made this paper possible; the names of most of them are mentioned 
in it. 


Fal 


Va! 


56 THE JOURNAL. OF PARASITOLOGY 


of that disease by the invariably transitory nature of their paralyses. 
In no instance has “tick paralysis” Jeft permanent disability. It seems 
impossible to explain these many cases of “tick paralysis” as mere 
coincidences, in which tick infection has been fortuitously associated 
with sporadic attacks of a peculiarly mild form of acute poliomyelitis ; 
none of the practitioners who saw these cases have recorded the con- 
temporary existence of definite cases of acute poliomyelitis. Also, the 
symptoms of these cases of paralysis have little in common with the 
symptoms of the typhus-like “spotted fever,’ which is seen in persons 
bitten by ticks (Dermacentor venustus) 1n some parts of Montana. 
For these reasons it seems certain that a form of paralysis associated 
with the bites of ticks occurs in children in western North America 
and that the infection can be identified with no known disease. Similar 
cases from Wyoming and Montana have been reported (Bishopp and 
King, 1913). More recently very similar histories of instances in 
which paralysis has followed the bites of ticks (probably Lvodes ricinus 
or /. holocyclus) have been reported from Australia (Eaton, 1913). 

Hadwen (1913) describes the occurrence of paralysis in sheep, 
which have been bitten by ticks, in British Columbia. He and Nuttall 
(1914) give references to publications which describe the existence of 
a paralysis caused by ticks (of a species, /. pilosus, other than that 
which exists in British Columbia) in South African sheep. Hadwen 
succeeded in producing paralysis in a lamb on which a tick (D. venus- 
tus) had, experimentally, been allowed to feed. He, with Nuttall 
(Hadwen and Nuttall, 1913), was successful in producing the same 
symptoms in a dog. A very complete bibliography of the effects of 
tick bite can be reached by a search through the papers referred to in 
this communication. Hadwen, especially, gives a good list of articles 
on the bites of ticks. 

Since the observations contained in the publications mentioned 
above were published, the cases recorded below have been reported. 

Dr. W. J. Knox, Kelowna, B. C., records two cases. 


April 23, 1913, a boy of 4 years had pronounced flaccid paralysis from the 
hips down. He could not stand; his arms were weak; there was hyperesthesia ; 
the pupils were normal; the temperature was 100 F.; the pulse was 112. The 
first symptom had been a little stiffness of the legs twenty-four hours previ- 
ously; it progressed until in twelve hours walking was extremely difficult. 
A tick was found in the left axilla. It was removed by snipping it out with 
the tissue about its head; the wound was dressed antiseptically. A purgative 
was given to the child and, under slight stimulation, the pulse quickly 
became full and steady. In twenty-four hours the child could move his limbs 
fairly well, and in forty-eight hours he was apparently as well as ever. 

April 21, 1914, a girl of 3 years had slight paralysis of the right leg. The 
temperature was normal. Her condition was said to be better than it had 
been two hours previously; so rest and a purgative were prescribed. Twelve 
hours later the child was stuporous. Her legs and arms were entirely par- 


TODD TICK ~ PARALYSIS 57 


alyzed; she could neither articulate nor swallow, and seemed to be sinking 
very rapidly. The pulse was 130, small and weak. The temperature was 
102 F. No tick was found on the child’s body, but the hair was clipped short 
and a small wood tick was found at the base of the skull. It was removed 
by snipping it out with the tissue surrounding its head. The wound was 
dressed antiseptically and purgatives and stimulants were given; in six hours 
the child’s temperature was 99.4 F., her pulse 100 and regular and she was 
conscious and asking for water. In twelve hours she could move her limbs 
and in five days was running about as well as ever. 


Dr. Knox also reports a case of quite another type in an adult. 


April 27, 1914, a man of 28 years was seen. He gave a history of having 
pulled off the body of a tick, leaving the head behind, from the calf of his 
left leg. At the site of the bite was a large bluish-black area surrounded by 
much induration. The patient’s body was covered with a spotted erythema. 
He felt very ill, and complained of vertigo and of pains in the back and in 
the legs. His pulse was 108, his temperature 102.5 F. Sensation was lost in 
the right leg from 6 inches below the hip-joint; the left leg was paralyzed. 
The head of the tick was excised and the wound dressed antiseptically. A 
purgative was given and in twelve hours the temperature had dropped to 99.6 F. 
and the pulse to 86. In thirty hours the temperature was normal, and the 
rash and pain were gone; in four days the patient, being well, was discharged. 

Dr. Knox records an instance in which a very thin colt, so weak that it 
could not stand, was covered with ticks; the ticks were removed and within 
a few days the colt was able to walk and gradually regained its health. (It 
is possible that this was nothing more than a case of severe “tick worry.” ) 


Dr. Elmer Fessler, St. Regis, Montana, records two cases. 


On the morning of May 19, 1914, a 2-year-old girl was found to be unable 
to walk or stand, although she had slept well and had been quite well on 
the previous day. She tried to walk several times during the day but she was 
unable to do so. When the physician first saw her, on the morning of the 
twentieth, her temperature was 96.5 F., her pulse 120 and her respiration was 
normal. She could move her legs, but she could not stand, and the leg 
reflexes were gone. There was considerable loss of function of the arms. 
The mother said more than on the previous day. No urine had been passed 
for twenty-four hours. Although the child was somewhat peevish, she took 
her food as usual. Two ticks (Dermacentor venustus) were removed frem the 
nape of the neck; one was a half-engorged female, the other a male. The 
child was given cathartics. In six hours her hands were moved less clumsily 
and a little later she tried, unsuccessfully, to stand. At 9 the next morning 
she could walk and by noon was running about as usual. She has been 
quite well ever since. 

In 1905 a girl of 5 years was seen who was said to have been unable to 
walk for forty-eight hours. She could not move her legs which were without 
reflexes. She could move her arms clumsily, but could hold nothing in her 
hands. A large tick was removed from the base of the skull and on the 
following day she seemed to be quite well, save for a slight weakness that 
persisted for some days. 


Dr. A. W. Kenning, who practiced in Rossland, southern British 
Columbia, for sixteen years, mentions two cases. 


One, the only fatal case, which he saw, was in a girl of 8 She had 
general paralysis and when the tick was found on her arm, she was comatose 
with a rapid pulse and high temperature. The other case was a child of 6 
who had general paralysis; the whole body was involved. On removing the 
tick from the child’s head, she recovered as was usual in such cases. 


58 THE JOURNAL OR PARASITOLOGY 


Dr. G. S. Gordon, Vancouver, B. C., has records of one case. 


In 1904 (?) a girl of 5 years was seen. The child came of neurotic stock; 
she seemed well in every particular save that, though she could move her 
arms and legs while sitting on the floor, she could not walk nor put one 
leg before the other when she was supported in the erect position. A second 
practitioner, whose opinion was asked, told the parents to look for “wood 
ticks.” One was found and on its removal the symptoms disappeared. 


Dr. R. W. Irving, Kamloops, B. C., records a case in a child 


May 1, 1912, a boy of 8 years was seen. He complained of numbness in 
his legs and was unable to stand. He seemed rather sleepy and dull; but 
otherwise was healthy, save that he could only move his legs in an ataxic 
manner while lying in bed and that at times his arms seemed to become weak. 
The special senses were not affected nor were the cranial nerves involved. 
The knee-jerks were not obtainable. There was no ankle clonus, nor Babinski’s 
sign. The sphincters were under control and there were no areas of anesthesia 
or hyperesthesia. The pulse was normal and the temperature was 99.2 F. 
A tick was found at the base of the skull and it was removed. Under rest 
and catharsis the boy, in three or four days, became perfectly well. 


Dr. Irving, with Dr. Murphy, saw a case in which definite nervous 
symptoms in an adult were associated with the presence of a tick. 


A normal, well-nourished male of 40 years complained that four days 
previously he found it difficult to speak and that he was awkward in his move- 
ments. He had been perfectly well and said that he had felt as though he were 
“partially drunk.” A day later he fell on attempting to arise in the morning 
and was unable to balance himself in any way. When the patient was seen 
there were few constitutional symptoms and his only other complaint was 
that he felt “a bit seedy.’ On examination his hands and arms were found 
to be weak and incoordination was definitely present. The knee-jerks were 
absent; there was no ankle clonus, Babinski’s sign, area of anesthesia or 
hyperesthesia, and no involvement of cranial nerves nor loss of sphincter con- 
trol. A tick was found on the upper part of the back and removed. The 
symptoms commenced to disappear within twenty hours. In three days the 
man was as well as ever, and in three days more he was married. 

These and other cases add a little to the first descriptions of the 
affection; they show that an elevated temperature, a rapid pulse and 
respiration and other constitutional conditions may frequently be 
symptoms. It also seems probable that nervous symptoms may super- 
vene in adults who have been bitten by ticks. Convulsions, sudden 
stupidity and clumsiness are mentioned as symptoms that may follow 
tick bite. One physician asserts that in southern British Columbia 
practitioners, who have been in the country for long, always look for 
ticks on a child who has a convulsion. One or two physicians mention 
cases which suggest that spotted fever may not be entirely confined to 
Montana. There are many records of ulcers and other inflammatory 
lesions at the site of ticks’ bites. Sometimes these lesions are said to 
be suggestively obstinate to ordinary treatment. 

The experiments recorded below were made in the hope of pro- 
ducing, under experimental conditions, paralysis in laboratory animals. 
by the bites of ticks. 


TODD—TICK PARALYSIS 59 


The way in which the experiments were done was practically iden- 
tical in each instance. The animals, together with control animals, 
were well cared for. The lambs, when the experiments commenced, 
were from 4 to 6 weeks old; they were kept in pens with their mothers. 
The puppies were about the same age; they were kept in individual 
cages and fed on milk. The ticks were attached either to the nape of 
the neck or to the loins as is stated. The hair was removed either by 
slipping and shaving or by epilating powder. ‘The ticks were then 
placed on the skin beneath a finely perforated porcelain filter cone, 
which measured about 1 inch in diameter at the base and 1 inch in 
height. The cone was fastened to the animal by an ample bandage of 
adhesive plaster, firmly stitched in position. As a rule, this method of 
attaching the ticks was satisfactory. In only one or two instances did 
the ticks find their way beneath the edge of the cone and become lost 
or fixed to the plaster. Paralysis was produced in no experiment. 


Monkey 1.—Aug. 16, 1912. Two ticks (D. venustus or D. andersoni), sent 
by Dr. J. B. McClintic, Victor, Mont., were placed on the nape of the neck 
of a large rhesus monkey; August 21, both ticks, each half engorged and firmly 
attached, were removed. August 24, three ticks, from the same source, were 
placed on the nape of the neck; August 31, two engorged ticks were removed; 
one tick had disappeared. November 18, four ticks, obtained by Dr. Lee Ganson 
of Odessa, Wash., from “jack rabbits,” were placed on the nape of the neck 
of this monkey; November 30, during the night the monkey pulled off the 
bandage and destroyed the ticks. 


Monkey 2.—Aug. 16, 1912, three ticks (D. venustus or D. andersoni), sent 
by Dr. J. B. McClintic, Victor, Mont., were placed on the nape of the neck 
of a small rhesus monkey; August 20, the half-engorged ticks were removed. 
August 24, two ticks, from the same source, were placed on the neck; August 
30, one engorged tick was removed; the second was dead. 


Monkey 3.—May 2, 1913, three ticks (not identified) were placed on the 
nape of the neck of a large rhesus monkey. One of these ticks was that 
which was removed from the little boy whose case is recorded above by 
Dr. Knox at Kelowna, B. C. The other two were sent by Dr. Boyce, from 
a horse, from the same place. May 26, the engorged ticks were removed. 


Ten ticks, all of them very probably D. venustus, fed on one or the 
other of these three monkeys. Paralysis appeared in none of the three, 
although the child from which one of the ticks had been taken was 
paralyzed. 


Lams 1.—April 20, 1914, two ticks (D. venustus) from H. P. Wood, Esq., 
Florence, Mont., were placed on the neck of a lamb about 3 weeks old. The 
ticks were collected from cattle in a district where “spotted fever” exists. 
April 21, the lamb was obviously disinclined to move. April 22, the lamb died. 
A naked-eye examination at the autopsy revealed nothing beyond four or 
five superficial, almost petechial, pneumonic areas on the lungs. One of these 
was sectioned and the lung was found to be congested and collapsed, rather 


than pneumonic. The stomach and intestines were filled with normally digested 
food. 


LAMB 2—On April 20, 1914, three female ticks, two D. venustus and one 
D albipictus, collected by Seymour Hawden, D.V.Sci., from horses at Keremeos, 


60 THE JOURNAL “OF® PARASITOLOGY 


B. C., were placed on the neck of a lamb about 4 weeks old. April 30, the 
three ticks, none of them engorged, were removed. Four ticks, three male 
and one female D. venustus, sent by H. P. Wood, Esq. (see Lamb 1), were 
placed on the neck; May 9, the engorged female and three unfed male ticks 
were removed. May 28, an engorged female D. venustus, taken by Dr. Arthur 
from the skin of a bear, at Nelson, B. C., was placed on the neck; June 5, 
the tick was removed unfed. June 19 two ticks, D. venustus, sent by R. A. 
Cooley, Esq., Bozeman, Mont., were placed on the neck; June 24, both ticks 
were removed, unfed. : 


Lames 3.—April 24, 1914, four ticks, from H. P. Wood, Esq., Florence, Mont., 
were placed on the neck; April 30, two of the ticks were lost and one dead, 
the remaining living tick was not engorged. Four other ticks, two male and 
two female D. venustus, from the same source, were placed on the lamb; 

May 9, one of the ticks was dead, the three living ones were removed, none 
‘ were engorged. May 28, one female, D. venustus, partially engorged, from 
Dr. Arthur (see above) was placed on the neck; June 5, the tick was dead; 
and probably was never attached. June 19, two D. venustus, from Bozeman, 
Mont., were placed on the neck; June 24, one unfed tick was removed, one 
was missing. June 25, three D. venustus, two females and one male, from 
Bozeman, Mont., were placed on the neck; July 2, one engorged female and 
one attached male tick was removed. 


Lamp 4.—April 24, 1914, one male and one female D. venustus, from Flor- 
ence, Mont., were placed on the neck; April 30, ticks removed; both had 
attached; one was fully engorged. Four other ticks, one male and three 
females, from the above source, were placed on the loins; May 9, ticks 
removed; all had attached; three were engorged. May 28, three partially fed 
ticks, one male and two female D. venustus, from Dr. Arthur (see above) were 
placed on the neck; June 5, ticks removed; the two female ticks were engorged; 
the male was not. June 6, a half-engorged female D. venustus was placed 
on the neck. This tick was one of those removed from the case recorded above 
by Dr. Fessler. June 12, tick removed; probably had not attached. June 19, 
a male D. venustus, also from Dr. Fessler’s case, previously fed on Puppy 1, 
was placed on the neck; June 24, tick dead. June 25, a male and a female 
D. venustus from Bozeman, Mont., were placed on neck; July 2, the engorged 
female and unfed male ticks were removed. 


Lams 5.—April 30, 1914, a tick (unidentified) from the case described above 
by Dr. Irving, was placed on the neck; May 9, tick dead; apparently had not 
attached. May 28, one male and two female D. venustus from Dr. Arthur (see 
above) were placed on the neck; June 5, ticks removed; two were engorged; 
one not. June 19, two ticks, D. venustus, from Bozeman, Mont., were placed 
on the neck; June 24, ticks removed, only one was half engorged. June 25, 
four ticks, two male and two female D. venustus, from Bozeman, Mont., were 
placed on the neck; July 2, one female was dead, the remainder being 
attached, were left in position; July 7, an engorged female and one dead and 
one still attached male were removed. 

Lams 6.—May 5, 1914, two female D. venustus, from Dr. Hawden (see 
above), were placed on the neck of this lamb; May 16, both ticks, attached 
but not engorged, were dead. May 28, one partially engorged female 
D. venustus from Dr. Arthur (see above), was placed on the neck; June 5, 
tick dead, probably had not attached. June 19, one male and “one female 
D. venustus, from Bozeman, Mont., were placed on the neck; June 24, both 
ticks dead; one attached; neither engorged. June 25, one female and one male 
D. venustus, from Bozeman, Mont., were placed on the neck; July 2, male dead, 
female engorged. 

Lames 7.—May 9, 1914, a female D. venustus, obtained from surveyors by 
Dr. Arthur of Nelson, B. C., was placed on the neck of this lamb. May 16, 
tick removed, three-fourths engorged. May 28, two partially engorged female 
D. venustus, obtained from Dr. Arthur, at Nelson, B. C., from a bear skin, were 


TODD—TICK PARALYSIS 61 


placed on the neck; June 5, both ticks dead, probably never attached. June 19, 
two ticks, D. venustus, from Bozeman, Mont., placed on the neck; June 24, 
ticks removed, both attached, one half engorged. June 25, two ticks, 
D. venustus, from Bozeman, Mont., were placed on the neck; July 2, one male 
tick and one attached female removed, both were unfed. 


About twenty ticks, almost all of them adult male or female D. 
venustus, fed on one or the other of seven lambs. Six of the lambs 
remained in perfect health. One of them (Lamb 1) died on the second 
day after two ticks were placed on it; it is not probable that the ticks 
were the cause of death, since other ticks from the same source were 
harmless to similar animals. 


GurtneEA-Pic 1—May 6, 1914, a male and a female D. venustus sent by H. P. 
Wood, Esq., Florence, Mont., were placed on the loins; May 16, ticks removed, 
the female was partially engorged. June 3, dead; the guinea-pig had seemed 
to be quite well, and temperature was not abnormal until May 16, when daily 
observations were discontinued. At autopsy, there were no signs of irritation 
about tick bites; the cause of death was bronchopneumonia. 


No sign of paralysis followed the feeding of a single tick on a 
guinea-pig. 

Pupry 1—June 6, 1914, a male D. venustus, sent by R. A. Cooley, Esq., 
Bozeman, Mont., was placed on the back of a puppy, about 6 weeks old. This 
tick was one of those taken by Dr. Fessler from the case recorded above by 
him; June 12, tick removed, unattached and unfed. June 19, two male 
D. venustus, from Bozeman, Mont., were placed on the back; June 24, two 
ticks removed, both unfed and dead. June 25, one male and one female 


D. venustus, from Bozeman, Mont., were placed on the loins; July 2, both 
ticks dead, neither fed. 


Puppy 2—June 19, 1914, two male D. venustus, from Bozeman, Mont., were 
placed on the loins of a puppy about 8 weeks old; June 24, both ticks removed, 
unfed and dead. 


Puppy 3.—June 19, 1914, two female D. venustus, from Bozeman, Mont., were 
placed on the loins of a puppy about 8 weeks old; June 24, ticks removed, both 
engorged. 

Paralysis did not appear in a puppy on which two ticks fed. 

The ticks used in all of these experiments were identified with the 
assistance of the key published by Banks (1908). Dermacentor ven- 
ustus and D. albipictus were the only ticks received from southern 
British Columbia, and of these the former was much the more com- 
mon. In a personal letter, Hadwen wrote that it is difficult to get 
D. venustus to feed under laboratory conditions unless it has been 
recently collected ; the diaries of the above experiments ratify his state- 
ment. The ticks used in these experiments were confined in Ehrlen- 
meyer flasks plugged with cotton wool, and were kept in a humid 
atmosphere at 25 C. Care was taken to give every tick every chance 
for feeding; several of the ticks used in these experiments had oppor- 
tunities for feeding on two or more animals. These conditions seemed 
to agree with some females which laid many fertile eggs; but about 
half of the females laid only a few eggs and these infertile ones. 


62 THE JOURNAL OF PARASITOLOGY 


In the records of the tick-feeding experiments only those ticks 
which were definitely engorged are counted as having fed. It is 
unfortunate that their number is not larger and, especially, that the 
ticks which had been removed from paralyzed clildren would not all 
feed well on the experimental animals. Enough fed, however, to 
justify the statement that, under the conditions of these experiments, 
not every bite of a tick (D. venustus and D. albipictus) is able to cause 
paralysis in the laboratory animals employed. 

It was thought that the paralysis produced by the bites of ticks in 
children might be caused by some toxin secreted by the ticks. Experi- 
ments were therefore designed to ascertain whether an extract capable 
of producing paralysis in laboratory animals could be obtained from 
the bodies of ticks. 


EXPERIMENT 380—About 4 c.cm. of larvae of “Texas fever ticks,” 
(Margaropus sp.?), obtained from Washington, D. C., through the courtesy of 
the Bureau of Animal Industry, were dried for six weeks, and were then 
ground up in 50 c.cm. of a 4 per cent. solution of glycerin in distilled water. 
The resulting mixture was shaken for one and a half hours and then passed 
through a Buchner and a Berkefeld filter. The fluid so obtained was inoculated 
beneath the skin of the rump of two rats and two mice; one rat and one mouse 
received 2 c.cm., the other rat and mouse 1 c.cm. The two mice died within 
twenty-four hours; no cause of death was evident. The rat which received 
1 c.cm. died ninety-six hours after inoculation; the cause of death was not 
evident. The second rat died two weeks after inoculation, from bronchopneu- 
monia; neither it nor any of the animals had ever shown any sign of paralysis, 
or of suppuration at the site of inoculation. 


EXPERIMENT 400.—Ten adult Margaropus annulatus and about 700 larvae, 
also obtained from Washington, D. C., were dried, ground up in glycerin and 
water, shaken and filtered in the same way as was done in Experiment 380. 
Four c.cm. of the filtrate was inoculated beneath the skin at the back of the 
neck, of two rats; one received 2 c.cm., the other 4 c.cm. Neither rat developed 
any sign of paralysis nor was there suppuration at the site of inoculation in 
either. 

EXPERIMENT 531.—About 3.5 ccm. of dried ticks of all ages and of both 
sexes were employed. Most of them were adults. With the exception of one 
or two D. albipictus, all were D. venustus. These ticks were those, or their 
progeny, which had been used in the feeding experiments described above. 
All were ground up in 50 c.cm. of a 4 per cent. solution of glycerin in dis- 
ti‘led water, shaken for two and a half hours and then filtered through a 
Buchner and a Berkefeld filter. Respectively, 2 c.cm., 4 c.cm: and 5 c.cm. of 
the clear filtrate was inoculated under the skin of the rumps of three young 
white rats, weighing about 30 gm. each. Paralysis appeared in none of them, 
although as in the previous experiments, all showed some disinclination to 
move; probably because of the soreness at the site of inoculation. One rat 
died four days after the inoculation. There was no sign of suppuration at 
the wound, and the cause of death was not evident to naked-eye examination, 
at the autopsy. 

EXPERIMENT 532.—Five male, eight female and about 1,500 larval ticks, all 
living D. venustus, which had been used, or were the progeny of those used, 
in the above feeding experiments, were ground up, shaken and filtered in the 
same way as in Experiment 531. Respectively, 2 c.cm., 4.5 c.cm. and 6 c.cm. 
of the clear filtrate obtained was inoculated beneath the skin over the rump 


TODD—TICK PARALYSIS 63 
of three young rats, each weighing about 30 gm. All of the rats survived; 
in none did paralysis appear. 

EXPERIMENTS 550-551.—Three boxes, each containing a female D. venustus, 
and young seed ticks from her, were obtained from the Bitter Root Valley 
through the courtesy of R. A. Cooley, Esq. In two of the boxes the females 
and many hundreds of seed ticks were dead; in the third box the female and 
seed ticks were living. All were ground up together in 50 c.cm. of normal 
saline solution, shaken for two hours and then passed through Buchner and 
Berkefeld filters. About two-thirds of the whole filtrate obtained was inocu- 
lated subcutaneously over the withers of a 4%-months old lamb; 3.5 c.cm. of 
the filtrate was inoculated subcutaneously over the rump of a young white 
rat. Paralysis was never observed in either of these animals. 

It has been proved (Nuttall and Strickland, 1908) that ticks secrete 
an anticoagulin which prevents blood from clotting. Observations 
were, therefore, made to ascertain whether an anticoagulin existed in 
the filtrate of extracted ticks, which was inoculated into the animals 
used in Experiments 380, 400, 531 and 532. Blood from a healthy 
man was drawn up into capillary tubes, of about 1 mm. internal diam- 
eter, with one-third, occasionally one-fourth, of its volume of the fil- 
trate to be tested. A control tube was made in every instance, in which 
a 4 per cent. solution of glycerin was substituted for the filtrate. The 
tubes were then kept at room temperature, and the time in which the 
blood of each coagulated was observed. The tick extract used in 
Experiments 380 and 400 seemed to have no definite power of prevent- 
ing coagulation, since coagulation usually occurred in both tubes in the 
same length of time. The tick extracts used in Experiments 532 and 
531 had a definite, though slight, power of preventing coagulation. 
That used in Experiment 532 was definitely more powerful than that 
used in Experiment 531; with it, coagulation had usually only com- 
menced at the end of three minutes, while it was complete at the end 
of that time in the control tubes. It is possible that the lack of symp- 
toms obtained by the inoculation of the filtrates, as well as the lack of 
coagulating power of the filtrates used in Experiments 380, 400 and 
531, may be explained in part by the comparatively large quantity of 
diluent in which the ticks were extracted. It must also be remembered 
that only in Experiment 532 was the extract made from living ticks. 

It can be concluded that an extract of ticks, prepared in the manner 
described, will not cause paralysis in rats even when it possesses slight 
power to prevent the coagulation of human blood. 


SUMMARY 


1. Previous publications have proved: 

(a) That a paralysis in children may be associated with the bites 
of ticks in western North America and in Australia. 

(b) That a paralysis of sheep has been associated with the bites of 
ticks in British Columbia and in South Africa. 


64 THE JOURNAL OF PARASITOLOGY 


(c) That the ticks associated with these affections are of more 
than one sort. 

(d) That Dermacentor venustus has produced paralysis in lambs 
and in a puppy in experiments made under laboratory conditions. 

(e) That the paralysis following tick-bite is probably an individual 
and novel condition. 


2. The paralysis of children is not infrequently accompanied by 
elevation of temperature and by other constitutional symptoms; it is 
possible that symptoms resembling those observed in children some- 
times may appear in adults who have been bitten by ticks. 


3. Under experimental conditions by no means every tick bite pro- 
duces paralysis in laboratory animals. 


4. A weak extract of ticks will not cause paralysis when injected 
into white rats, even though it possesses definite power to prevent the 
coagulation of blood. 

REFERENCES 


Banks, Nathan. 1908. A Revision of the Ixodoidea or Ticks of the United 
States. U. S. Bur. Entom., Technical Series No. 15. 

Bishopp, F. C., and King, W. V. 1913. Additional Note on the Biology of 
the Rocky Mountain Spotted-Fever Tick. Jour. Econ. Entom., 6. Abstr. in 
Trop. Dis. Bull., 2: 203-6. 

Cleland. 1912. Austral. Med. Gaz., 32: 295-296. Abstr. in Trop. Dis. Bull., 
2: 203-6. : 

Eaton, E. M. 1913. A Case of Tick Bite Followed by Wide-Spread Tran- 
sitory Muscular Paralysis. Austral. Med. Gaz., 33: 391-394. Abstr. in Trop. 
Dis. Bull., 2: 203-6. 

Hadwen, S. 1913. On “Tick-Paralysis” in Sheep and Man, Following Bites 
of Dermacentor venustus. Parasitol., 6: 283-297. 

Hadwen, S., and Nuttall, G. H. F. 1913. Experimental “Tick-Paralysis” in 
the Dog. Parasitol., 6: 298-301. 

Nuttall, G. H. F. 1914. “Tick Paralysis” in Man and Animals. Parasitol., 
7: 95-104. 

Nuttall, G. H. F., and Strickland. 1908. On the Presence of an Anticoagulin 
in the Salivary Glands and Intestines of Argas persicus. Parasitol., 1: 302-310. 

Temple, I. U. 1912. Acute Ascending Paralysis or Tick Paralysis. Med. 
Sentinel (Portl., Ore.), 20: 507-514. 

Todd, J. L. 1912. Does a Human Tick-Borne Disease Exist in British 
Columbia? Jour. Can. Med. Assn.,.n. s., 2: 686. Abstr. in Trop. Dis Bull. 
2: 203-6. Tick Bite in British Columbia. Jour. Can. Med. Assn., n. s., 1912, 
2: 148-149. Abstr. in Trop. Dis. Bull., 2: 203-6. 


LARVAL TREMATODES FROM NORTH AMERICAN 
FRESH-WATER SNAILS 


PRELIMINARY REPORT * 


WILLIAM WALTER CorT 
Department of Biology, Macalesier College 


Almost nothing is known of the life histories of the trematodes 
of North America. Some progress has been made in the study of the 
adults, but as yet there are only a few scattered observations on larval 
stages. During the fall of 1913 the study of the larval trematodes 
from fresh-water snails was undertaken by the writer at the suggestion 
of Prof. Henry B. Ward, as an attempt to open up this undeveloped 
field. The snails studied, which were obtained from several sources, 
yielded a surprisingly large number of species of cercariae, belonging 
to a wide variety of trematode groups. Fourteen new cercariae with 
their sporocysts or rediae were studied in detail, especial attention 
being given to observations on the living animals. The complete 
results of this work, embodying a detailed discussion of anatomy, 
histology and relationships, will appear shortly. The present report 
contains some of the more interesting observations on the structure 
and activity of these forms. 

In the grouping of the cercariae the classification of Lithe (1909: 
173-210) has been followed in most instances. In those groups in 
which the structure of the cercaria corresponds fairly closely to that 
of the adult, as in the amphistomes and the echinostomes, this classi- 
fication is very satisfactory, but in those divisions where larval adapta- 
tions dominate the structure and where little is known of further 
development, as, for example, in the Stylet cercariae or microcercous 
group, the arrangement is certainly to some extent purely artificial. 

Of the fourteen cercariae studied, one is a monostome, two are 
amphistomes and the rest belong to five different subdivisions of the 
distomes. : 
MONOSTOME CERCARIAE 

Rediae and cercariae of a monostome, which I propose to name 
Cercaria urbanensis, were found during December 1913, in the livers 
of 5 per cent. of the full-grown specimens of Physa gyrina Say, from 
a drainage ditch near Urbana, Ill. There were present in the infected 
livers immature and fully developed rediae and free cercariae in dif- 


_ * Contributions from the Zoological Laboratory of the University of Illinois, under the 
direction of Henry B. Ward, No. 35. 


66 THE JOURNAL OF” PARASITOLOGY 


ferent stages of development. No rediae were present in which other 
rediae were developing and no mature cercariae remained in the rediae. 

When freed from the liver of the snail the redia of this species 
has considerable power of extension and contraction, the immature 
ones especially stretching out the anterior end and reaching in all 
directions. No locomotor appendages were present in any stage and 
no locomotion was noted. In shape they are elongate sacs, smallest 
at the anterior end and widest in front of the posterior extremity. 
The intestine is voluminous, having a diameter of from one-third to 
two-thirds the width of the body and reaching almost to the posterior 
extremity. 


Fig. 1—Mature Cercaria urbanensis, ventral view. Cystogenous glands not 
shown. X 140. 


The methods of locomotion of Cercaria urbanensis (Fig. 1), either 
when swimming in open water or when creeping on a substratum, are 
very striking. The body when swimming is contracted into a round 
ball and the powerful tail is curled ventrad and lashes with great 
rapidity driving the animal with considerable speed through the water. 
In spite of the absence of a ventral sucker, the cercaria is able to creep 
by utilizing two projections which form the posterior lateral angles of 
the body. These projections, which are reinforced by cuticular struc- 


CORT—LARVAL TREMATODES FROM SNAILS 67 


tures, are thrust against the surface in a manner analogous to setae 
and aided by the oral sucker push the animal along. Cercaria urban- 
ensis encysts in the open and the complete process of encystment was 
followed under the microscope. 

The shape of Cercaria urbanensis is quite variable. An individual 
may contract until its length is 0.27 mm. and its width 0.20 mm., and 
it may extend itself to 0.54 mm. in length and 0.11 mm. in width. The 
tail changes its length from 0.20 mm. to 1.2 mm. The histological 
structure of this tail is very interesting on account of its adaptation 
for powerful movement. The structure of this cercaria agrees in a 
general way with that of a group of closely related monostomes of 
which Cercaria imbricata Looss (Looss, 1896: 192-197), and Cercaria 
ephemera Nitzch (Ssinitzin, 1905, Plate 4, Figs. 75 and 76), are 
examples. It differs from these forms in details of structure, such as 
the length of the intestine of the redia and the structure of the loco- 
motor projections of the cercaria. Cercaria hyalocauda Haldeman, a 
monostome cercaria from North America, as described by Evarts 
(1880) is considerably larger than Cercaria urbanensis. 


AMPHISTOME CERCARIAE 


Amphistome cercariae are very easily recognized by the presence 
of the large acetabulum at the posterior end of the body. Although 
large numbers of adults of this type have been reported, but three cer- 
cariae are found in the literature, namely, the cercaria of Diplodiscus 
subclavatus (Goeze), best described by Looss (1892: 162-166) ; Cer- 
caria pigmentata Sonsino, which was shown by Looss (1896: 185-191) 
to be the larval form of Paramphistomum cervi (Zeder), and the cer- 
caria described by Looss (1896: 177-185) as the larval form of Gas- 
trodiscus aegyptiacus. Of these cercariae that of Paramphistomum 
cervi belongs to the subfamily Paramphistominae, and the other two 
to the Diplodiscinae. My studies add to the second subfamily two 
cercariae, which differ from the known forms in details of structure 
both of the redia and cercaria. 

These two cercariae were collected from specimens of Planorbis 
trivolvis Say, from three localities. Two snails out of eighteen of this 
species from Lawrence, Kan., and one from large numbers examined 
from around Urbana, IIl., contained the first of these forms, a large 
pigmented cercaria, to which the name Cercaria inhabilis is given. The 
second, a small unpigmented cercaria, Cercaria diastropha, was found 
in one of twenty specimens of Planorbis trivolvis from a small pond in 
the suburbs of Chicago. In all the infected snails adult and immature 
cercariae were found free in the livers, the mature forms being nearest 
the periphery, and the active rediae contained no fully developed cer- 


68 THESSOURNAL (ORF PARASTTOLOGY 


cariae. There were no sporocysts present and no rediae in which 
rediae were developing. 

The rediae of Cercaria inhabilis were all in about the same stage of 
development. When freed from the snail they were very mobile, 
extending and contracting and making some progress even on the 
smooth surface of a watch glass. There are present two pairs of 
locomotor appendages and the posterior extremity is attenuated and 
pointed. The pharynx is small in proportion to the size of the body 
and the intestine is voluminous and extends more than one-third of 
the distance from the anterior to the posterior ends. 

Cercaria inhabilis (Fig. 2) swims sluggishly in open water. It 
contracts its body and lashes rapidly with its tail moving forward in 
an unwieldy irregular fashion. In fact, the body is too large in pro- 
portion to the size of the tail for rapid locomotion. On a substratum 
the cercaria extends and contracts its body, but is unable to creep with 
the aid of the suckers. It is the largest of the cercariae studied. In 
the different stages present the development of the pigmentation could 
be traced from little spots around the eyes until it spread through most 
of the body. Although cystogenous glands are highly developed, filling 
most of the body, none of the cercariae under observation were seen 
to encyst. 

Cercaria diastropha (Fig. 3) resembles Cercaria inhabilis in general 
structure. It differs from this form in the size and shape of the body, 
the ratio in the size of the suckers and in the position of the acetabu- 
lum, in the amount of pigmentation, and in the anlage of the repro- 
ductive organs. 

The redia of Cercaria diastropha is even more active than that of 
the former species, being able to move well with the aid of the two 
pairs of locomotor appendages and to stretch to five or six times its 
usual length. This mobility is correlated with extreme development 
of the circular muscles, which show clearly externally as annular rings. 

The only adult trematode from North America which resembles 
these amphistome cercariae in structure is Diplodiscus temporatus 
Stafford. Cary (1909) described as belonging to the life history of 
this species sporocysts and rediae, both containing cercariae from 
Goniobasis virginica obtained near Princeton, N. J. In 1911 Cary 
kindly sent me some of the material used in the preparation of this 
paper, including specimens of Diplodiscus temporatus from his experi- 
mental tadpoles. A study of this material and a careful analysis of 
Cary’s account shows that he has described as belonging to this species 
two entirely different types of cercariae, that is, a large gymnocephal- 
ous cercaria developing in rediae and a small xiphidiocercaria develop- 
ing in sporocysts. Since in his infection experiments he used only the 


CORT—-EARVAL TREMATODES FROM SNAILS 69 


larger species, he certainly can have no evidence that the smaller form 
has any connection with Diplodiscus temporatus. Therefore, Cary’s 
whole discussion in the embryological part of the paper (1909: 617- 
647) which is based on the study of the sporocysts and the cercariae 
developing in them, cannot without further evidence be given a place 


(iss 


Fig. 2—Mature Cercaria inhabilis, ventral view. Cystogenous glands not 
shown. X 88. 


in the life history of Diplodiscus temporatus. However, it proves the 
thesis which Cary sets out to make that the embryo in the sporocyst 
develops from parthenogenetic eggs, and is therefore a very important 
contribution to trematode embryology. I am convinced that the larger 
form, which I shall call Cercaria megalura, is not the cercaria of 


70 THE, JOURNAL OFF PARASITOLOGY 


Diplodiscus temporatus, as Cary maintains, because it is so funda- 
mentally different in structure from all known amphistome cercariae 
and from the adult of this species. Further, Cary’s infection experi- 
ments are not sufficiently controlled to be conclusive and admit of an 
entirely different interpretation from the one he gives. To produce 
infection he puts the tadpoles into jars with snails which contain these 
cercariae and because the tadpoles were later found to be infected with 


Fig. 3—Mature Cercaria diastropha, ventral view. Cystogenous glands not 
shown. X 176. 


Diplodiscus temporatus, he concluded that these trematodes had devel- 
oped from cercariae in the snails. The first adults were found one 
week after the beginning of the experiments. These cercariae are so 
fundamentally different from the adults into which Cary supposed that 
they developed in one week's time, that I am convinced that he is in 
error in-his conclusions and that the experimental tadpoles, in spite of 


CORT—LARVAL TREMATOBDES FROM SNAILS 71 


the checks which he used, were already infected with Diplodiscus tem- 
poratus. Lack of space admits in this report of only the bare outlines 
of the conclusions in this matter. A full discussion of the data and 
arguments which have led to the above conclusions will be published in 
the final paper. 

The smaller of Cary’s two species of cercariae I shall call Cercaria 
caryi (Fig. 4). Since it is very small and no living material is avail- 
able for study, no extended description will be attempted. It evidently 
belongs to Lithe’s group of Cercariae microcotylae under the Xiphidio- 
cercariae. I was fortunate enough to obtain further material of Cer- 
caria megalura, so that a detailed study was possible. Some facts con- 
cerning this form and certain corrections of Cary’s description will be 
given here. 

DISTOME CERCARIAE 


The great bulk of known cercariae belong in this division. In my 
material were eleven distome cercariae representing five of the sub- 
groups. 


Fig. 4—Mature Cercaria caryi, ventral view. From Cary’s material. X 280. 


Gymnocephalous Cercariae 


Since beyond the fact that they develop in rediae the cercariae 
placed in this subdivision agree only in the absence of certain char- 
acters, it is probably an unnatural group. However, in the present 
state of our knowledge it is very convenient to retain it. From my 
material only Cercaria megaluria, wrongly described by Cary as the 
larva of Diplodiscus temporatus, belong here. 

Rediae containing cercariae of this species were found in one from 
seventy-three specimens of Pleurocera elevatum Say, from the Sanga- 
mon River near Mahomet, Ill. This species, as Cary entirely failed to 

.note, resembles very closely in both activity and structure Cercaria 
distomatosa Sonsino, best described by Looss (1896: 197-204). These 
two species differ in the size and the relations of the digestive system 
of the redia and in the size of the cercaria and in the relations of its 
excretory system. Since they differ very greatly from all others of the 


72 THE. JOURNAL.\OF, PARASITOLOGY 


gymnocephalous group, I propose to make them the basis of a sub- 
group, to which the name Megalurous cercariae may be given. 

The rediae of Cercaria megalura are very active and the region 
back of the locomotor appendages on account of its mobility and atten- 
uation resembles a tail. The anterior region of the body can be 
extended and contracted freely and with the aid of the locomotor 
appendages locomotion was possible. The intestine is very volumin- 
ous, being from one-third to two-thirds the diameter of the body and 
reaching almost to the posterior tip. 


Fig. 5—Mature Cercaria megalura, ventral view. (a) Before extrusion of 
cystogencus material. X 195. (b) After extrusion of cystogenous material. 
X 195. 

Cercaria megalura (Fig. 5a) is unable to use its tail for swimming 
in open water, but on a surface creeps fairly rapidly with the aid of 
the suckers. At times the cercaria becomes attached by the tip of its 
tail which is furnished with an adhesive organ. It then becomes 


CORT—EARVAL TREMATODES FROM SNAILS 73 


extended to five or six times its usual length and is greatly attenuated. 
In this position it moves continually with a wriggling serpentine 
motion, which makes it resemble a tubificid worm. This activity prob- 
ably aids in transfer to a secondary intermediate host. None of the 
cercariae were seen to encyst, although large numbers of them extruded 
cystogenous material in the form of a sort of open tube around the 
body (Fig. 5b). 

The study of both Cary’s and my own material of Cercaria megal- 
ura shows that he is in error in his description of the digestive system, 
the tail, and the anlage of the reproductive organs as is evident on 
comparison of Cary’s Figure 6 of Plate 30 with Figures 5a and 5b of 
this paper. 


Fig. 6—Mature Cercaria trivolvis, ventral view, cystogenous glands not 
shown. X 195. 


Echinostome Cercariae 


Cercariae belonging to the family Echinostomidae are very easily 
recognizable because of the presence as in the adult of the anterior 
collar and crown of spines. The structure of the excretory and diges- 
tive systems are also very characteristic for the whole group. The 
anterior crown of spines gives a very definite basis for comparison 
between larvae and adults, and many suggestions of life histories have 
been made on this character. 


74 THE JOURNAL Of PARASITOLOGY 


Two cercariae of this group were found in the material studied. 
In neither of them are the anterior spines like any of the known 
American adult echinostomes, and they differ in a number of points 
from any of the cercariae of this group described. 

Rediae in which cercariae were developing, as well as encysted 
cercariae of the first of these species, for which the name Cercaria 
trivolvis is proposed, were found in several specimens of Planorbis 
trivolvis from Urbana, Ill. Planorbis trivolvis is able, then, to serve 
both as intermediate and secondary intermediate host for this trema- 
tode. The second echinostome species, Cercaria rubra, was found 
encysted in six out of thirty-six specimens of Campeloma subsolidum 
Anthony, from Hartford, Conn. The snail in this case is merely the 
secondary intermediate host. ; 


Fig. 7—Cercaria rubra. (a) Freed from cyst, ventral view. X 195. (bd) 
Anterior end of cercaria, dorsal view. X 390. 


The rediae of Cercaria trivolvis are much like those described for 
other echinostomes, differing from them only in details of structure. 

The cercaria (Fig. 6) of this species moves actively, both by swim- 
ming in open water and by creeping on a surface. The tail is powerful 
and extends when the anima! is swimming to two or three times the 
length of the body. For the swimming movement the cercaria bends 
ventrad almost double, with the posterior half of the body above the 
anterior. The tail, which extends out beyond the anterior end, lashes 
vigorously and propels the animal rapidly. Of all the cercariae 


CORT—LARVAL TREMATODES FROM SNAILS Zs 


observed only Cercaria urbanensis moved more rapidly than Cercaria 
trivolvis. 

The crown of spines of Cercaria trivolvis consists of thirty-seven 
spines of equal size, arranged in two alternate rows which are broken 
in the middle of the ventral surface. The two or three nearest the 
midline on each side of the ventral surface point in. An idea of the 
general structure of this cercaria can be gained from the figure. 

Cysts of Cercaria rubra were large and thick walled. The worm 
almost completely fills the cyst and moves only slightly. Worms were 
freed from the cysts and their structure studied (Fig. 7a and 7b). 
Most typical is the arrangement of the spines in the anterior collar. 
There are forty-three spines of uniform size arranged in two alternate 
rows. The four on each side nearest the midline of the ventral surface 
point inward. 


Fig. 8—Mature Cercaria reflexae, ventral view. Cystogenous glands not 
shown. X 88. 


As an appendix to the Echinostome cercariae I treat the following 
form: The livers of eight out of thirty-eight specimens of Lymnaea 
reflexa Say, from Chicago, contained rediae in which were developing 
a species of cercaria, for which the name Cercaria reflexae is proposed. 
Also in the body cavities of a number of the same snails were encysted 
cercariae of the same species. 


Cercaria reflexae (Fig. 8) agrees with the echinostomes in the gen- 
eral structure of the redia, and in the method of locomotion and struc- 
ture of the excretory and digestive systems of the cercaria. However, 


76 LHE JOURNAL. ORMPARASTITOLOGY 


it lacks entirely the anterior cellar and crown of spines typical of the 
echinostomes. No record has been found of any species, either cer- 
caria or adult, that corresponds in structure to this species. 


Microcercous Cercariae 


The group of microcercous cercariae includes a very heterogeneous 
collection. Some of them develop in rediae and some in sporocysts. 
Some have stumpy tails developed as suckers and some have merely 
blunted tails. Dollfus (1913) has already formed within this group a 
subdivision, the Cotylocercous cercariae, which contains a number of 
marine forms, centering around Cercaria pachycerca Diesing, with 


Fig. 9—Mature Cercaria trigonura, (a) ventral view. X 260. (b) ,Stylet 
of same. X 866. 


their tails developed as suckers. Whether there is any close relationship 
between the members of this group and the other forms now included 
within the microcercous cercariae is impossible to determine in the 
present state of our knowledge. It is therefore best to retain the name 
microcercous cercariae provisionally to cover all short-tailed forms 
which do not fit into other groups. 

Such a cercaria was found in four out of the thirty-six specimens 
of Campeloma subsolidum from Hartford, Conn. The tissues of the 
body above and at the bases of the gills of these snails contained large 
numbers of free mature cercariae. There were also present rediae in 


CORT—LARVAL TREMATODES FROM SNAILS 77 


different stages of development in which only little differentiated germ 
balls could be distinguished. 

This cercaria (Fig 9 a), for which I propose the name Cercaria 
trigonura, has an elongate cylindrical body and a very short heart- 
shaped tail. It is unable to swim freely in open water, but extends and 
contracts its body very rapidly. The tail bent ventrad and pushing 
against the substratum aids somewhat in locomotion and the oral 
sucker at times becomes attached. By this peculiar method the animal 
is able to make a little progress with a great deal of effort. 

On the ventral surface of Cercaria trigonura, just at the base of 
the tail, is a slit-like opening, which extends forward a short distance 
and dorsad reaches up into the body. Opening into the cavity thus 
formed are large numbers of unicellular glands which stain very 
heavily with hematoxylin. The position and structure of this posterior 
gland suggests that it may function for adhesion. No activity which 
suggests such a function has been observed. Figure 9a shows the 
characteristic shape of the stylet of this species. The large bicornuate 
excretory vesicle lined with a layer of granular cuboidal epithelial cells 
is also characteristic. 


Cercaria trigonura is unique among the microcercous cercariae in 
having a large posterior gland opening at the base of the tail and in its 
bicornuate excretory bladder. It differs from all except Cercaria 
limacis Moulinié (1856: 83, 163-164), in having a blunted tail which is 
not modified as a sucker. 


Furcocercous Cercariae 


The Furcocercous or forked-tailed cercariae are very imperfectly 
known. Although at least a dozen species have been reported as dis- 
tinct, the anatomy of only a few of them is at all well worked out and 
the life history of no one of them has been determined. 

Tangled masses of sporocysts containing a cercaria of this type 
were found in the livers of five out of the thirty-six specimens of 
Lymnaea reflexa from Chicago. The name Cercaria douthitti is pro- 
posed for this form. The sporocysts are long cylindrical tubes of 
varying caliber which are unbranched and very much tangled together. 
When the cercariae were freed from the sporocysts they moved around 
somewhat erratically by a vigorous vibration of the body and tail. The 
oral sucker was not fully developed, so that the creeping movement 
could not be accomplished. 

Cercaria douthitti (Fig. 10) is a small cylindrical cercaria with 
eyespots and a tail considerably longer than its body. Although it has 
no stylet, the region back of the acetabulum is almost completely filled 
with eight large unicellular glands, which seem to be analogous to the 


78 THE JOURNAL OF PARASITOLOGY 


stylet glands in certain other forms. Two groups of ducts from these 
glands run forward along each side and pass through the oral sucker 
to open at the anterior tip. 

Only one forked-tailed cercaria, Cercaria ocellata La Valette St. 
George (1855: 22-23), resembles at all closely in structure Cercaria 
douthitti. Cerceria ocellata is, however, almost twice as large as my 
species and has fin-like projections on the divided lobes of the tail. 


Fig. 10—Mature Cercaria douthitti, ventral view. X 195. 


Xiphidiocercariae 

About one-third of all the known cercariae belong to the Xiphidio- 
or stylet cercariae. They are characterized as slender-tailed distome 
cercariae with a boring spine. As this group contains a large variety 
of forms, numerous subdivisions have been proposed. In my material 
are found five new stylet cercariae of four different types. Two of 
them are so much alike and agree so closely with several European 
cercariae that it is proposed to unite them into a new subgroup, which 
will be discussed next. 


CORT—LARVAL TREMATODES FROM SNAILS 79 


Polyadenous Cercariae 


The name Polyadenous cercariae is proposed as a group designa- 
tion for those of the Xiphidiocercariae which agree in the following 
characters. 

1. Development in much elongate sac-shaped sporocysts. 

2. Tail slender and except when much extended less than body 
length. 

3. Acetabulum back of the middle of the body and smaller than the 
oral sucker. 


Fig. 11—Mature Cercaria isocotylea; (a) ventral view. X 415. (b) Stylet 
of same. X 5/7. 


4. Stylet about 0.030 mm. in length, six times as long as broad, 
and with a thickening about two-thirds of the distance from the base 
to the point. 

5. Stylet glands six or more on each side between the acetabulum 
and the pharynx. 

6. Excretory bladder bicornuate. 

Two European fresh-water cercariae, Cercaria limnaeae-ovatae von 
Linstow, and Cercaria secunda Ssinitzin, can without question be 
placed in this group. I am able to add two American species, Cercaria 
isocotylea and Cercaria polyadena. 

Cercaria isocotylea (Fig. 1la) was found in elongate, must twisted 
cylindrical sporocysts in 18 per cent. of 170 specimens of Planorbis 


80 THE SOURNALE: OP SPARASITOLOGY 


trivolvis from a drainage ditch northeast of Urbana, Ill. This cercaria 
moves actively both by swimming in open water and on a surface 
where it creeps with the aid of the suckers. When swimming, the 
body, which is turned with the dorsal side down, is bent slightly ventrad 
and the tail, which moves almost in a vertical plane, lashes rapidly. 
The locomotion is not very rapid and somewhat erratic. 

This cercaria, except when much extended, is under 0.20 mm. in 
length. The tail is considerably shorter than the body and very slender. 
The acetabulum is almost as large as the oral sucker. The character- 


Fig. 12.—Mature Cercaria polyadena; (a) ventral view. Cystogenous glands 
not shown. X 415. (b) Stylet of same. X 577. 


istic stylet is shown in Figure 11b, and the stylet glands form two 
groups of from six to eight in a group. 

Cercaria polyadena (Fig. 12a), the second polyadenous form, was 
found in one of the specimens of Lymnaea reflexa from Chicago, 
which was also infected with Cercaria reflerae. The cercariae were 
contained in elongate unpigmented sporocysts, much like those of the 
former species. The movement of this cercaria is much like that of 
Cercaria isocotylea, and its stylet (Fig. 12b) is very similar to that of 
that species. It has, however, a larger body and tail, a smaller acetab- 
ulum and a larger number of stylet glands than Cercaria isocotylea. 


CORT—LARVAL TREMATODES FROM SNAILS 81 


Some facts are known of the further development of the polyaden- 
ous cercariae. Cercaria limnaeae-ovatae has been assigned to Opis- 
thioglyphe rastellus (Olson), and Ssinitzin (1905) suggests that Cer- 
caria secunda may be the larva of a Plagiorchis species. It is possible, 
therefore, that the American forms belong to Lihe’s subfamily Plagi- 
orchiinae. 

Microcotylous Cercariae 


Luhe’s group of Cercariae microcotylae contains a number of very 
small Xiphidiocercariae, most of which are very insufficiently known. 
Besides the forms listed by Luhe (1909: 196-198) and Cercaria caryi, 


Fig. 13—Immature Cercaria leptacantha, ventral view. X 433. 


three Egyptian cercariae of Looss (1896: 227-232), Cercaria cellulosa 
sp. ing., Cercaria pusilla sp, ing. and Cercaria exigua sp. inq., should 
be placed in this group. An American species to be called Cercaria 
leptacantha is added from my material. The tissues above the gills in 
three of the thirty-six specimens of Campeloma subsolidum from Hart- 
ford, Conn., was infected with oval thin-walled sporocysts containing 
cercariae of this species. 

The general structure of Cercaria leptacantha is shown in Figure 13. 
None of the cercariae were fully matured and but slight movement 
was noted. 


82 THENVTOCRNAL, OR BPARASITOLOGY 


Cercariae Ornatae 


Luhe (1909: 190) defines the Cercariae ornatae as follows: “Dis- 
tome Cercariae mit Bohrstachel, deren schlanker Ruderschwanz einen 
Flossensaum besitzt.” . 

In this group are placed Cercaria ornata La Valette, and Cercaria 
prima Ssinitzin. From my material an American form, Cercaria 
hemilophura, is added. This group must very evidently be considered 
as merely provisional, since the three cercariae comprising it are very 
different in structure, having little in common except the presence of a 
fin-like projection from the tail. 

A tangled mass of elongate, orange-pigmented sporocysts contain- 
ing cercariae of Cercaria hemilophura were found in one of twenty 


Fig. 14—Mature Cercaria hemilophura; (a) ventral view. Cystogenous 
glands not shown. X 140. (0b) Stylet of same. X 433. 


specimens of Physa gyrina from Rockford, Ill. The sporocyst tubes 
do not branch and are of varying caliber. Club-shaped ends jut out 
from the mass and sway slightly backward and forward. 

Cercaria hemilophura (Fig. 14a) is a large cercaria, over 0.40 mm 
in well-extended specimens, and its tail is about the length of the body. 
Along the ventral surface of the posterior half of the tail extends a 
fin-like projection which at its widest is about half the width of the 
tail. The stylet (Fig. 14b) is small, tapers regularly to a point and has 
no thickened region. The body contains large numbers of cystogenous 
glands, but no stylet glands could be distinguished. Other points of 
general structure can be made out from the figure. 


CORT—LARVAL TREMATODES FROM SNAILS 83 


The livers of three out of ninety-three specimens of Physa anatina 
from Manhattan, Kan., contained sausage-shaped sporocysts in which 
a peculiar kind of Xiphidiocercaria was developing. For this species 
the name Cercaria brevicaeca is proposed. No cercaria has been found 
in the literature which corresponds closely to this form. 

The specimens of Cercaria brevicaeca examined moved clumsily 
and irregularly while swimming. Figure 15a shows the general points 
of structure. Very characteristic of this species is the stylet (Fig. 15b). 
Of the excretory system only the peculiarly shaped vesicle can be made 
out. This is composed of a pyriform median portion and two lateral 
parts which almost completely surround the acetabulum. Numerous 
cystogenous glands and two clumps of from ten to twelve stylet glands 


are present. 
{} 


Fig. 15—Free-hand drawing of Cercaria brevicaeca; (a) ventral view. 
Cystogenous glands not shown. X 150. (0b) Stylet of same. X 433. 


SUMMARY 


Fourteen new cercariae were found in six species of fresh-water 
snails obtained from seven localities. 

Of these one is a monostome, two are amphistomes and the others 
belong to five of the groups under the distomes. 

Observations on the living cercariae show interesting locomotor 
activities. 

The two amphistome cercariae described correspond closely in 
structure to Diplodiscus temporatus Stafford. Two different cercariae, 
one a large gymnocephalous form and the other a small stylet cercaria, 
which Cary described as being this species cannot belong to it. 


84 Tae JOURNAL Of PARASITOLOGY 


A new subgroup of gymnocephalous cercariae, the megalurous or 
heavy tailed cercariae, is proposed ; it includes Cercaria megalura from 
Pleurocera elevatum and Cercaria distomatosa Sonsino. . 


Cercaria polyadena and Cercaria isocotylea are made the basis of 
the polyadenous cercariae, a new subgroup of the xiphidiocercariae. 


LITERATURE CITED 


Cary, L. R. 1909. The Life-History of Diplodiscus temporatus Stafford, 
Zool. Jahrb., Abt. f. Anat. u. Ont., 28: 595-659. 


Dollfus, R. 1913. “Cercaria pachycerca” Diesing et les Cercaires 4 queue 
dite en moignon. Int. Zool. Congr., Monaco, pp. 683-685. 

Evarts, H. C. 1880. Cercaria hyalocauda Haldeman. Am. Month. Micr. 
Jour., 1: 230-232. 

La Valette, St. George. 1855. Symbolae ad trematodum evolutionis his- 
toriam. Berolini, p. 38. 

Looss, A. 1892. Amphistomum subclavatum und seine Entwicklung, Leuck- 
art’s Festschr., pp. 147-167; 1896. Recherches sur la faune parasitaire de l’Egypt. 
Mem. de I’Inst. Egypt., 3: 1-252. 

Lithe, M.: Parasitische Plattwiirmer. 1. Trematodes. Siisswasser Fauna 
Deutschlands, Heft 17. 


Moulinié, J. J. 1856. De la reproduction chez les Trématodes endopara- 
sitaire. Mem. l’Inst. Genevois, 3: 1-279. 


Ssinitzin, D. Th. 1905. Contributions to the National History of Trema- 
todes. The Distomes of Fish and Frogs in the Vicinity of Warsaw, p. 210 
(Russian). ‘ 


NEW VARIETIES AND SPECIES OF MALARIA 
PLASMODIA * 


CHARLES F. CRAIG 
Captain, Medical Corps, U. S. Army. 


Although it has been nearly twenty-four years since Laveran 
announced his discovery of the parasites concerned in the etiology of 
the malarial fevers, and although an immense amount of work has been 
expended on the study of these parasites in the endeavor to arrive at 
a classification of them that can be accepted by all observers, we are 
still far from achieving that happy result, as is readily evident if one 
compares the classifications given by the authors of the most recent 
works on the subject. While most authorities agree that there are at 
least three species of malaria plasmodia, they do not all agree as 
regards nomenclature, and Laveran still adheres to the belief in the 
unity of all malaria plasmodia occurring in man, regarding the so-called 
species as variations in a single pleomorphous species. 

In view of the evidence that has accumulated regarding the mor- 
phology, life cycle and relation to disease of the plasmodia of malaria, 
I believe, with most investigators, that several species of malaria 
plasmodia exist. The marked differences in the morphology of the 
species generally accepted, which are constant; the length of their 
cycle in man; the symptoms produced by their presence and the 
periodicity of the occurrence of these symptoms, all point to the con- 
clusion that we are dealing with different species, while the fact that 
each plasmodium reproduces its kind when experimentally inoculated 
into man and with that reproduction gives rise to the characteristic 
clinical symptoms commonly produced by the species inoculated, makes 
the evidence in favor of distinct species practically conclusive. When 
to these evidences is added the fact that certain species of mosquitoes 
can only transmit certain species of the plasmodia, the evidence would 
appear to be incontrovertible. 

As a matter of fact, Laveran is practically alone in his advocacy 
of the unity of the human malaria plasmodia, for the consensus of 
opinion among protozoologists is in favor of the plurality of species. 
While this is so, there is still considerable disagreement regarding the 
number of species which should be recognized and the classifications 


* From the Department Laboratory, Central Department, U. S. Army, Fort 
Leavenworth, Kan. 
* Published with authority of the Surgeon-General, U. S. Army. 


86 THE JOURNAL OF PARASITOLOGY 


of Grassi and Feletti (1890), Mannaberg (1899), Sacharoff (1896), 
Lithe (1900), Schaudinn (1902), Doflein (1911) and others differ 
somewhat in this respect, although the majority recognize at least 
three species, the tertian, quartan and estivo-autumnal plasmodia. The 
names given these species also vary with different authorities, but if 
the generally accepted rules of nomenclature be followed, the tertian 
plasmodium must be called Plasmodium vivax (Grassi and Feletti), 
the quartan, Plasmodium malariae (Marchiafava and Bignami), and 
the estivo-autumnal, Plasmodium falciparum (Welch). While, as has 
been stated, nearly all authorities admit the existence of the three 
species mentioned, there is still considerable discussion regarding the 
existence of still other species, especially of species of the estivo- 
autumnal plasmodium. By many observers the plasmodia encountered 
in the malarial fevers generally known as estivo-autumnal are divided 
into two species, the subtertian or tertian, and the quotidian, while 
by some the latter is divided into a pigmented and unpigmented quo- 
tidian plasmodium. 

During the past sixteen years I have had the opportunity of study- 
ing the plasmodia in thousands of cases of estivo-autumnal malaria 
and have reached the conclusion that two distinct species of plasmodia 
are concerned in the etiology of these forms of malarial fever, one 
sporulating in twenty-four hours, the other in forty-eight hours. These 
two species of plasmodia were first described by Marchiafava and 
Bignami, and there is no doubt in my mind that they can be distin- 
guished morphologically and that, in uncomplicated instances of infec- 
tion, they each produce a characteristic form of malarial fever. In 
previous communications (1901, 1909) I have described in detail the 
morphology and life cycle of these plasmodia and the symptoms pro- 
duced by infection with them, and further research has only convinced 
me of the truth of Marchiafava and Bignami’s classification of the 
estivo-autumnal plasmodia. Later (1909a) I proposed the name 
Plasmodium falciparum quotidianum for the quotidian species of the 
estivo-autumnal plasmodium, considering it a subspecies of the sub- 
tertian or tertian estivo-autumnal plasmodium, or Plasmodium falci- 
parum. Accordingly, at the present time, I believe that there are 
four well-defined species of malaria plasmodia, namely, Plasmodium 
vivax, the tertian; Plasmodium malariae, the quartan; Plasmodium 
falciparum, the subtertian or tertian estivo-autumnal, and Plasmodium 
falciparum quotidianum, the quotidian estivo-autumnal. 

Recently there have appeared contributions by two different 
observers describing new varieties or species of the malaria plasmodia. 
In view of the interest which must attach to the discovery of any new 
forms of these parasites in man, and as I believe that I have observed 


Se 


CRAIG—NEW MALARIA PLASMODIA 87 


plasmodia similar in every respect to those described in the contribu- 
tions mentioned, it has seemed of importance to place my observations 
on record together with some critical comments regarding the subject. 
In April, 1914, in the Proceedings of the Royal Society and in the 
Annals of Tropical Medicine and Parasitology, J. W. W. Stephens 
(1914, 1914a) described what he considered a new species of malaria 
plasmodia of man, while in May, 1914, in the Bulletin de la Société de 
Pathologie Exotique, Ahmed Emin described (1914) a plasmodium 
which he regarded as a variety of Plasmodium vivax, the benign ter- 
tian plasmodium. Stephens has named the plasmodium observed by 
himself Plasmodium tenue, while Emin has named his Plasmodium 
vivax variety minuta. Both contributions are well illustrated by pre- 
sumably correct drawings of the plasmodia described, else I would 
not feel justified in discussing the parasites, not having seen the actual 
preparations containing them. However, as I have repeatedly observed 
plasmodia answering in every detail to those described and illustrated 
in the papers referred to, I feel no hesitation in recording my observa- 
tions in confirmation of the existence of these forms, although I can- 
not agree with all that is noted regarding the so-called Plasmodium 
tenue in so far as its classification as a new species is concerned. The 
plasmodium described by Ahmed Emin will first be considered. 


PLASMODIUM VIVAX VARIETY MINUTA 


This plasmodium was observed in the blood of pilgrims in the hos- 
pital at Camaran, an island in the Red Sea, about 30 miles from 
Hodeidah. Emin describes the plasmodium as resembling the benign 
tertian plasmodium (Plasmodium vivax), but differing from it princi- 
pally in its smaller size, lack of enlargement of the infected erythro- 
cyte, and smaller number of spores or merogoites.. The pigment 
present in the plasmodium is fine and resembles that in Plasmodium 
vivax. At the time of sporulation the plasmodium almost entirely 
fills the erythrocyte, which is not enlarged, and from four to ten 
merozoites are produced by the division of the parasite. Ameboid 
motility is slight as compared with that of Plasmodium vivax. Multi- 
ple infection of the erythrocyte was not infrequently observed, and 
one of the drawings shows an erythrocyte containing as many as five 
schizonts in the “ring” stage of development. Emin believes that while 
there are marked differences between this plasmodium and Plasmodium 
vivax, it resembles the latter to such an extent that it should properly 
be regarded as a variety rather than a new species, and proposes the 
name Plasmodium vivax variety minuta. 

In 1899 and 1900, while studying the malaria plasmodia observed 
in the blood of our soldiers returning from the Philippines, at the 


88 THE, JOURNAL OF. PARASITOLOGY. 


U. S. Army General Hospital, Presidio of San Francisco, Cal., I 
observed a plasmodium in the blood of six patients answering to the 
description of the variety minuta of Emin, and my observations were 
published in the Report of the Surgeon-General of the Army (Craig, 
1900). Emin’s description of his plasmodium answers almost exactly 
to that of the plasmodia observed in these cases, and his drawings are 
accurate reproductions of the plasmodia that I observed. Since that 
time I have noted the same plasmodium in regions where only tertian 
infections are present, and I am in agreement with him in considering 
it to be a variety of Plasmodium vivax. The following is my original 
description of this plasmodium, as published in the Surgeon-General’s 
Report: 

“In studying the blood of soldiers returning from the Philippines 
and suffering from malaria, I have noticed in several cases a peculiar 
form of the malarial parasite which I have classified in reporting on 
the cases as a tertian parasite, but which presents so many differences 
from the ordinary tertian parasite as to indicate that it is a distinct 
variety of the plasmodium. 

“T have invariably observed it in the blood of patients having ter- 
tian paroxysms and always in large numbers. All stages of the para- 
site have been observed, from the hyaline disks to the segmenting 
bodies. It appears first as a very highly refractive circular hyaline 
disk within the erythrocyte, having a sharply cut outline and no ame- 
boid motion. The absence of ameboid motion differentiates it from 
all other young forms of the malarial parasites. The hyaline disk is 
about one-fourth the size of the infected corpuscle, which is normal 
in size and appearance. 

“In a few hours the hyaline disk has grown to about one-half the 
size of the corpuscle which contains it and has become pigmented. 
The pigment exactly resembles that found in the ordinary tertian para- 
site, being finely granular and motile and distributed unequally 
throughout the parasite. The parasite is circular in shape and devoid 
of ameboid motion. The border of the parasite is very sharply defined 
and the protoplasm very refractive and sometimes finely granular. 
The infected corpuscle is unaltered in size and color and is not crenated 
or shrunken. 

“In about thirty-eight to forty hours the parasite has nearly filled 
the corpuscle containing it, and the amount of pigment has increased. 
The parasite is circular in shape and presents the same refractive pro- 
toplasm and sharply cut border; the pigment is sluggishly motile, red- 
dish in color and in the shape of fine granules. The infected corpuscle 
is normal in size and color. 


CRAIG—NEW MALARIA PLASMODIA 89 


“T have not as yet observed the presegmenting forms in the blood, 
but have seen several segmenting forms. These are much smaller 
than the ordinary tertian segmenting forms, and the greatest number 
of segments observed has been ten. The segments are oval in shape 
or perfectly round, sharply cut and refractive. The pigment is usually 
collected in a solid reddish-brown mass at the center of the segmenting 
parasite and is immotile.” 

After giving the differential points between this parasite and the 
other species of malaria plasmodia, consisting chiefly in size, shape, 
ameboid motility, number of merozoites and character and arrange- 
ment of the pigment, I call attention to the fact that “The differentia- 
tion of this parasite from the quartan organism is really much more 
difficult than is the case with the tertian or estivo-autumnal plasmodia. 
Indeed, I mistook them for quartan parasites until the clinical his- 
tories of the cases and certain peculiarities of the parasites caused me 
to study them more carefully.” They differ from Plasmodium 
malariae in the lesser degree of ameboid motility, in the larger amount 
of and more finely granular pigment, and in having a human life cycle 
of forty-eight hours instead of seventy-two hours. In conclusion, 
I state: 

“T believe that this parasite is either a distinct variety of the 
malaria plasmodia or that it is a tertian parasite which has acquired 
the characteristics described through some unknown condition of 
environment acting on the development of the organism.” 

It will be noted that in my original description I mention that ame- 
boid motility was absent in this plasmodium, but further observations 
have proved that it is present, but very much less pronounced than 
in Plasmodium vivax. The round form of this plasmodium is well 
illustrated in Emin’s drawings and the number of merozoites men- 
tioned by him, four to ten, agrees exactly with my own observations, 
the largest number I have ever noted being ten. My original descrip- 
tion was based on the living organisms, but later observations on 
specimens stained with Wright’s modification of the Romanowsky 
stain confirm Emin’s description of the stained plasmodium. The 
chromatin stains very intensely and tends to collect near the periphery 
of the plasmodium after the latter is half grown and just before sporu- 
lation, while the pigment at this time collects at or near the center of 
the plasmodium, the merozoites frequently being arranged regularly 
around the mass of pigment, giving the plasmodium the typical daisy 
or “marguerite” appearance, often spoken of as being characteristic of 
the sporulating forms of Plasmodium malariae. 

Emin states that he could not be sure whether Schuffner’s dots 
occurred in the infected erythrocyte, but in my experience they do 


90 THE JOURNAL OF PARASITOLOGY 


occur, but much less frequently than in the case of erythrocytes 
infected with Plasmodium vivax, and the dots are smaller and less in 
number. I believe that those who have reported Schuffner’s dots as 
occurring in erythrocytes infected with the quartan plasmodium 
(Plasmodium malariae) have really been observing the variety minuta 
of Plasmodiwm vivax, for it is with the quartan plasmodium that this 
plasmodium is most apt to be confused. Indeed, the resemblance of 
this variety of the tertian plasmodium to the quartan, so far as mor- 
phology goes, is much greater than it is to the tertian plasmodium, but 
the fact that the parasite is found only in cases having a tertian 
periodicity, together with the character of the pigment and its arrange- 
ment, definitely separates it from Plasmodium malariae, and demon- 
strates that it is closely related to the tertian plasmodium. In the 
stained preparations the fine pigment, the characteristic arrangement 
of the chromatin and the absence of “band forms” serve to distinguish 
this variety of Plasmodium vivax from Plasmodium malariae, but 
unless one is well acquainted with the morphology of the latter plas- 
modium this variety of the tertian parasite will almost certainly be 
confused with it. 

The occurrence of all stages of development in the peripheral blood 
is sufficient to differentiate this plasmodium from either Plasmodium 
faiciparum or Plasmodium falciparum quotidianum, while the large 
size of the organism and its general morphology definitely proves that 
it does not belong to either of these species. 

From my own observations, which are confirmed by those of Emin, 
I believe that this plasmodium should be considered a variety of Plas- 
modium vivax, and that it should be known by the name given it by 
Emin, that is, Plasmodium vivax variety minuta. I do not believe that 
the evidence is sufficient to prove that it is entitled to specific rank. 


PLASMODIUM TENUE 


In two identical contributions published separately, Stephens 
(1914, 1914a) describes what he considers a new species of malaria 
plasmodium. This so-called species is described from the parasites 
observed in a single blood-slide sent Stephens by Major Kenrick, 
I.M.S., from Pachmari, Central Provinces, India. Both of the contri- 
butions are illustrated with the same drawings and demonstrate con- 
clusively that the plasmodia present in this slide are all in practically 
the same stage of development, so that the species is described from 
only one stage of development, and that an early stage, before the 
development of pigment. This parasite Stephens has named Plas- 
modium tenue, and he states that he believes that it has affinities with 
the simple tertian plasmodium and with Plasmodium canis of the dog, 
rather than with the malignant tertian parasite. 


CRAIG—NEW MALARIA PLASMODIA 91 


Basing his deductions entirely on the stained preparation, Stephens 
considers the distinguishing features of this species to be extreme 
ameboid activity, scanty cytoplasm, and an amount of nuclear chro- 
matin out of proportion to the volume of the parasite. The extreme 
ameboid activity is evidenced by the marked variations in the shape 
of the parasite, ring forms being rare, while the vast majority of the 
organisms present long, thin processes stretching across the infected 
erythrocyte, frequently multiple in number. The small amount of 
cytoplasm is contained within these filamentous processes. The nuclear 
chromatin appears out of proportion to the volume of the plasmodium, 
occurring in the form of rods, strands, forked masses, patches, etc. 
The chromatin is situated in the protoplasmic processes either as 
strands, rods or angular masses situated at the junction of the two 
processes. Stephens says: “Abundance of and marked irregularity in 
the distribution of the chromatin masses are characteristic of this 
parasite.” 

Stephens considers that this plasmodium differs from the malig- 
nant tertian plasmodium (Plasmodium falciparum) in possessing 
greater ameboid activity and in the abundance and irregularity of the 
nuclear chromatin, and from the simple tertian plasmodium (Plas- 
modium vivax) in being smaller, having more delicate ameboid proc- 
esses, a larger. amount of and more marked irregularity in the distri- 
bution of the chromatin, and in the rarity of typical “ring’’ forms. 

From the description of this organism given by Stephens and the 
drawings which accompany the description, it is, to say the least, 
extremely doubtful if this parasite can be accepted as a new species 
of malaria plasmodium. Even though it differed from the known 
species to a much greater extent than 1s described, it would be entirely 
unjustifiable to describe it as a new species from the morphology of 
the parasite during only a small portion of the life cycle and from 
the organisms observed in a single stained blood-smear. The mor- 
phological details on which the species is based are inadequate to 
establish the species, especially as the plasmodium is undoubtedly in 
that stage of development, the young unpigmented stage, in which a 
differential diagnosis from Plasmodium vivax would be most difficult. 
As a matter of fact, Stephens states that he is in doubt as to whether 
Schuffner’s dots occur in the infected erythrocyte, but admits finding 
one infected erythrocyte which was enlarged and showed Schuffner’s 
dots. Regarding the morphology of the plasmodium observed in this 
erythrocyte, Stephens says: “Although I could detect no pigment in 
this parasite I was not otherwise able to distinguish it from a simple 
tertian parasite.” 


92 THE JOVRNAL ~ OF PARASITOLOGY 


Admitting, as I believe nearly every protozoologist will, who has 
had an extensive experience with the plasmodia of human malaria, 
that the classification of this organism as a new species is not justified, 
owing to the fact that practically only one stage of development has 
been observed and that the morphological characteristics are not suffi- 
cient to base a species on, the question remains as to the exact position 
of this plasmodium which appears to possess some peculiarities not 
usually described for the well-known species of human plasmodia. 
From my own experience, I am convinced that all of the species of 
malaria plasmodia present at times, and from unknown or known 
causes, atypical generations, so far as morphology are concerned, and 
if specimens of blood containing such plasmodia be studied to the 
exclusion of others from the same infection, one is most apt to regard 
these plasmodia as varieties or new species. Time and again I have 
been on the point of describing such atypical plasmodia as new species 
and have only hesitated because of previous experience with similar 
forms. In many of the patients showing these atypical plasmodia 
continued observation has demonstrated that the atypical forms were 
replaced by typical examples of one of the well-known species, while 
in other instances a minute examination of the preparations would 
show that, while the atypical plasmodia were the most numerous, typ- 
ical parasites of one of the recognized species did occur, though per- 
haps in very small numbers. 

As regards the parasite described by Stephens as Plasmodium 
tenue, | may say that I have several times encountered exactly similar 
parasites, so far as I can determine from his description and drawings, 
in undoubted infections with Plasmodium vivax, and for this reason I 
believe that Stephens’ plasmodium is a rather atypical form of Plas- 
modium vivax in the unpigmented stage of development. As claimed 
by Stephens, the evidence of ameboid activity is pronounced, but no 
more so than is frequently observed in preparations of blood containing 
Plasmodium vivax at a corresponding stage of development, while the 
extreme delicacy of the cytoplasmic pseudopodia is frequently observed 
in tertian infections in which quinin has been administered in insufh- 
cient dosage to kill the plasmodia, but sufficient to produce a stimula- 
tion of ameboid activity and consequently a greater number of cyto- 
plasmic processes. The amount of chromatin present in Stephens’ 
plasmodium is greater than is usually observed at this stage of devel- 
opment, but not greater than | have observed in plasmodia in undoubted 
infections with Plasmodium vivax, in which the parasites were in the 
same stage of development. At this stage of development the infected 
erythrocyte is very frequently not enlarged in infections with the ordi- 
nary tertian plasmodium, so that the lack of enlargement of the eryth- 


CRAIG—NEW MALARIA PLASMODIA 93 


rocyte is not a point in favor of a new species. As a matter of fact, 
the distortion in the shape of many of the infected erythrocytes, as 
shown in Stephens’ drawings, is very characteristic of tertian infec- 
tions, and the fact that the erythrocyte containing the single organism 
observed in a later stage of development (an organism which Stephens 
states he was unable to distinguish from Plasmodium vivax except for 
the absence of pigment) was enlarged and presented Schuffner’s dots, 
is certainly good evidence that this parasite is a more or less atypical 
form of the ordinary tertian plasmodium, or Plasmodium vivax. 

The reasons underlying the production of morphologically atypical 
generations of malaria plasmodia are obscure, but I am convinced that 
insufficient dosage with quinin, and perhaps with other drugs, often 
leads to the production of such plasmodia and that these plasmodia 
may retain for several generations morphological abnormalities pro- 
duced by adverse agencies, either physical or chemical. We know 
that in the case of Entamoeba histolytica the character of the nucleus 
is absolutely changed by the administration of drugs that produce a 
cessation of the acute symptoms of dysentery, and there is no reason 
why the same should not occur in the instance of the malaria plas- 
modia. So marked are the changes produced in the morphology of 
Entamoeba histolytica by either chemical or physical conditions leading 
to the cessation of acute symptoms that the form of the parasite occur- 
ring when the dysenteric symptoms abate was long regarded by the 
best protozoologists as a distinct species of entameba, and I believe 
that it is only reasonable to admit that the same influences may cause 
atypical generations of the malaria plasmodia. 

In proof of this assertion I may state that I have followed infec- 
tions in which the plasmodia were very atypical, being modified mor- 
phologically by the exhibition of small doses of quinin, and have seen 
a return to normal morphology when the drug was discontinued. One 
of the most common effects of quinin is a great stimulation in the 
ameboid activity of the malaria plasmodia and an apparent stimula- 
tion in the division of the chromatin, as evidenced by the presence of 
delicate pseudopodia containing an abnormal amount of chromatin 
during the early stages of development of the plasmodia. I would 
not wish to be understood as claiming that this is the explanation of 
the morphology of the parasite discussed in this instance, but I am 
satisfied that Plasmodium tenue is an atypical form of Plasmodium 
vivax. I have observed identical forms, so far as can be judged from 
the description and drawings, not once, but a considerable number of 
times, in supposedly untreated infections with Plasmodium vivax, and 
many times in infections with this plasmodium after the exhibition of 
doses of quinin insufficient to kill the plasmodia. 


94 THE SOURNAL OF PARASTTOLOGY 


However, whether or not this parasite is identical with Plasmodium 
vivax, it cannot be accepted as a new species until the morphology of 
the parasites during the entire human life cycle at least is studied, for 
the only claim it now has to specific rank is the presence of slight dif- 
ferences in morphology during a very limited portion of the human 
life cycle, that is, the early unpigmented stages of development when 
such differences are commonly observed even in the well-recognized 


species of plasmodia. 
REFERENCES CITED 


Craig, C. F. 1900. Report Bacteriological Laboratory, U. S. Army General 
Hospital, Presidio of San Francisco, Cal., for 1899 and 1900. Surgeon-General’s 
Report, U. S. Army, p. 59. 

1901. The Estivo-Autumnal (Remittent) Malarial Fevers. New York. 

1909. The Malarial Fevers, Hemoglobinuric Fever and the Blood Protozoa 
of Man. New York. 

1909a. The Classification of the Malarial Plasmodia. Boston Med. and 
Surg. Jour., 160: 677. 

Doflein. 1911. Lehrbuch der Protozoenkunde. Third Ed. Jena, p. 770. 

Emin, Ahmed. 1914. Une variete nouvelle de parasite de Laveran. Bull. 
fal lls Syores IEGilns Ibsen, 72 Stee 

Grassi and Feletti. 1890. Ueber die Parasiten der Malaria. Centralbl. f. 
Bakteriol., etc., 7: 396-430. 

Lithe, M. 1900. Ergebnisse der neueren Sporozoenforschung. Jena. 

Mannaberg. 1899. Die Malaria Krankheiten. Nothnagel’s Encyclopaedia der 
Medicin, Berlin. 

Marchiafava and Bignami. 1894. Estivo-Autumnal Malaria. The New 
Sydenham Society, London, vol. 150. 1892. Ueber die Varietaten der Malaria- 
parasiten. Deutsch. med. Wehnschr., 51: 1157-1188. 

Sacharoff. 1896. Ueber den Entstehungsmodus der verschiedenen Varietaten 
der Malariaparasiten. Centralbl. f. Bakteriol., etc., 19: 268. 

Schaudinn, Fr. 1902. Studien tuber krankheitserregende Protozoen. II. 
Plasmodium vivax, etc. Arb. a. d. Kaiserl. Gesundheitsamte, 19: 169. 

Stephens, J. W. W. 1914. A New Malaria Parasite of Man. Proc. Royal 
Soc., Series B 87, p. 375. 

1914a. A New Malaria Parasite of Man. Ann. Trop. Med. and Parasit. 
Series T. M., 8: 119. 


THE POISON GLANDS OF THE LARVA OF THE BROWN- 
TAIL, More 


(EUPROCTIS CHRYSORRHOEA LINN.) 
CORNELIA F. KEPHART 


It is well known that certain lepidopterous larvae possess urticating 
hairs which are the cause of a more or less severe and painful irrita- 
tion when they come in contact with the human skin. In this country, 
the one which has attracted the most general attention on. this account 
is the larva of the imported brown-tail moth, Euproctis chrysorrhoea. 
A great many cases of poisoning have been attributed to this species, 
and one death has been reported as the result of severe internal poison- 
ing caused by inhaling the hairs. 

There has been much discussion among scientists as to whether the 
effect of these hairs is purely mechanical or whether they are actually 
poisonous, but on the other hand, singularly little definite study has 
been made of the morphology of the hairs and their underlying struc- 
tures. It was for this reason that the subject of this paper was sug- 
gested by Dr. W. A. Riley and to him the writer is greatly indebted 
for much kindly criticism and many helpful suggestions. 

In 1894 Packard described the poisonous spines of Lagoa crispata, 
stating that the spines themselves were secreted by certain large tri- 
chogen cells lying under the rest of the hypodermis and connected with 
the spines through pore canals in the cuticle. In addition to these cells 
there were other smaller ones lying in different places above and below 
the hypodermis, and even in the pore canal itself, which he called 
“poison nuclei,’ and which he claims secrete the poison. Ingenitsky 
(1897) studied several different forms, especially Ochneria monacha 
Linn., and he clearly demonstrated that there are two cells connected 
with each hair and that the smaller of the two is the trichogen cell, 
which, after secreting the hair, decreases in size, and that the large cell 
is the actively secreting poison gland. Aside from the fact that 
Ingenitsky carefully traced the development of the two cells through 
all stages of the larva, this view would seem to be the reasonable one, 
because one would naturally expect to find that the actively secreting 
cell was larger than one that had already stopped its action. This 
latter is the same view as that expressed by Holmgren (1895). He 
also found that the poison hairs were connected with two cells, one 
somewhat larger than the other, one of which secreted the hair and the 
other the poison. 


96 THE SOURNAL OFGPARAS!TOLOGY 


In all the forms studied by the different authors, however, the 
hairs were one of two general types. The first is a simple hair taper- 
ing from the base to the tip and containing a poisonous substance, the 
exact nature of which is not known. When one of these hairs comes 
in contact with the skin the point breaks off and the contents are 
liberated in the blood. 

The second type is practically the same except that the tip of the 
hair is in the form of a more heavily chitinized cone which is fitted, 
cap-like, on the end of the hair and which is readily detachable. In 
this instance the hair remains on the larva, the tip only breaking off 
and entering the skin. This type occurs most frequently on the 
so-called slug caterpillars. These hairs are also said to contain poison, 
although there has been no evidence brought forward so far to prove 
that their action is anything more than that of a mechanical irritant. 


Fig. 1—Hairs of a larva of Euproctis chrysorrhoea. A. Ordinary hairs. 
MS: Bs boisonmaainssmexe 300! 


The poison hairs of the brown-tail caterpillar are of a very different 
tvpe (Fig. 1, B). They are pointed at the base, gradually enlarge 
toward the tip and have three rows of barbs extending their entire 
length. They are heavily chitinized, and are filled with a granular 
substance similar in appearance to the contents of the underlying 
hypodermal cells. These hairs are found only on the subdorsal and 
lateral tubercles (Fig. 2, sdt and /t), arising in bunches of from three 
to twelve on minute papillae with which the tubercles are thickly 
covered (Fig. 3, pap). Tyzzer (1907) claims to have found as many as 
twenty on a single papilla, but the writer has not found more than 
twelve, five to seven being the usual number. They are 70 microns to 
100 microns in length and 4 microns to 5 microns in thickness at the 
larger extremity. 


KEPHART—POISON GLANDS OF BROWN-TAIL 97 


There has been considerable doubt in the minds of many entomol- 
ogists as to whether the hairs were really poisonous or whether they 
acted merely as mechanical irritants, but the experiments of Dr. E. E. 
Tyzzer seem to indicate that there is some specific poison in the hairs. 

He found that if one of the netthie hairs be introduced into a 
drop of blood a peculiar change takes place in the red blood-corpuscles. 
To quote from his report: “They at once become coarsely crenated, and 
the rouleaux are broken down in the vicinity of the hair. The cor- 
puscles decrease in size, the coarse crenations are transformed into 
slender spines which rapidly disappear, leaving the corpuscles in the 
form of spheres, the light refraction of which contrasts them strongly 
with the normal corpuscles. The reaction always begins at the basal 
sharp point of the hair. Minute particles of glass wool, the barbed 


Fig. 2—Cross section of a larva of Euproctis chrysorrhoea showing distri- 
bution of poison hairs; sdt, sub-dorsal tubercle; /t, lateral tubercle; cut, cuticle ; 
hyp, hypodermis. 


hairs of a tussock moth, and the other coarser hairs of the brown-tail, 
all failed to produce any effect on the red blood-corpuscles.” These 
experiments I have repeated with the same results. 

Dr. Tyzzer then tried the effect of heating on the activity of the 
hairs and found that after baking them for an hour at 110 C. they still 
gave a typical reaction with the red blood-corpuscles and produced the 
typical dermatitis when rubbed on the skin. But he found that after 
baking for an hour at 115 C. they failed to react on the corpuscles, 
and when rubbed on the skin produced only a slight redness and irri- 
tation, such as is caused by any foreign body penetrating the epidermis. 
All these facts seem to show that there is a definite poisonous substance 
either in or on the hairs. 

He next tried a number of reagents to determine the solubility of 
the irritating substance. He found that acetone, alcohol, chloroform 


98 THE SJOURNAL ‘OPS PARASTTOLOGY 


and ether had no effect on the reaction of the hairs, whether they were 
boiled in it or left for days at room temperature. I have found, how- 
ever, that the hairs from caterpillars that had been kept for five weeks 
in 70 per cent. alcohol failed to kave any effect on the red blood- 
corpuscles, while those from the cast skins of larvae which had been 
kept in a dry place for several months produced the characteristic 
reaction when introduced into a drop of blood. “The nettling hairs 
remain active after being boiled in pyridin, which boils at a tempera- 
ture between 106 and 108 C. They also remained active when kept 
for several days in glacial acetic acid, in 0.5 per cent. acetic and in 
both 1 per cent. and 0.1 per cent. HCl.” But when they were left over 
night in 1 per cent. and 0.1 per cent. solutions of KOH and NaOH 
they failed to react either on the skin or on the red blood-corpuscles. 


=—— 
——-= 
——-s 
=o 


—— 


Fig. 3.—Enlarged section of a tubercle; oh, ordinary branched hair; ¢r, 
trichogen cell; ph, poison hair, can, pore canal; pap, papilla; pc, poison-secret- 
ing cell; hc, hair formative cell; cut, cuticle; hyp, hypodermis. Studied under 
low power, arrangement of cells semidiagrammatic. 


This difference in the action of the weak acids and the weak alkalies is 
not surprising, since the blood fluid is itself alkaline and the poison is 
soluble in it. 

The next question which arises is whether the poisonous substance 
is contained in the hair or is merely smeared on the outside, as a 
number of writers suggest. 

If it is on the inside there must be a pore, or opening, of some 
kind in the point of the hair, because, as has already been stated, the 
reaction of the red blood-corpuscles always begins around the basal 
point of the hair and gradually spreads from there, except in the 
instances where the hair has been broken, when the action takes place 
rapidly around the point of fracture. In the poison hairs of certain 
other forms, a tiny opening in the point of the hair is distinctly visible, 


KEPHART—POISON GLANDS OF BROWN-TAIL se) 


but it has been impossible so far to detect any such pore in the poison 
hairs of the brown-tail caterpillar even with an oil emersion lens. 

If the substance is merely smeared on the outside, however, what 
is its source and how does it reach the hair? If, as some writers sug- 
gest, it is secreted in the two red tubercles on the caudal end of the 
body, then the long hairs as well as the short ones would be covered 
with it. This has not proved to be the case. Furthermore, Dr. Tyzzer 
found that if a hair be dried and then placed in some such stain as 
Loeffler’s alkaline methylene-blue solution, the dye first penetrated the 
point of the hair and then gradually diffused throughout its entire 
length. These observations strongly indicate that there is a pore in 
the point of the hair, but there is one thing that Dr. Tyzzer seems to 


Fig. 4—Diagram of arrangement of hairs and cells; pl, poison hair; pap, 
papilla; cut, cuticle; str, prolongation of hair formative cell; thr, threads of 
poison; pc, poison-secreting cell; muc, nucleus of poison secreting cell; fc, hair 
formative cell; bw, basement membrane. 


have overlooked. As he says, the nettling hairs occur in groups inserted 
point first in protuberant rounded sockets or papillae on the subdorsal 
and lateral tubercles. These papillae are set very close together, 
although not actually in contact with each other. 

Now the hairs of insects are formed simply by the outpushings of 
certain hypodermal cells, which, projecting above the general level, 
secrete their cuticle in the form of hair-like prolongations of chitin. 
The projecting hairs would therefore be hollow and their contents con- 
nected directly with the contents of the underlying cell. Then, since 
the hairs under consideration are inserted point first, this connection 
must be through the point, and this would leave a pore, or opening, 
through which the poison may diffuse into the blood when the hair is 
detached. 


100 THE JOURNAL OF PARASITOLOGY 


The hypodermis of the subdorsal and lateral tubercles is very 
different in appearance from that of the other regions of the body, 
being much thicker. This increase in thickness is due to the great 
length of the cells which lie directly beneath the poison hairs. They 
are all much elongated, three or four times the length of the ordinary 
hypodermal cells, and are closely crowded together. The connection 
between the cells and the poison hairs is effected through pore canals 
in the cuticle the same as with the ordinary hairs, the only difference 
being that instead of there being a pore canal for each hair there is 
one for each papilla on the tubercle, all the hairs on a papilla being 
reached through the same pore canal (Figs. 3 and 4). 

The cells are divided into two groups, one composed of large cells 
3.3 microns in diameter, the other composed of smaller ones 1.95 
microns to 2.02 microns in diameter. The cells of the first group lie 
directly under the cuticle (Fig. 3, pc) and have crowded out the smaller 
cells toward the basement membrane, which gives a two-rowed appear- 
ance to the hypodermis. These large cells, one of which lies directly 
under each of the hair-bearing papillae, are composed of granular 
cytoplasm, corresponding in appearance with that of the ordinary 
hypodermal cells, with large nuclei which, however, are smaller in pro- 
portion to the size of the cell than those of the other group (Fig. 4, 
nuc). In the cytoplasm there are fine threads of a darkly staining 
substance which converge toward the apex of the cell and unite into a 
coarser thread which passes through the pore canal in the cuticle and 
enters the papilla. There it divides again, one thread going to each of 
the hairs on the papilla (Fig. 4, ph). 

At first sight these cells bear a slight resemblance to nerve cells 
with nerve fibers running out from them; but they are rather the 
poison-secreting cells and the threads, coagulated secretion connected 
with the individual hairs. This would seem to be the case for three 
reasons: In the first place, there are no other cells remotely resembling 
these in any part of the body; this fact in itself being enough to pre- 
clude the possibility of their being nerve cells. In the second place, 
suppose that they were really nerve cells and the hairs instead of being 
poisonous were merely sensory. What would be the object of having 
sense organs so loosely attached to the body of the insect that the 
slightest touch suffices to dislodge them? And what could be their use? 
Obviously, they could not be tactile, because they are so very short 
that practically nothing could get to them through the long hairs with 
which the body is thickly covered. It would take something more 
stable to serve the purposes of hearing and as for the chemical senses, 
taste and smell, they are so absolutely different from any other organs 
of that nature that such a supposition would be unlikely on the face 


KEPHART—POISON GLANDS OF BROWN-TAIL 101 


of it. If sensory, they would seem to be of some sense with which we 
are unfamiliar and one peculiar to this particular species of caterpillar, 
especially fitting it for its mode of life. Since its habits are not mark- 
edly different from those of a great many of our social caterpillars, 
the writer is at a loss to account for the necessity of such a highly 
specialized sense. 

Then, since they are evidently not nerve cells, and since they are 
actively secreting, it would seem legitimate to assume that they are 
poison cells. The hairs themselves are formed by the smaller cells, as 
will be shown later, the papillae are merely cuticular appendages and 
there is nothing else present for which active gland cells could possibly 
be used. 

The cells composing the second group are of a very different 
appearance from those just described. They are much smaller; meas- 
uring from 1.95 microns to 2.02 microns in diameter. They are fusi- 
form in shape, irregularly arranged, and appear as though crowded out 
of their regular position by those around them. There is compara- 
tively little cytoplasm and it does not contain the threads of poisonous 
substance (Figs. 3 and 4, hc). These cells correspond in number with 
the hairs and each cell is connected by means of a strand of cytoplasm 
with a hair. The strands of cytoplasm are in fact nothing more nor 
less than portions of the cells which extend up around and between 
the poison cells ( Fig. 4, str), through the pore canal and papilla directly 
to the hairs. In other words, the smaller cells are the hair formative 
cells for this particular kind of a hair. 

The basement membrane extends along beneath the second group 
of cells and is very easily detected, much more so in fact than in the 
other parts of the body wall; and all the cells, whether poison-secreting 
or hair formative, are connected with it either lying directly on it or 
connected by means of fine threads of the cell substance. 

Beille (1896) described something very similar to this as obtaining 
in one of the processionary caterpillars, Cnethocampa pityocampa 
Borowski. In that species the surfaces of the tubercles bearing the 
urticating hairs are divided into four areas by two bands which cross 
the tubercle at right angles to each other and which are free from hairs. 
The four sectors thus made are covered with chitinous papillae which 
bear the poison hairs and which are connected with the subjacent parts 
by pore canals in the cuticle in the same way as those of the brown-tail. 
“The glandular part exists only under the sectors covered with hairs. 
These glands are separated from each other by connective-tissue 
strands and a membrane of the same nature separates them from the 
subjacent organs. These glands are unicellular and are in the form of 
very elongate pears. . . . In the narrower parts one sees a canal 


102 THE JOURNAL  OFRPARASITOLOGY 


which is continuous with each of those which cross the chitinous area. 
These glands are therefore analogous in their structure to those which 
correspond to the large hairs, and ought to be considered as hypo- 
dermal glands.” 

Unfortunately, there are no illustrations in his paper, and it is 
somewhat difficult to interpret his descriptions. He says nothing to 
prove the glandular nature of these cells, and the probability is that 
some of those that he describes are the hair-formative cells. Judging 
from the brown-tail, his connective tissue strands are the prolonged 
distal portions of the hair formative cells. However, that a condition 
exists similar to that found in the brown-tail seems probable and it is 
quite probable that further work done on the larvae of the proces- 
sionary caterpillars will bring out still further evidences of the simil- 
arity of their structures. 

Probably the nearest approach to the structures found in the 
brown-tail are those recently described by Eltringham (1914) as occur- 
ring in the closely related species Porthesia (Euproctis) similis Fuess. 
He says that these hairs are connected with two rows of hypodermal 
cells similar to the one row in Figure 3, which cells, he thinks, doubt- 
less secrete the hairs. If two rows of hypodermal cells do exist in this 
form it is an aberrant condition, and from Eltringham’s description 
and figures it seems probable that what he took for a second row of 
cells was either an invagination of the body wall, a portion of the 
hypodermis from some other part of the body which had become dis- 
placed in the process of sectioning, or else some other tissue entirely. 

There are also figured some very peculiar looking structures which 
he calls the “plume-like structures.” These are said to occur among 
the urticating hairs and to “arise from a chitinous socket, differing 
little, if at all, from the sockets of the larger branched hairs, and 
having at its base several cells apparently of a glandular nature.” 
These “plume-like structures” correspond in position to some of the 
large branched hairs of the brown-tail and it is possible that what 
Eltringham took for a single structure is really a group of branched 
hairs, each hair being connected with one of the cells at the base of 
the structures. 

More work will have to be done on all the poisonous forms before 
generalizations can be made, but, taking all things into consideration, 
it is clear that the short barbed hairs occurring on the subdorsal and 
lateral tubercles of Euproctis chrysorrhoea contain a definite poisonous 
substance and do not act merely as mechanical irritants; and it is 
probable that a similar condition of affairs exists in a number of 
different species. 


KEPHART—POISON GLANDS OF BROWN-TAIL 103 


SUMMARY 


1. Tyzzer’s statement that a definite poisonous principle is con- 
tained in the short barbed hairs of the larva of the Brown-tail Moth is 
confirmed. 


2. This substance is secreted by certain specialized hypodermal 
cells and is liberated in the blood through the sharp basal point of the 
hairs when they come in contact with the human skin. 


3. The poison glands are larger and fewer in number than the cells 
which form the hairs, there being one poison cell for each papilla on 
the tubercle instead of one for each hair. 


REFERENCES CITED 


Beille, M. L. 1896. Etude anatomique de l’appareil urticant des chenilles 
processionnaires de pin maritime, Cnethocampa pityocampa Borowski. C. R. soc. 
biol., 3: 545. 

Eltringham, H. 1914. On the urticating properties of Porthesia similis 
Fuess. Trans. Ent. Soc., 1913, Pt. 3, p. 423. 

Ingenitsky, I. 1897. Zur Kenntniss der Driisenhaare der Nonneraupe. 
Horae Soc. Ent. Rossicae, 30: 129. 

Packard, A. S. 1894. A study of the transformations and anatomy of 
Lagoa crispata, a Bombycine Moth. Proc. Amer. Phil. Soc., 32: 275. 

Tyzzer, E. E. 1907. The pathology of the browntail moth dermatitis. 
Second Ann. Rpt. Supt. for Suppressing the Gypsy and Browntail Moths, Mass. 


AN APPEAL TO AMERICAN HELMINTHOLOGISTS 


Au. MRAZEK 
Professor of Zoology, Bohemian University, Prague 


Some years ago the muskrat was introduced into Bohemia. This 
animal has not only taken possession of his new home, but soon over- 
spread the whole country and is now continuing his conquering course 
beyond the boundaries of Bohemia in the neighboring lands of Bavaria, 
Saxony, etc.« 

This fact is certainly in zoogeographical respects a very interesting 
one. It offers, so to speak, an academic instance for demonstrating 
some general biological laws concerned in the geographical distribution 
and spreading of animals, an instance that especially for American 
zoologists would be of some interest as relating to a well known repre- 
sentative of the North American mammalian fauna. 

But it is not my intention to dwell here on this point. Nor yet on 
the economic side of the introduction of the muskrat into Bohemia 
which has proved to be most disastrous to pisciculture in our country 
by its destructive action (burrowing in the pond dams, etc.), although 
this side might be also of some interest to the American zoologists 
interested in the economic aspect of the science. The muskrat as a 
fur-bearing animal is of economic importance, and the experiences we 
have had in Bohemia on the possible, incredible rate of increase in 
number of individuals, would perhaps give some hints for protective 
measures in North America. 

I will only call attention to the parasitological side of the muskrat 
problem. It is obvious that a detailed study of the parasitological 
fauna of the muskrat in his new environmental conditions in Bohemia, 
respectively Europe, might throw some light on several general prob- 
lems of parasitology. 

I have myself already commenced this study, but I soon learned 
with regret and to my discomfiture, that the indispensable comparative 
basis for such studies, a knowledge of the parasites of the muskrat in 
his original American home, is lacking. I find this confirmed in a paper 
recently published by an American colleague, Professor Barker (Lin- 
coln, Neb.), who also states that very little is known on the parasites 
of the muskrat. For this reason I beg to draw the attention of Amer- 
ican helminthologists to this point and recommend to them the study 
of the parasites of one of the most typical North American mammals. 

I am sincerely glad that I have the opportunity to publish this 
appeal in the columns of a new American journal devoted to the study 
of parasitology. I greet and welcome this journal and I am sure that — 
it will contribute much to the general progress of parasitology. 


KILLING SMAED ARTHROPODS. WITH THE LEGS 
EXTENDED 


R. A. CooLrey 


Entomologist, Montana Agricultural College, Bozeman. 


Any one who has worked with alcoholic ticks recognizes the dis- 
advantage of the curled position of the legs which is usually assumed 
in such specimens. In connection with experiments in methods of 
preserving female ticks in various stages of engorgement, it was acci- 
dentally learned that flat or unfed females, and all males, are left with 
the legs extended if killed by dropping into boiling water. Specimens 
so treated also become slightly distended, which is often an advantage. 

The ticks are dropped, one at a time, from a height of 6 or 8 inches 
into a small dish of water over a flame. A pair of fine curve-pointed 
forceps is used for picking up and dropping the ticks, and a minute 
‘strainer on a handle is convenient for removing them from the water. 
Specimens which are removed as quickly as possible have the legs 
properly extended, but we have not observed any injury to others 
allowed to remain immersed longer. 

Partly engorged females are improved as specimens if treated in 
this way, but larger females may be overdistended or may be injured 
by a cracking and slipping of the integument. Nymphs killed in this 
manner make better specimens, and it is probable that larvae would 
also be improved, though we have not tried the method on them. 

Assistant Entomologist J. R. Parker has tried this method in killing 
aphids before clearing in turpentine-carbolic acid mixture, and finds 
that the legs are generally extended in symmetrical positions as with 
ticks. In the case of aphids this is apparently due to the legs being 
fixed in the position they have when they touch the water rather than 
to an extending of the legs after immersion. With ticks and aphids at 
least, this method appears to be of great value, and it is probable that 
with many other arthropods its adoption would be beneficial. 

In this connection it may be of interest to state that living, unfed 
ticks may be induced to extend the legs by squeezing them lightly 
between two pieces of glass. In this position they may be photographed 
or examined under a binocular microscope without injuring them. For 
this purpose we have used a thin microscopic slide on one side and a 
seven-eighths by 2-inch cover-glass on the other, the two being held 
together by rubber bands. The cover-glass curves and touches the 
slide at both ends, and the amount of pressure on the tick is governed 
by varying the distance between the two rubber bands. 


SOCIETY PROCEEDINGS 


THE HELMINTHOLOGICAL SOCIETY OF WASHINGTON 


The twenty-first regular meeting of the society was held at the residence 
of Mr. Crawley, Sept. 22, 1914, Mr. Crawley acting as host and Mr. Foster as 
chairman. Dr. R. T. Shields of Nankin, China, was a guest of the Society. 

Mr. Crawley gave a demonstration of a Leitz microscope, designating some 
of the recent improvements. 

Dr. Shields gave a talk on the parasites of man and the domestic animals 
around Nankin. 

Mr. Hall reported a second case of Fasciola magna in the sheep. The fluke 
was found in a liver sent in from Ovando, Mont., where a number of sheep 
had died. These sheep showed black markings of the omentum and abscesses 
of the liver, lungs or spleen. A spleen that was sent in was very much enlarged 
and full of what appeared to be embolic bacterial abscesses. Fasciola magna 
in cattle apparently exerts little influence on the health of infested cattle. It 
is however, rather interesting to note that in this case and in the first case of 
Fasciola magna, reported by Hall in 1912, attention was called to the presence 
of the parasite by the fact that numbers of sheep were dying in each case. 
It seems very likely that Fasciola magna exerts considerable effect on the gen- 
eral health of infected sheep, even causing death in a rather high percentage 
of cases, but this is a matter that needs further investigation. In the previous 
cases the sheep were noted as showing emaciation, edema and _ peritonitis. 

Maurice C. Hatt, Secretary. 


NOTES 


For the purpose of extending the investigations and experimental work 
relative to the parasites of live stock, the Zoological Division of the Bureau 
of Animal Industry has obtained a farm near: Vienna, Va., where a study will 
be made of various problems in the control and eradication of the internal 
parasites of sheep. 

The University of Illinois has begun the publication of a quarterly series 
entitled Illinois Biological Monographs. The first, a double number, is devoted 
to A Revision of the Cestode Family Proteocephalidae by George R. La Rue. 
Extended notice will be given this paper in a later number of the JoURNAL. 


Phe Journal of Parasitology 


Volume 1 MARCH, 1915 Number 3 


SPIDER POISON 


VERNON L. KELLOGG 
Stanford University, Cal. 


The not-infrequent occurrence of the notorious “black widow” 
spider, Latrodectes mactans, in the vicinity of Stanford University, 
has led me to a limited personal attention to the subject of spider 
poison and its effects. For this spider, as is well known, has the 
unsavory reputation of being one of the most poisonous of all spider 
kinds. The matter was given an added interest for me when Dr. E. H. 
Coleman, a young graduate in medicine beginning a practice in the 
village of Los Altos, 5 miles from the university, and registered with 
me as a graduate student, reported a personal knowledge of two cases 
of the biting of human beings by Latrodectes, both of the cases result- 
ing in an immediate serious condition of the patients. Dr. Coleman, 
in his turn, became much interested in the spider and its poison and 
besides noting and recording very carefully the effects of the poison on 
his patients, was led to the preparation of a much-diluted extract of 
the poison, with which he experimented on cats and rabbits and even 
on himself with no uncertain results, and later, under very ae 
circumstances, on a patient suffering from angina pectoris. 

The genus Latrodectes contains several species which are scattered 
widely over the world. A species (L. malmigniatus) of South Europe, 
is familiarly known and feared under the common name of “la malmig- 
niatte’’ and another species of New Zealand is called “Katipo” by the 
natives, and is also much feared. In the two American continents 
three species occur, of which the most widely distributed and abundant 
one is Latrodectes mactans, which has a range from the northern 
boundary of the United States to Tierra del Fuego. It is a common 
spider in our Southern and Southwestern states. Of the other two 
American species, one (L. curacaviensis) is recorded only from the 
West Indies and the eastern countries of South America, while the 
other (L. germetricus) is called by Petrunkewitsch a tropical species, 
but Comstock states that it has been taken in California. It certainly 
is not familiar here. 


108 THE JOURNAL. OF PARASTT OLOGY 


All the species agree in general appearance and size, the female, 
which is much larger than the male and with nearly spherical abdomen, 
while the male has a more elliptical abdomen, being about 12 mm. in 
length and sooty-black or dark brown in color, with a conspicuous 
small blotch or blotches of vivid red on the under side of the abdomen. 
This blotch or pair of fusing blotches has the rough outline of an hour- 
glass. However, it varies much in shape. The position of the spot 
and its vivid color contrasting with the sooty background are its dis- 
tinguishing characters. 

The species of Latrodectes seem to be feared wherever they occur. 
Comstock quotes Cambridge as referring to them as “those very inter- 
esting spiders which, under various local names, have been notorious 
in all ages and in all regions of the world where they occur on account 
of the reputed deadly nature of their bite.’ But to this Comstock says: 
“It may be added that this belief is not shared by students of spiders, 
and has probably been suggested by the strongly contrasting colors of 
the more common species which make them appear venomous to the 
credulous observers.” To this I may in turn add that at least one 
student of spiders, though incomparably less experienced than Com- 
stock, does share the belief in the unusually poisonous nature of 
Latrodectes mactans. This belief is based chiefly on the notes of Dr. 
Coleman, which are printed herewith. 

But there are other printed records of presumable trouble from 
Latrodectes bites, and still other records which have been given me 
verbally from a few sources here in California, that bolster up this 
belief. The best known printed records of the effects of presumable 
Latrodectes bites in this country are those published in 1889 in Insect 
Life (vol. I, pp. 204-211, and 280-282). 

Dr. Coleman’s notes of the effects of Latrodectes poison on a 
patient, on himself and on cats and rabbits are, in his own words, as 
follows: 

EFFECTS ON A BITTEN PATIENT 


Patient B. came to my office one morning at 8:15 o’clock, showing signs of 
an acute poisoning of some sort. 

The glans of the penis had been bitten by a spider while the patient was 
sitting in an outcloset. The only thing felt was a sharp sting. (The spider 
was captured so there is no doubt as to the species; it was a female of Latro- 
dectes mactans.) In about ten minutes there appeared dizziness and weakness 
of the legs, followed by cramps in the abdominal muscles. 

The patient left the field where working and started to walk to town, a dis- 
tance of a little over a mile. The pains grew worse and the penis started to 
swell and turn red. When the office was reached, the pains, of a cramp-like 
character, in the abdomen, were intense, also around the heart and thighs. 
Physical examination showed the heart to be running at the rate of 40 per 
minute, of small volume but regular. The respiration was labored. The pupils 
were dilated and face very red and congested. The penis was swollen to a 
great size, fully 3 inches in diameter at the glans, and the color was a mottled 


KELLOGG—SPIDER POISON 109 


purple. The contractions were clonic in character, giving the greatest pain in 
the chest and abdomen. There were no pains below the knees or elbows. 

The treatment consisted of hypodermic injections of strychnin 1/40, followed 
in ten minutes by nitroglycerin 1/100. Local applications to the side of bite of 
the crystals of potassium permanganate. The heart went to as low as 27 beats 
to the minute. After three hours’ work, using repeated injections of strychnin, 
the heart-rate was increased to 45. The pains were not quite so severe and 
the patient was taken home. The administration of strychnin was stopped 
and the use of brandy hypodermatically was substituted, a dose of 10 mm. being 
given every hour. Heat was applied to the feet and back. At 5 p. m, or 
about nine and one-half hours after the first symptoms, the heart-rate had been 
raised to 55 and then as the pains were still severe, a 1% morphin with 1/150 
atropin was given. The pains eased up and the patient dropped to sleep. 

The next morning a fine rash appeared all over the body, accompanied by 
some itching. The penis had returned to nearly normal in size. The heart- 
rate was 60, the respiration 18 and deep, temperature 100. The rash disappeared 
in four days. The patient was troubled with insomnia for several days, and a 
stubborn constipation that took a very active purge to affect. 

Three years have elapsed and the patient has a heart-rate of about 64. No 
» history of what it was before poisoning. Troubled with attack of insomnia 
and a marked bulimia. 


EFFECTS OF THE EXTRACTED POISON ON THE EXPERIMENTER 


The poison glands of a female Latrodectes were dissected out. The sac 
contained a very small drop of liquid of a white viscid character. The sac 
and contents were macerated in 10 drops distilled water, called solution No. 1, 
for several minutes. To this was added 100 grains of pure sugar of milk 
‘and the mass triturated for fully ten minutes. This was labeled No. 2. Ten 
grains of No. 2 was added to 90 grains of fresh milk sugar and triturated, 
making No. 3. Tests were made with trituration No. 3 or a 1/1,000 gr. of 
the poison in each grain; and also No. 2 with practically the same results, 
except that No. 2 was vastly stronger than No. 3. 

Using No. 3, I made powders containing 2 grains each and took one pow- 
der every hour for ten doses, or 0.002 grain poison per dose. (My condition 
before starting test was pulse 72, respiration 18, temperature 98, bowels regu- 
lar daily and no pains or aches.) At the end of ten hours no change could 
be felt, other than a decrease in heart action to 64. No powders were taken 
from 8 p. m. until 7 a. m. the second day. When 15 powders were taken, the 
heart action was 60, and a slight dull occipital headache. The bowels did 
not move at their regular hour in the morning. When 20 powders were taken, 
the heart-rate was 54, the occipital pain was quite severe, cramping pains were 
extending from the chest to the abdominal muscles, the pupils slightly dilated, 
and some distress about the heart. Again no powders were taken during the 
night; but I was very restless and could not sleep. Continued the powders 
on the third day and stopped when the twenty-fifth had been taken. The heart- 
rate was 48, temperature 99, very severe headache, clonic spasms of the thoracic 
or abdominal muscles, marked distress about the heart with radiating pains 
extending to the left arm-pit and down to the elbow; had no bowel action for 
two days; pupils markedly dilated. It seemed a perfect picture of angina pec- 
toris. The symptoms gradually subsided and in three days felt normal. I 
allowed a period of two weeks to intervene and repeated the experiment with 
the same symptom-complex picture. The trial was repeated a third time, with 
always the same results, as to occipital headache, constipation and clonic spasm 
of the muscles of chest and abdomen; also the pain and distress about the heart. 
I was unable to persuade any of my friends to try out the drug, so am limited 
to my own symptoms for a drug picture in the human species. 


110 THE JOURNAL OF PARASITOLOGY 


EFFECTS OF THE EXTRACTED POISON ON RABBITS, CATS AND DOGS 


Several experiments were tried on rabbits and cats with very interesting 
results. 

1. The dissected glands of one female Latrodectes containing the virus. The 
virus was macerated in 10 drops distilled water. The same was injected sub- 
cutaneously into the abdomen of a cat about 8 months old. In about five min- 
utes a series of convulsions set in of a clonic type, quickly followed by a tonic 
spasm and in ten minutes the animal was dead. 

2. A pair of glands were macerated in 10 gtts. of water and diluted to 
100 cc. Ten gtts. of this dilution were injected into the abdomen of an 
8-months-old cat and there resulted in five minutes dilatation of the pupils, 
unsteady gait, drooling of saliva, followed by a series of clonic spasms. The 
heart-rate lowered markedly and the abdomen swelled up to a large size. The 
feces and urine were passed involuntarily. Death occurred in forty-five min- 
utes after injection. 

3. A quantity of the eggs of the Latrodectes was macerated in 20 gtts. 
of water and diluted up to 10 c.c. The injection of this solution produced the 
same typical symptoms and death to a cat 8 months old in about three minutes. 
A rabbit was killed in about two and one-half minutes. 

Ten c.c. of the same solution was injected into a dog about 2 years old and 
weighing 35 pounds, but there was no marked effects, except a lowering of 
the heart-rate; no death or convulsions. This experiment was not repeated. 


EFFECTS OF THE EXTRACTED POISON ON A CASE OF ANGINA PECTORIS 

The most interesting test of the poison was on a man 54 years of age, Mr. 
E., who had been troubled with pain and distress about the heart; pains that 
were of a constricting nature and which radiated to the arms. _A good case 
of angina pectoris. A rigid position when the spell was on, clutching at any 
support, dilatation of the pupils and slow heart action. This patient had had 
several of these attacks, which continued intermittently for about one-half hour 
at each seizure. During one attack I gave one 2-grain powder of the No. 3 
trituration or one hundredth dilution and in ten minutes the attack passed 
away, leaving the patient more comfortable than after any previous attack. 
This follows the “similia similibus curantur” of the Hahnemannian teaching 
and surely worked wonders in this one instance. No opportunity to repeat the 
trial, because one month later the patient was taken with another attack of 
a similar nature and before help could reach him, passed away. 

These observations and experiments of Dr. Coleman seem to me 
to be of themselves sufficient evidence to show the really deadly char- 
acter of Latrodectes poison. But there is other evidence of similar 
import, obtained in a different way. It is the evidence from the work 
of the Germans, Sachs and Kobert, on the hemolytic effects of spider 
poison, and the isolation from the spider body of a specific poisonous 
principle named “arachnolysin,’ which is a powerful hemolysin, proved 
by experiment to have very definite action on the blood of various 
animals, such as rabbits, rats, mice, geese and man. 

Dr Hans Sachs (Beitrage zur Chemischen Physiologie und Patho- 
logie, vol. ii) records the results of a study of the hemolytic action of 
the poisonous principle in the body fluid and poison glands of the 
diadem spider, Epeira diadema. The author first refers briefly to the 
present status of the general knowledge of the hemolytic effects of 


spider poison. By spider poison is not meant necessarily simply the 


KELLOGG—SPIDER POISON 111 


secretion of the poison glands, but also that substance carried by the 
body fluids or body tissues which seems to have, as well as the specific 
secretion of the poison glands, a poisonous effect on other animals. 
The author then describes elaborately the technic by which he made 
the extraction of a poisonous principle from the crushed and macerated 
whole body of the spider. This principle, the arachnolysin, causes, 
almost immediately, a dissolving of the sensitive blood corpuscles when 
introduced into blood taken from various birds and mammals, includ- 
ing men. In its behavior the arachnolysin shows a certain analogy with 
the venom of serpents and is distinguished by its immediate effects 
from the hemolytic behavior of blood-serum which acts only after a 
longer or shorter period of incubation. Curiously enough, the diadem 
spider’s poison had no effect on the blood of guinea-pigs, dogs, sheep 
or horses. Its strongest effect was on the blood of rabbits and rats, 
next On mice, next on that of man, next on that of the ox and last, 
although still fairly strong, on that of the goose. A diadem spider of 
1.4 gr. contains sufficient poison to destroy completely all the corpuscles 
in 2.5 liters of rabbit blood. This puts arachnolysin in the class of the 
strongest kinds of blood poisons. 

Arachnolysin is easily destroyed by high temperatures. If it is 
exposed to forty minutes’ continual heat of from 70 to 72 C. it is 
wholly destroyed. It can withstand a temperature of 56 C. for forty 
minutes, while a temperature of 60 C. for forty minutes reduces its 
effects only slightly. It can be preserved in glycerin for months in 
full strength of effect. 

Sachs made experiments on immunizing, but they were limited 
by lack of material and he gives very little account of them. How- 
ever, he mentions that shortly before his work was finished he was 
able to produce a highly effective antitoxic serum by treatment of the 
blood of guinea-pigs with arachnolysin; 0.0025 c.c. of this antitoxin 
serum is sufficient to protect 0.05 c.c. of rabbit blood from an other- 
wise hemolyzing dose of arachnolysin. 

Kobert (Lehrbuch der Intoxicationen, 1893; and Beitrage zur 
Kenntniss der Giftspinnen, 1901) describes his studies of the poison 
of the diadem spider and also of Latrodectes. He distinguishes between 
the actual secretion of the poison glands and a toxalbumen which 
exists everywhere throughout the whole body of a spider, especially 
in the legs and the eggs. (Dr. Coleman was able, it will be remem- 
bered, to kill a rabbit in two and one-half minutes and a cat in three 
minutes by injecting a solution derived from macerating the eggs of 
Latrodectes.) The more of the toxalbumen which penetrates the 
wound, so much the stronger, according to Kobert, are the general 
poisonous effects. While the more of the actual secretion of the poison 


112 THE SOURNAL OF (PARASITOLOGY 


glands which goes into the wound, so much the stronger are the local 
effects, especially in the case of species of Latrodectes, which “produce 
by their bite,” says Kobert, “the most serious general results, and are 
capable of killing even men.” The secretion of the poison glands may 
be made more dangerous by far by its mixture with the toxalbumen of 
the general body. In the case of the diadem spider, Sachs found that 
while only local irritating results are produced by its bite, it possesses 
also in its body a toxalbumen analogous to that determined by Kobert 
for the Latrodectes, which, however, does not form part of the secre- 
tion of the poison glands. In the light of this fact, Sachs holds it to 
be very probable that the hemolytic results described by him are 
practically identical with the results referred by Kobert to toxalbumen. 

Kobert describes the hemolytic working of both Latrodectes and 
diadem spider poison. He found the hemolytic effects of the latter to 
be real, but much less in degree than that of the Latrodectes poison. 
Kobert found the Latrodectes poison to be effective on dog blood 
which was one of the kinds of blood which Sachs found to be prac- 
tically immune to diadem poison, so that perhaps the Latrodectes 
poison would be found to be even more serious in the case of those 
kinds of blood which Sachs found to be affected by the diadem spider’s 
poison. Kobert also determined that a certain immunity or an accli- 
matization to Latrodectes poison as well as to diadem poison, can be 
brought about. 

The results of the careful work of Sachs and Kobert prove con- 
clusively the active and formidable character of spider poison. In 
ordinary biting by spiders, a very small quantity of poison finds it way 
into the wound; not enough to trouble, in most cases, a human being. 
But with Latrodectes the poison seems more effective. A small amount 
injected by a single bite can threaten the life of a man. Probably with 
Latrodectes, as with other animal poisons, the physiological idiosyn- 
crasies of the particular man bitten play an important part in determin- 
ing the degree of seriousness of the trouble produced. Some of us are 
badly injured by a bee’s sting; most of us are not. To most of us a 
rattlesnake’s bite would be serious; to a few of us, it would not be. 
I can believe that the bite of Latrodectes would not be serious to cer- 
tain men; I must believe that it can be serious to some; for it has been. 


SARCOSPORIDIA ENCOUNTERED IN PANAMA 
S. T. DARLING 


From Board of Health Laboratories, Ancon, Canal Zone. 


During the routine examination of nearly one thousand animals 
that have come to autopsy here and have been specially examined for 
parasites, Sarcosporidia have been detected in three new hosts: 
opossum,! hawk and sloth. The following animals were also found to 
be parasitized: horse, cow, hog, sheep, cat, man* and rat, Mus. rattus 
and Mus. norvegicus.’ 

Most of the sarcocysts of the common species were found to 
resemble closely those described from these animals by other writers. 
The sarcocyst of man, however, presented a different appearance from 
the one described by Baraban and St. Remy from the laryngeal muscles 
of man in that the former exhibited younger and apparently abortive 
cysts. Sarcosporidiosis appears to be far more widespread among 
various animals than has been supposed. Some host species appear to 
show a constantly high incidence of infection; others, as man, for 
example, seem rarely infected. 

The infection is a common one, but it probably has little path- 
ological significance or economic importance. It is extremely rare here 
to find an animal other than a rat visibly infected and those sarcocysts 
encountered microscopically display little or no evidence of having 
induced any tissue reaction. 

Some animals retain permanently evidences of the infection, but my 
observations in a case of infection? of a negro lead me to believe that 
sarcocysts may be abortive and after a short residence in the muscle 
fibers disappear in various ways. 

Interest in Sarcosporidia centers in their life cycle, and considering 
the large number of infected animals accessible for experimentation, 
it is remarkable that so little light has been thrown on the subject. This 
is very largely due, no doubt, to the view that the sarcocysts are not 
pathogenic® and are of doubtful economic importance. 

Sarcosporidia of birds have been described by Kuhn, Leidy, Rivolta, 
Barrows and Stiles,* the following birds having been parasitized : com- 


1. Bull. de la Soc. Path. Exot., iii, p. 513, 1910. 

2. Arch. Int. Med., April, 1909. 

3. McGowan: Investigation into the disease of sheep called “Scrapie.” 
Blackwood, Edinburgh, 1914, p. 116, believes that “Scrapie”’ is due to Sarco- 
sporidiasis. 

4. See Bull. No. 3, B. A. I, U. S. Dept. of Agr., 1893. 


114 THE JOURNAL OF PARASITOLOGY 


mon fowl, Gallus, blackbird, raven, shoveler, spoonbill duck, mallard 
duck, grosbeak, and two Brazilian birds, Aramadis saracura and 
Amimodromus manimbe.® 


SARCOCYST OF THE HAWK: Leucopternis sP. 

The sarcocysts were detected microscopically and had invaded the 
striated muscles of the leg, and presumably elsewhere. The muscle 
fibers of smaller size were usually invaded, for the sarcocysts in cross 
section were 29 and 20 yp in diameter, while the diameter of the muscle 
fibers nearby was only 16 p. 

Muscle fibers of larger size were also parasitized for one sarcocyst 
was 48 » in diameter with a limiting membrane or false capsule of 
muscle substance 6 » in thickness. This was not striated and was of 
lighter color than neighboring muscle fibers which were 32 p» to 44 p in 
diameter (Figs. 3 and 4). 

The sporozoites were 4.5 » long and 1.2 to 1.5 » wide with a nucleus 
in one end apparently about 1.0 » in diameter. The sporozoite stains 
rather diffusedly with hematoxylin. <A definite reticulum cannot be 
made out, but there are clear spaces within the sarcocyst indicating the 
presence of sporoblastic chambers. z 

A few small parasites 12 » in diameter have invaded the muscle 
fibers of the heart and here they have a thin but definite limiting cap- 
sule and are located in the inner circular layer. None was seen in the 
outer longitudinal layer of fibers. 


SARCOCYST OF THE SLOTH 


The tissues of this animal Choloepus didactylus as well as of several 
other individuals were searched for sarcocysts, but not until a micro- 
scopic examination of sections of muscle was made were any found, 
the sarcocysts being found in the esophagus and muscles of limbs and 
trunk. 

The sarcocysts were always found within the muscle fiber enclosed 
in a very thin capsule. One sarcocyst measured 0.033 mm. in diameter, 
its muscle fiber being 0.051 mm. in diameter. Another occupied the 
entire width of the muscle fiber. The muscle of the esophagus was 
more highly infected than other muscles and the sarcocysts were more 
frequently found in its middle longitudinal layer of fibers. 

None was found in the heart. Not all the sections of muscle 
examined were parasitized, however, and none was found in viscera 
examined: kidneys, lymph nodes, spleen, liver and lungs. In the 
infected muscle the sarcocysts were packed with sporozoites or sporo- 
blasts, which were either banana-shaped or round. Isolated spores were 


5. See Splendore, Rev. d. Soc. de Sao Paulo, pp. 115-120, 1907. 


Fig. I 


DARLING—PANAMA SARCOSPORIDIA 115 


examined with difficulty on account of their being so closely packed 
together in the cyst. 

Altogether the sarcocysts resembled those seen in man, opossum, 
and guinea-pig experimentally infected with S. muris. Apparently, 
there are two well-marked types of sarcocysts, those with large sporo- 
blasts seen in rat, sheep, cattle and horse, and the type with very small 
sporozoites or sporoblasts encountered in man, sloth and opossum. 

Considering the results of the experiments of Negri, and the writer, 
with “S. muris” as well as those of Erdmann with “S. tenella” in which 
there was a reduction in the size of the sporozoite encountered in the 
sibinoculated animals it seems likely that the size of the sporozoites in 
the sarcocyst may depend on the host and be irrespective of the variety 
of sporozoite inoculated. 


SSARCOCYST OF THE OPOSSUM 


This remarkable parasite was found in the opossum Didelphis sp. 
distributed to the voluntary muscles and heart and also in the lungs, 
stomach, small intestine (Fig. 1), and its mesentery, pericardium, sub- 
maxillary gland, and esophagus, but not in the kidney, liver, spleen, 
pancreas, bladder, gall-bladder, external genitalia, or eye and extrinsic 
muscles. For this reason the definition of Sarcosporidia must be 
amended to include representatives which from the very start lodge 
and develop in non-muscular tissue. 

All the parasites were of one size and age. 

The attempt was made to infect guinea-pigs by the intramuscular 
inoculation of sporozoites ; and in one of two guinea-pigs so inoculated 
with the opossum parasite and sacrificed sixty days after inoculation, 
Sarcosporidia were found in sections of muscle from the leg inoculated. 
The other guinea-pig, when sacrificed after a period of 146 days failed 
to disclose parasites in tissue from either leg. 

The Sarcosporidium found is believed to be of an abortive type and 
probably does not experience further development, but dies out early. 
The feeding habits of the host suggested at the time that the parasite 
might have been derived from poultry, and one out of a good many 
fowl examined, a black Orpington, contained lime-infiltrated bodies 
grossly not unlike the Sarcosporidia found in the opossum. While the 
rat, cat, hawk and other animals revealed Sarcocysts of different ages, 
in the opossum they were all of one age. Apparently there had been 


but one infecting period and no auto-infection as described by Negri 
in other forms. 


116 THE JOURNAL OF PARASITOLOGY 


SARCOSPORIDIA OF THE CAT 


Wasielewski® states that Sarcosporidia have been found in the 
domestic cat, and Railliet’ quotes Krause as having discovered these 
parasites in the ocular muscles of the cat. 

A vagrant cat, much emaciated and dying of starvation, was caught 
near the laboratory. After being chloroformed it was noted that a 
large chicken bone had become wedged between the back teeth effec- 
tually preventing the use of the jaw. There was found a severe itch 
mite dermatitis of both ears and a number of intestinal cestodes and 
nematodes. 

No gross evidences of sarcosporidiosis were noted at autopsy, but 
from the size of some of the parasites detected later in sections of 
tissue the infection must have been visible macroscopically if the 
muscle had been more carefully scrutinized. 

Microscopically, there was extreme atrophy of the spleen and 
vacuolar degeneration of renal epithelium as in starvation. Striated 
muscle contained many parasites 24 to 160 » in diameter, the normal 
muscle fibers nearby being 24 to 40 » in diameter. There was an 
extremely delicate limiting membrane with delicate prolongations sug- 
gestive of sporoblastic chambers. The muscle substance enclosing the 
parasite was paler in color and more refractile and granular than 
neighboring muscle. In the larger parasite the sporozoites or sporo- 
blasts were in agglomerated masses. 

A few very young parasites were seen containing sporoblasts 
(Fig. 5) very much like those of .S. tenella and there was no limiting 
membrane or capsule visible. The sporozoite in sections appears to be 
about 7.5 p by 1.5 p. 

SARCOCYST OF MAN 

This was detected during life in the biceps of a young negro.? 
Examination disclosed small sarcocysts one-third to one-half the 
diameter of the muscle fiber, distended with vesicular sporoblasts. The 
parasite was of the minute or abortive type such as Negri and I have 
found in guinea-pigs fed with sarcocysts from the rat and differed 
from those described from the laryngeal muscle of a man by Baraban 
and St. Remy in that the latter were much larger, possessed sporoblastic 
chambers, and were of a more mature type. Four months after the 
parasite had been detected, another examination of tissue showed that 
apparently they had entirely disappeared. 


SARCOCYSTIS MURIS 


This form was frequently encountered during the routine bacteri- 
ological examination of rats from Panama and the Canal Zone. The 


6. Wasielewski, Sporozoenkunde, Jena, 1896, p. 119. 
7. Railliet, Zool. Médic. et Afric., 1895, p. 154. 


DARLING—PANAMA SARCOSPORIDIA 117 


young and immature rats usually showed no signs of gross infection, 
but when muscle was examined microscopically small sarcocysts were 
sometimes detected. Out of 131 adult rats examined grossly, 15 or 
11.4 per cent. were infected. Mus norvegicus showed a higher per- 
centage of infection (10.7 per cent.) than M. rattus (3.5 per cent.). 
There was never the slightest indication of cellular proliferation or 
necrosis in the muscle fiber of the infected rats and the animals all 
appeared to be in good physical condition. 

Feeding experiments were carried out with S. muris on guinea-pigs. 
Four pigs proved negative upon microscopic examination of several 
blocks of muscular tissue, but after a period of 164 days Sarcosporidia 
were detected in sections of muscle from two guinea-pigs; the mor- 
phology, however, was different from that of the sporozoites fed from 
the rats in that the former were much smaller and resembled those seen 
in tissue from the biceps of the human case and in guinea-pigs inocu- 
lated intramuscularly with sporozoites from the sarcocysts of an 
opossum. 

SARCOCYSTIS TENELLA 


There are no sheep in Panama. Occasionally a lamb is brought in 
from Peru to be kept as a pet, but for some reason they do very poorly. 
One such lamb died and was examined at the laboratory. At the 
autopsy there was a slight amount of pericardial clear fluid, general 
glandular enlargement and splenization of the lungs. Microscopically, 
there were many epithelial necroses in the kidneys and a few small 
Sarcosporidia in muscle fibers of the esophagus 22.5 m in diameter. 
These were very yoting parasite and corresponded to the description of 
S. tenella (see Railliet). 


SARCOCYSTIS MIESCHERIANA 


During a histological examination of hogs that had died of swine 
fever, sarcocysts were detected in striated muscle. The hogs were red 
Jersey, Berkshires and natives, and were bred in Panama. They con- 
tained young parasites with very large sporoblasts 3 by 8 u or larger in 
sections. 

SARCOCYSTIS FUSIFORMIS 


Case 1. Material was obtained from an emaciated cow of the 
hospital dairy herd originally from the U. S. A., that had died of 
puerperal pyemia. Some large sarcocysts were seen in striated muscle. 
The muscle fiber enclosing the parasite was altered into two layers, an 
inner dark or granular layer and an outer paler layer, paler than the 
muscle nearby (Fig. 2). The sporozoites are very large and apparently 
packed in room systems. 


118 THESIOURNAL OF «PARASITOLOGY 


Case 2. Emaciated cow, from the Ancon dairy herd, originally 
from the U. S. A. The autopsy findings were bronchial strongyles, 
liver necrosis and aneurysm of hepatic artery. The esophagus contains 
some large sized sarcocysts with a definite thin inner lining and a 
thicker grayish eosin colored capsule with radiating striations (see 
figure as in S. tenella). There is a delicate eosin staining reticulum 
making the room systems (sporoblastic chamber or capsule). 

This sarcosporidian has also been detected in muscle tissue of beef 


from Argentina. 
SARCOCYSTIS BERTRAMI 


An emaciated mule from the U. S. A., 14 years old, died suddenly 
without assignable cause of death. Sarcocysts with large sporozoites 
3 by 9 » with eosin staining cytoplasm were detected in striated muscle. 


DISCUSSION 


The deepest mystery surrounds the life history of the Sarcosporidia. 
Minchin says that in the present state of our knowledge the Sarco- 
sporidia would appear to be true Cnidosporidia with spores which con- 
tain each a single polar capsule and from which an amebula is liber- 
ated as in other Neosporidia. 

Theobald Smith® succeeded in infecting mice by feeding muscle 
tissue of infected mice to non-infected animals, and while cannibalism 
and carnivorous habits may spread the infection among certain animals 
it is certainly not the way the disease is transmitted to sheep and cattle. 
Watson, according to Minchin, stated that spores are to be found in 
the circulating blood, but McGowan believes that Watson was very 
indefinite on the subject and his remarks may not bear that inter- 
pretation. 

In attempting to account for the Sarcosporidium of cattle Smith 
states “their muscle parasite is either an aberrant form from some 
invertebrate taken in with their food or else there is an intestinal stage 

” Professor Smith further states that he desists “from any 
further discussion not based on actual studies.” 

According to Minchin,® who follows Erdmann, the spores germinate 
in the intestines of the new host. There is a liberation of sarcotoxin 
which destroys the epithelium. Amebulae are set free which penetrate 
into lymph spaces of the submucous coat. By analogy this represents 
the planont or first stage, it is initiated by sexual processes. 

The second stage represents invasion of muscle fibers and develop- 
ment of amebulae therein, first by a multiplication of nuclei until 
about twelve nuclei are seen. The parasite becomes divided up into 
separate cells or pansporoblasts or sporonts which actively multiply 
by division. This stage is reached in forty-eight to sixty days. The 


8. Smith, Jour. of Exp. Med., vi, 1901. 
9. Minchin: An Introduction to the Study of the Protozoa, 1912, p. 422. 


DARLING—PANAMA SARCOSPORIDIA 119 


parasite may disintegrate at this stage setting free sporonts or may 
develop into a Miescher’s tube. If the former, there is wandering out 
and invading other muscle cells ; in the latter development of an enclos- 
ing membrane with chambers occurs. Fully formed spores are found 
in parasites eighty to ninety days after the infection of the host. 

Thus, Sarcosporidia belong to a group of sporozoa, the Neosporidia, 
which often occur in invertebrates as in the larva of the silk-worm 
moth, and the mode of infection is contaminative, i. e., by ingestion of 
spores on leaves and by an hereditary way in which ova are infected. 

Fantham and Porter,’® in an investigation of the pathogenicity of 
Nosema apis to insects other than hive bees, found that humble bees, 
mason bees and wasps became infected. 

Cabbage plants near a badly diseased hive were found spattered 
with bee excrement. Dead larvae of cabbage-white butterflies also 
were found, whereupon it was ascertained that when this larva was 
fed on spore-infected honey-cabbage the larva became infected and 
diseased. 

Cinnabar and gooseberry moths were infected experimentally. 
Blowflies. craneflies and sheep keds were also infected experimentally. 
This investigation of Fantham and Porter’s indicates that Nosema is 
capable of causing infection and disease in quite a range of invertebrate 
hosts and the wideness of the range suggests the possibility that ver- 
tebrates might be as easily infected. 

The animals most highly infected with Sarcosporidia, i. e., high 
incidence of infection, are pigs, sheep, cattle and horses, i. e., non-flesh- 
eating animals. If Sarcosporidia are obligate parasites for mammals 
and other vertebrates, the contaminative mode of infection from mam- 
malian and vertebrate hosts seems to be out of the question, for the 
spores cannot be liberated from the muscles, and, so far as we know, 
do not escape by way of the intestinal tract of the host to infect his 
environment; nor is it likely that they get into the blood stream. 

In the case of mice, rats and carnivorous animals the mode of 
infection may in part be by way of the intestinal tract through eating 
infected tissue; but the infection of sheep, cattle and horses cannot be 
explained in this way. 

On account of the facility with which herbivora may obtain and 
ingest invertebrates infected with Neosporidia, but more particularly 
flowers, leaves, etc., or water contaminated with droppings of bees, 
moth larvae, fly droppings, etc., or other material containing Neo- 
sporidia spores, is it not possible that Sarcosporidia may be sidetracked 
varieties of some of the Neosporidia of invertebrates which have 
invaded the musculature of a hospitable though by no means definitive 
host and are unable to continue further their life cycle and escape from 


10. Ann. Trop. Med. and Paras., vii, 1913, p. 569. 


120 THE JOURNAL OF PARASITOLOGY 


a compromising and aberrant position? The strikingly high incidence 
of infection among hogs, cattle, sheep and horses might be explained in 
this way. 

While many parasites are obligate in their host relationships there 
can be no doubt but that certain protozoa, usually parasitic in inverte- 
brates, may more or less readily succeed in establishing a foot-hold in 
the tissues of man or other mammal and cause a definite pathological 
condition therein. Take dermal leishmaniasis for example. In 1910 a 
solitary cases of this disease was detected here in a man that had been 
bitten by a tabanid fly out in the bush. Since that date some five or six 
others have been identified here by the presence of intracellular para- 
sites morphologically identical with L. tropica. Now, if L. tropica is 
an obligate specific parasite for man, it is very unlikely that Tabanids 
or other biting flies are carrying it about in the Canal Zone and only 
half a dozen cases arise in as many years. At the’ time I suggested 
that the sore was the result of an infection by an insect flagellate, and 
the subsequent incidence of the disease now emphasizes the importance 
of this view very strongly. 

Considering the infrequency of dermal leishmaniasis in this region, 
the sparseness of the parasites in many of,the ulcers and the extreme 
unlikelihood of an insect being able to penetrate the tough crust of the 
ulcer or of the papule to regain the flagellate and carry it on, it seems 
unlikely, assuming that there is a specific form of the virus of oriental 
sore, that it could be propagated in a region without our being able to 
detect many more examples of it if it were necessary for its life cycle 
to be carried out in an insect as well as man. 

Under the circumstances it is far more probable that the dermal 
leishmaniasis of Panama at any rate is “a disease caused by the inocu- 
lation of one or more varieties of insect flagellates.” 

If this should prove to be true then the parasites in the sore are 
permanently sidetracked in the tissues of man and have no natural way 
of continuing their life cycle in the variety of insect from which they 
originally came. It is possible that other protozoa, and among them 
Neosporidia, meet with similar fates, the latter becoming sidetracked 
in the muscle fibers as “‘sarcosporidia” (as well as in other tissues 
occasionally, such as that of opossum and kangaroo) and while 
attempting blindly to continue their life cycle in their vertebrate host 
have no further opportunities for completing the same. 

Experiments with Nosema or other Neosporidia would settle the 
matter at once, and I regret that no material has been encountered 
here with which these views on the probable zoologic status of Sarco- 
sporidia might be tested. i 


11. Darling: Arch. Int. Med., Chicago, 1911, vii, p. 581. Proc. Soe. Trop: 
Med. and Hygiene, Lond., 1910, iv, No. 2, p. 60. 


OTACARIASIS IN THE BIGHORN * 
Henry B. Warp 


In March, 1914, Mr. G. H. Thomson, superintendent of the Estes 
Park Fish Hatchery, Colorado, sent me a vial containing some material 
he had taken from a mountain sheep the previous December. Con- 
cerning the material, Mr. Thomson wrote as follows: 


Last December we had a very severe fall of snow so that there was five 
feet on the level, which made it next to impossible to get around, and which 
made it exceptionally hard on our wild game. I found a two-year-old moun- 
tain sheep that had been separated from the bunch by a mountain lion and was 
tired out in the deep snow; with the help of others I got it on my horse and 
brought it home with me, and have had it since that time. It has been very 
interesting but some time after I had it here I found that it had some trouble 
with its ears from scaling off and the hair came out on its head; I treated it 
with vaselin and liniment which seemed to help it but the affection seemed 
to come from its ears on the inside. They would scale off down deep in the 
ears and block up its passage; I have opened them and have examined them 
very closely but could not find out the trouble. I have examined the scale 
under a heavy glass but even then failed to find the trouble; but this morning 
a portion of the scale looked different than usual as it came from deep down 
in the ears and upon examining it very closely I found that it was filled with 
a parasite. There did not seem to be any life in them, but when I warmed them 
up a little it was simply a mass of life. I am sending you a sample of the 
scale and also the scales with the parasites upon them and trust that they may 
reach you in life. 

I should like very much to know what they are and also what the final effect 
would be on the sheep if it was upon the mountain side where it could have 
no attention. The sheep is doing well and eats well both hay and grain and 
also potato parings and most everything that I give him. 


May 18 Mr. Thomson wrote again in reply to my inquiries, as 
follows 

From close observation of the sheep on the mountain side with a good glass 
there are not many that are affected, or if so not so badly as the sheep I had. 

I used a strong solution of carbolic acid and olive oil on the inside of the 
ear and cleaned them out so the ear cleared up, and it was that way for some 
time but they came back later and I had to treat it again. I then sent it to 
the City Park at Denver so I have not been able to follow it lately. 


Ihe specimens arrived in good condition and were observed living 
for some time. Even at the first glance it was possible to determine it 
as a mite of the group known as Itch or Scab Mites, the Sarcoptidae. 
A study of both living and preserved material was made to determine 
more exactly the structure and relationship of the form. 


*Contributions from the Zoological Laboratory of the University of Illinois, 
No. 40. 


122 THE JOURNAL OF PARASITOLOGY 


The full-grown ovigerous female (Fig. 1) measured from 680 to 
750 microns in length and 425 to 545 microns in breadth; its average 
dimensions were 720 by 460 microns. Young females were 500 to 580 
microns long by 390 to 440 microns wide, or on the average 535 by 410 
microns. The male measured 490 to 570 microns long by 325 to 390 
microns in width, with an average of 515 by 550 microns. The eggs 
measured varied from 275 to 355 microns in length by 120 to 220 
microns in width; the average of undistorted specimens was 330 by 
195 microns. 

The form of the appendages can be most easily described by refer- 
ence to the illustrations, which were made from camera drawings. 
Characteristic are the jointed stalked suckers (Fig. 5) that terminate 
the first, second, and fourth pairs of legs in the female (Figs. 2, 4, 6), 
whereas the third pair ends in two long slender bristles (Fig. 8). The 
mouth parts (Fig. 3) are apparently peculiar to this form and differ 
from any figured for species previously known in the genus. One can 
readily determine the numbers and location of the fine bristles occur- 
ring on each joint of each appendage, and also on the various regions 
of the adult female, which is illustrated (Fig. 1). 

The male, which is not illustrated here, has two well-developed 
caudal lobes carrying long stout bristles. There is a conspicuous suck- 
ing disk at the base of each caudal lobe alongside the anal orifice. 

As a rule, authors have sought to differentiate species by more 
conspicuous details of structure and by the type of scab produced while 
the varieties were named after the host on which the form occurred. 
In general, very few species have been recognized, sometimes only a 
single one, but with many varieties in a genus. Ability to transfer the 
parasite experimentally from one host to another has also been accepted 
as a measure of relationship, and those forms which cannot be trans- 
ferred have been elevated from varietal to specific rank. Such physio- 
logical data are of great interest, but can hardly be accepted as ade- 
quate evidence of systematic position. When more exact anatomical 
descriptions have been written and utilized to differentiate the species, 
one can hardly doubt that some will prove to have adapted themselves 
under experiment to several hosts, and others will be shown to be 
exclusive in habit. 

If now one seeks to find morphological data to distinguish species, 
it must be confessed that the descriptions given of the different species 
and varieties of these mites are unfortunately inadequate for accurate 
determination. For the most part the details cited by various authors 
are limited to the size of individuals of various ages and sexes; but 
these vary rather widely, even at the same stage of development, and 
the different varieties overlap in size so much that one might place a 


SSeS ea RAS 3 
és SRN eee ie 


© 


Fig. 1—Ovigerous female in ventral aspect. 


Y= 


A 


fi 


EXPLANATION OF PLATE 


Camera drawings of Psoroptes cervinae nov. sp. 


Fig. 2.—Distal joints of leg II. 
Fig. 3—Mandible and palp. X 
fig. 4—Distal joint of leg I. 


Fig. 
Big. 


Fig. 


Fig. 


5.—Jointed stalked sucker. 
6.—Distal joint of leg IV. 
7—lKge. X 120. 


$.—Distal joint of leg IIT. 


MS Stl) 
350. 
Me SHO). 
X 590. 
xX 350 


X 350. 


x 


29} 


WARD—OTACARIASIS IN THE BIGHORN 123 


given form in any one of two or three groups if that evidence alone 
were relied on. _ 

Many of the figures given by different authors are admirable, and 
even a superficial examination of them discloses differences in the form, 
size and armature of various appendages, such as are clearly adequate 
for the differentiation of the species. But in the text accompanying 
the illustrations these items are neither described nor compared suf- 
ficiently precisely to enable others to utilize the data for the determina- 
tion of species. This is not the place to enter upon an extended dis- 
cussion of these details. The latest monographic revisions of the 
sarcoptids leave much undecided and vague regarding the species, and 
until a further study is made of a large series of forms one can only 
arrive at a partial conclusion regarding supposed new material. 

The form under consideration unquestionably belongs to the genus 
Psoroptes, as it is described by Canestrini and Kramer (1899). These 
authors recognize only five species and confess that these are not well 
defined. The species are all named from their hosts; three Ps. bovis, 
Ps. equi and Ps. ovis produce the psoroptic scab well known on these 
hosts; Ps. cuniculi gives rise to auricular scab in rabbits; Ps. gazellae 
is extremely briefly described, and no data as to its origin and hosts 
or the disease produced are given at all. To these species must 
be added Ps. caprae, described by Railliet (1893). While the data 
given for the species are few, it seems that both because of size and 
because of the type of scab produced the form under consideration can- 
not be placed in any one of the first three species. It differs also too 
clearly from the species reported from the rabbit to be included in 
that even tho the type of the scab is the same. The measurements 
show the Colorado form is very much like Ps. gazellae and Ps. caprae, 
but the data given are so extremely scanty that one would be subject 
to criticism for basing any final decision on such incomplete evidence. 

A comparison of the figures given by various authors to illustrate 
the species might be used to supplement the few general measurements 
they have recorded. The form from Colorado appears at once to be 
clearly differentiated from any other species which is figured. These 
differences are indicated by comparing the figure given here with those 
of Psoroptes given by Mégnin. Unfortunately for the purpose, all his 
illustrations seem to be made from the form found on the horse, which 
was formerly designated the typical variety of the single species in the 
genus, but is now regarded as one of the several distinct species. On 
comparison with this, the Colorado form appears to have a rostrum 
materially shorter and broader than in Ps. equi, designated longirostris 
by Mégnin; the proportions of the appendages do not agree with those 
in Ps. equi, and the stalked suckers are distinctly shorter as well as 


124 THE JOURNAL OF PARASITOLOGY 


apparently more slender in the Colorado form. Moreover, the shape 
of the body is not the same in figures of the two species. While these 
are apparently minor discrepancies, I consider them adequate to justify 
fully the separation of these forms as distinct species. 

Unfortunately, no figures at all have been published for the species 
which in size most closely approximate this form. Of Ps. gazellae the 
describer (Canestrini, 1894) gives only scanty data regarding its gen- 
eral size. He says, further, that it is very similar in size to Ps. equi 
and in the type of scab that it produces to Ps. cumiculi. No data are 
furnished concerning the origin, geographical distribution, hosts or 
effects. To diagnose a species on this description would be ven- 
turesome. 

Railliet (1893) has given a more extended description of Ps. caprae 
by referring to the records of other authors. His remark that an 
analogous observation was made by Ugo Caparini on a gazelle very 
likely refers to the material which was the basis of Canestrini’s 
description of Ps. gazellae. But here again precise evidence is wanting 
to determine whether the Colorado form belongs in this species, of 
which more is said later in this paper. I am of the opinion that these 
two (Ps. caprae and Ps. gazellae) are the same species, and indeed it 
is impossible from the data given to separate them save by the hosts, 
which is an unreliable method. Yet it would certainly introduce even 
greater confusion than now exists to assign the Colorado form to either 
species in the light of the present scanty knowledge concerning both. 
The wide geographic separation of these hosts and the inadequate 
evidence on which to base a demonstration of the identity of the para- 
sites together with the structural peculiarities of the Colorado form 
compel me to list the latter as a new species for which I suggest the 
name Psoroptes cervinae. 

Ear scab, or otacariasis as it has been appropriately designated by 
Neumann, is not a frequent complaint but scattered references to such 
trouble are found in the literature. In 1834 Hering found a mite in 
the dog’s ear; since then it has been discovered in the same and other 
hosts and renamed many times. It seems to be fairly common in dog, 
cat, and ferret in Europe. Many observers have commented on the 
severe epileptic attacks to which the infected animals are subject. 
These are especially sudden and violent among hunting dogs engaged 
in the chase. 

This form lacks the caudal lobes on the abdomen of the male and 
has been made into a separate genus, now designated Otodectes, of 
which at least two species are known, O. cynotis Hering and O. furonis 
Railliet. Banks (1904:99) says that the first species has been taken 
in this country. These species are both so distinct from the Colorado 
form discussed here that confusion is unlikely. 


WARD—OTACARIASIS IN’ THE BIGHORN 125 


The Colorado form is also a very different mite from that reported 
by Leidy (1872) which was found in the ear of an ox.* That form 
belongs to the Gamasidae or beetle mites, whereas the species under 
consideration here is grouped with the Sarcoptidae, variously called 
scab mites or itch mites. To this group belongs different species that 
produce various types of itch or scab in man and other higher animals. 
Many of those that frequent other hosts are transferable under cir- 
cumstances to man and produce on this host a type of itch which may 
be temporary and relatively insignificant or on the other hand lasting 
and difficult to eliminate. It is not known that any form of ear itch 
can be transferred to man. 

Auricular psoroptic scab, or psoroptic otacariasis, has been known 
in Europe where it was first reported by Pezas from the wild goat of 
the Pyrenees. The cause of the trouble was recognized as a mite in 
the external auditory meatus and the species was identified as Psoroptes 
communis var. caprae. The determination was confirmed by Pench 
and Neumann and in a second case by Mégnin and Railliet. Otacariasis 
was also observed in the Congo by Mense who regarded the cause as 
a special form of Psoroptes to which he gave the name of P. congo- 
lensis. However, Gedoelst (1909) has shown that the Congo form is 
the same species of mite as that which gives rise to the disease in the 
goats of the Pyrenees, or at most in his opinion a closely related variety. 
Mense reported that the goats became deaf, refused to eat, and in a 
few months perished. According to all these authors the malady is 
serious, and the prognosis grave unless the trouble receives immediate 
attention. This is naturally excluded whenever the trouble appears 
among wild animals and in the case of such the disease will necessarily 
run its course unhindered. 

The only mention I have found of scab on the mountain sheep of 
Colorado is printed by Warren (1906:238) who writes in his section 
on the Bighorn as follows: 

“C. F. Frey tells me they suffer much from scab in the West Elk 
Mountains and that a party told him in 1901, at one place near the 
head of Sapinero Creek seventy-five head were counted which had died 
of scab. Domestic sheep have been seen in that locality, and the wild 
sheep doubtless contracted it from them.” 


*In this connection I may correct a misstatement of Freund (1910), who 
says that Trouessart is in error, as all others before him, in citing the name 
of this species as Gamasus auris Leidy and that Leidy never used the specific 
name auris. To be sure Leidy did not employ that name on his first note 
(1872:9) read at the January meeting of the Philadelphia Academy, but did 
in his supplementary reference (1872: 138) made at the June meeting. Evi- 
dently Freund did not see the original of Leidy as he cites the pages incorrectly” 
as well as misstates the facts regarding the text. Leidy both described and 
named the ox ear mite. 


126 THE JOURNAL. “OF “PARASITOLOGY 


This is not the same complaint as the one described in this paper, 
but is that well known among domesticated sheep and designated 
usually as common sheep scab. Salmon and Stiles (1898) have given 
an extended account of that disease. It is highly contagious and 
probably easily transmitted to susceptible wild species by means of wool, 
scab, etc., scattered over the range. Treatment is essential and very 
few animals make a spontaneous recovery. So far as has been ascer- 
tained no observer has recorded auricular scab, or any trouble caused 
by a different species. Hall (1912) states he found the common scab 
mite of sheep on a mountain sheep, Ovis nelsom, which was suffering 
from scab in the National Zoological Park, Washington, D. C. No 
statement is made concerning the source of this infection. Since 
neither Salmon and Stiles, nor so far as I have ascertained any later 
author refers to auricular psoroptic scab, I am led to believe that it is 
at least uncommon among domestic sheep in this country. This accords 
with conditions abroad where its occurrence is noted only in the two 
regions named. 

Finally a word on the general import of the trouble reported in this 
paper. It is stated on the one hand that mountain sheep still exist in 
the United States in sufficient numbers to assure their continued 
existence if reasonable laws are enforced—except for the danger of 
disease. On the other hand little or nothing is known of the types 
of disease prevalent among these animals or the range and severity of 
the various maladies. In Colorado the Bighorn is believed to be 
increasing in numbers and this if true renders them more likely to be 
visited in that region by epizootics of some sort. Prominent among 
such are diseases of parasitic origin and the importance of calling 
prompt attention to attacks of such diseases needs no special elucid- 
ation. This is the justification for publishing a brief discussion of such 
a malady as that which has been brought to my attention through the 
observations of Mr. Thomson. 


SUMMARY 


The ear of a mountain sheep at Estes Park, Colorado, was found to 
be heavily infested with a Sarcoptid mite which was not the common 
scab mite of domesticated sheep but is new in this country. 

This form is similar to a mite found in the ear of goats in the 
Pyrenees and in the Congo. Nevertheless there is reason to consider it 
a new species and it is named Psoroptes cervinae. 

The complaint to which it gives rise is likely to be serious if its 
effects are like those of the related European form. The Bighorn has 
been very greatly reduced in numbers by other causes and this malady 
merits the closest attention as a real menace to its host. 


WARD—OTACARIASIS IN THE BIGHORN 127 


PAPERS CITED 


Banks, N. 1904. A Treatise on the Acarina or Mites. Proc. U. S. Nat. 
Mus., 28: 1-114; 201 figs. 

Canestrini, G. 1894. Prospetto dell’ Acarofauna Italiana. Parte via, pp. 
723-772; tav. 62-75. 

Canestrini, G., und Kramer, P. 1899. Demodicidae und Sarcoptidae. Das 
Tierreich, Lief. 7, 193 pp., 31 figs. 

Freund, L. 1910. Zur Kenntnis der Ohrmilbe des Rindes. Zool. Jahrb., 
Syst., 29: 313-332. 

Gedoelst, L. 1909. Le parasite de l’otacariase des chévres du Congo. Arch. 
Schiffs.-Trop.-Hyg., 13: 150-157. 

Hall, M. C. 1912. Our Present Knowledge of the Distribution and Impor- 
tance of Some Parasitic Diseases of Sheep and Cattle in the United States. 
Ann. Rept. Bur. An. Ind., 27: 419-463; 62 figs. 

Leidy, J. 1872. On a Mite in the Ear of the Ox.—Note on Gamasus of 
the Ox. Proc. Acad. Nat. Sci., Phila., 1872:9, 10, 138. 

Mégnin, P. 1880. Les parasites et les maladies parasitaires. Paris, 478 pp; 
26 pl. 

Railliet, A. 1893. Traité de zoologie médicale et agricole. Paris, 736 pp; 
494 figs. 

Salmon, D. E., and Stiles, C. W. 1898. Sheep Scab; Its Nature and Treat- 
ment. Ann. Rept. Bur. An. Ind., 14: 98-165. 

Warren, E. R. 1906. The Mammals of Colorado. Colo. Coll. Publ. 
9 : 225-274. 


TOCOTREMA LINGUA (CREPLIN) 


THE ADULT STAGE OF A SKIN PARASITE OF THE CUNNER AND OTHER 
FISHES OF THE WOODS HOLE REGION * 


EDWIN LINTON 
Washington and Jefferson College, Washington, Pa. 


In 1884 John A. Ryder published an account of a skin parasite of 
the cunner (Tautogolabrus adspersus). The diseased fish which fur- 
nished the material for Ryder’s paper were from two localities, Woods 
Hole, Mass., and Cape Breton, N. S., and had attracted the attention 
of collectors on account of a peculiar spotted and rough appearance 
due to the presence of cysts in the skin. While Ryder did not deter- 
mine the exact nature of the animal inhabiting these cysts he concluded 
that it was most probably a flat worm belonging to the Trematoda. 

In 1889 I noted the occurrence of similar cysts in the skin of a 
cunner (Linton, 1890). The appearance of the infected fish agreed 
with Ryder’s description, and each cyst opened contained an immaturé 
trematode. Again I recorded (1901) the finding of this parasite in the 
tautog (Tautoga onitis). Since that date I have found this parasite on 
a number of the species of fish of the Woods Hole region. They are 
of frequent occurrence on the winter flounder, tomcod and eel, less so 
on other fishes, while cunners and tautog are seldom wholly free from 
them. 

It was not until July 24, 1911, that an adult trematode was recog- 
nized as the final stage of the skin parasite. On that date I obtained 
from the intestine of the loon (Gavia imber) a large number of small 
distomes, 4,789 by actual count. Another loon was examined on Sep- 
tember 1 of the same year with similar results. It was at once noticed 
that these trematodes bore a close resemblance to the immature forms 
occurring in the skin cysts of the cunner and other fishes of the region. 
A re-examination of some cysts from the skin of fishes was at once 
made, and the young forms liberated from the cysts compared with 
adults and immature from the intestine of the loon. Details of this 
examination are given later in this paper. It is sufficient to state in 
this place that enough points of resemblance were made out to warrant 
the conclusion that the trematodes found:in the intestine of the loon 
are the adult stage of some, at least, of the immature encysted forms 
found in the skin of various fishes. 


* Contribution from U. S. Fisheries Biological Station, Woods Hole, Mass. 
Published by permission of Commissioner of Fisheries. 


LINTON—TOCOTREMA LINGUA 129 


These small distomes from the loon appear to be identical with the 
species originally named Distomum lingua by Creplin, as that species 
is figured by Olsson, and the anatomy of the peculiar genital sucker 
agrees with that shown for this species in the excellent description and 
figures of Jaegerskidld. Following is a description of the species based 
on my material. 

Tocotrema lingua (Creplin) Looss—-Small, body depressed, mar- 
gins, especially in the vicinity of the neck, with a tendency to. fold ven- 
trally ; outline varying from linear to pyriform but mostly oval, taper- 
ing toward anterior end and bluntly rounded posteriorly; greatest 
breadth, in adults with eggs, at the level of the folds of the uterus, 
which is usually at about the posterior two-thirds of the length. The 
neck is from one-half to two-thirds of the entire length of the worm, 
depending on the state of contraction, and the outline varies accord- 
ingly. Young forms without ova may be nearly linear in outline or 
broader in front of the genital aperture than behind that structure. 
Very minute scale-like spines cover the anterior part of the body 
densely. These are plainly shown on the surface and margins in front 
of the genital aperture. Behind that point they are seen with difficulty. 
The acetabulum is minute, and forms an anterior, internal muscular 
portion of the genital sucker. The genital aperture is situated on the 
median line, from the middle of the length to the posterior two-thirds, 
according to the condition of contraction of the neck. 

The oral sucker is subterminal and its aperture is circular. There 
is a very short prepharynx followed by the pharynx which is longer 
than broad, oval-elliptical, its length about equaling the diameter of the 
oral sucker. The slender esophagus is longer than the pharynx and 
may be more than twice as long. The forks of the intestine are slender, 
simple, and extend to the posterior end of the body. 

Near the posterior end of the body are the two testes which are con- 
tiguous, diagonally placed, and, as seen in compressed specimens, dis- 
tinctly lobed. In uncompressed individuals the lobes of the testes are 
often indistinct. The vas deferens is obscured by the folds of the 
uterus so that its course is difficult to trace. In a few specimens, which 
had a smaller number of ova than are found in most cases, a tubular 
seminal vesicle could be made out lying in a few loose folds dorsally 
behind the genital sucker. It terminates in an ejaculatory duct which 
lies in the dorsal portion of a short, papillary cirrus-like body (kegel- 
formiges kérper of Jaegerskidld) and empties into a genital sinus on 
the anterior margin of the cirrus-like body. The latter is surrounded 
by the muscles of the genital sucker. At the anterior margin of the 
right testis lies the relatively large seminal receptacle. In some cases 
this is nearly circular in outline; in others it is oval with the longer 


130 THE JOURNAL OF PARASITOLOGY 


diameter transverse. In sections it is seen to extend from the dorsal 
to the ventral wall of the body, but in the whole mounts it is perhaps 
more clearly seen in dorsal than in ventral view. 

Along the anterior margin of the seminal receptacle is the ovary, 
which may be in part obscured by the folds of the uterus. When the 
worm is flattened and the ova are not too numerous the ovary is seen 
to be distinctly lobed. The ovary, seminal receptacle and testes there- 
fore are massed together near the posterior end of the body. The folds 


Fig. 1—Adult specimen of Tocotrema lingua from Loon; dorsal view, in 
balsam. Length 0.84 mm. a, surface spines, 0.001 mm. long. 


Abbreviations Used in Figures: de, ductus ejaculatorius; e+, excretory ves- 
sel; ga, genital aperture; gp, genital papilla; gs, genital sinus; 1, intestine; 
m, ventral sucker; 0, ovary; ov, Ovum, ova in uterus; pr, prostate; sr, seminal 
receptacle; sv, seminal vesicle; ¢, testis; v, outlet of uterus; vd, vas deferens and 
seminal vesicle; vg, vitelline glands. 


LINTON—TOCOTREMA LINGUA 131 


of the uterus are crowded between them and the genital aperture, the 
ova appearing as a golden yellow mass which extends nearly from 
margin to margin. The ova are oval-elliptical and, compared with the 
small size of the worm, are of good size. The terminal portion of the 
uterus opens into a cleft or sinus at a point adjacent to and dorsal to 
the opening of the ejaculatory duct. The genital sinus lies in front of 
the organ, called in the explanation of figures the genital papilla, 
(Figs. 4, 5, 6, gp), communicates anteriorly with the ventral sucker, and 
ventrally with the genital aperture. The genital sucker is surrounded 


Fig. 2.—Sections thru dorsal portion of genital sucker; A, horizontal; B, 
transverse; C, sagittal. 


by a somewhat triangular area of cells which are probably prostatic. 
The vitellaria are diffuse and fill the posterior and lateral margins of 


the body to a point in front of the genital aperture where they meet on 
the median line. 


The excretory vessels were not completely made out. An excretory 
pore was distinguished situated dorsally at the posterior end of the 
body. From it a vessel was traced which passed between the testes. 
Transverse sections show a small lateral vessel on each side of the neck 


132 THE JOURNAL OF PARASITOLOGY 


region, but not distinctly enotigh to admit of satisfactory recon- 
struction. 


A nerve mass lying dorsal to the pharynx, with short anterior 
branches, and lateral nerves traceable posteriorly to the anterior 
borders of the vitellaria are visible in many of the stained and mounted 
specimens. 


Fig. 3—A. Young specimen from Loon; dorsal view, in balsam. Length 
0.55 mm. B. Young distome from cyst in skin of cunner, in balsam. Length, 
0.7 mm. 


. Dimensions of a living specimen in millimeters: Length 0.75; 
maximum breadth, 0.35; diameter of oral sucker, 0.07; ova, 0.04 
by 0.02. 

A specimen flattened under the cover-glass had the following 
dimensions: Length, 1.40; maximum breadth 0.70; diameter of oral 
sucker, 0.09; pharynx, length 0.04, breadth 0.03; ova, 0.047 by 0.023 ; 
genital sucker, 0.56 from the anterior end; bifurcation of the intestine 


LINTON—TOCOTREMA LINGUA 133 


midway between anterior end and genital sucker. Following are 
lengths and breadths of ten specimens taken at random from a pee 
number mounted in balsam: 


Length, 0.70 0.97 0.76 0.80 0:55 080 0.76 0.67 0.72 0.64 
breadth. O52 ~0.20) 0.35. 0.28 0:22 0.30". 0.27, 0.22. 0.28° 0.32 


The above measurements were made of specimens from the loon. 
Following are dimensions of four specimens taken at random from a 
considerable number mounted in balsam, from the herring-gull: 


Length 1.32 084 1.52 0.91 
Breadth 0.40 0.33 0.48 0.33 


Following is a record of the finds of Tocotrema lingua at Woods 
Hole. Some of these were made in 1904, but were not given special 
attention at the time of collecting. 

Colymbus auritus: Feb. 8, 1912; 1. 

Gavia imber: July 24, Sept. 1, 1911; very numerous on each date. Feb. 21, 
1914, 2, immature. 

Larus argentatus: Feb. 16, 17, 1912, numerous on each date. July 22, 1912, 
252; Sept. 4, 1912, few. Jan. 22, 1914, 150; April 29, 1914, 1; Sept. 28, 1914, 1. 

Larus atricilla: Aug. 12, 1904, 27 from one gull, 86 from another. Aug. 15, 
1913, 18 from one gull, 6 from another. 

Nyctocorax nictocorax: July 15, 1913; few, immature. 

Sterna dougalli: Aug. 3, 1904, 1; Aug. 12, 1904, 21. 

Sterna hirundo: Aug. 5, 1904, 1. 


The specimens recorded for January and February are from the material 
collected by Vinal N. Edwards. 


Young trematodes (Fig. 3B) from cysts taken from the skin of 
cunners, tautog, and other species of fish, were compared with speci- 
mens of Tocotrema lingua from the loon and other fish-eating birds 
with the following results: The body in each case was covered with a 
dense coat of minute scale-like spines of similar appearance; oral 
sucker, prepharynx, esophagus and intestinal rami agree ; rudiments of 
genital sucker, genital papilla, testes, ovary, sperm receptacle and 
vitellaria agree in relative positions to the finished structures in the 
adult. Furthermore nothing was seen in the one that contradicted any 
point in the other. 

A few immature specimens were found among the adults in the 
final hosts (Fig. 3A). These agree very closely in form with those 
removed from cysts in that the neck is wider than the posterior third 
of the body. With the maturing of the testes and ovary and the 
accumulation of ova in the uterus the posterior third becomes normally 
wider than the neck. 


134 THE JOURNAL. OF PARASITOLOGY 


SUMMARY 


Certain trematodes encysted in the skin of the fishes of the Woods 
Hole region are the young of an adult which lives in the intestine of 
the loon and other fish-eating birds. 

The identification of these encysted distomes with Tocotrema 
lingua renders Stafford’s name (Dermocystis ctenolabrt) for these 
encysted forms inapplicable. 


LITERATURE CITED 


Linton, E. 1900. Fish Parasites Collected at Woods Hole in 1898. Bull. 
U. S. Fish Com. for 1899, 281-296; pl. 40. 1901. Parasites of Fishes of the 
Woods Hole Region. Bull. U. S. Fish Com. for 1899, 462-463. 

Ryder, J. A. 1884 On a Skin Parasite of the Cunner (Ctenolabrus 
adspersus). Bull. U. S. Fish Com. for 1884, 37-42. 

Stafford, J. 1905. Trematodes from Canadian Vertebrates. Zool. Anz., 
28 : 682. 


ten Abit, Lip, BIsStTORY, AND STRUCTURE OF A 
BLOOD-SUCKING MUSCID LARVA (PROTO- 
CALEIPHORA AZUREA)* 


ALBERT F. COUTANT 


While studying the blood parasites Halteridium and Proteosoma, 
and the Filaria of the common crow (Corvus americana), my attention 
was attracted by an external parasite of some young nestlings which 
were brought into the laboratory. Observations on this parasite, which 
proved to be the larva of Protocalliphora azurea (Fall.), form the basis 
of this paper. The parasite is the immature form of one of the 
so-called “blue-bottle’ or flesh-flies, whose larvae are generally 
regarded as useful scavengers. More careful observations on the life- 
histories of many species, however, have shown that they may be, 
and often are, parasites of the higher animals. 

The work was undertaken with the double purpose of seeking 
further knowledge of this parasitic habit of certain Sarcophagidae 
and of increasing the knowledge of the systematic characters in the 
group. It was carried on in the Entomological Laboratory of Cornell 
University under the direction of Prof. Wm. A. Riley, to whom I 
am gratefully indebted for continued suggestion and aid. I am also 
indebted to Prof. O. A. Johannsen, whose aid in the systematic part 
has been invaluable. 


HABITS OF THE LARVA 


On June 13, 1914, two young crows were brought to me. They 
were from the same nest and from comparison with others which I 
had reared, I judged them to be about five weeks old. They were put 
in a cage separate from my other crows, and seemed quite normal, 
save for fright. Three days later, however, one of them died and a 
post-mortem examination was made. Crawling among the feathers I 
discovered several larvae which looked in general like those of the 
Muscidae. They were from four to nine millimeters in length and 
were wriggling actively among the feathers, as if accustomed to this 
habitat. None were seen actually attached to the bird and feeding. 
The surface of their bodies was not a white or creamy color, as are 
the bodies of most of the blow-fly larvae, but was more the color of 
dirt. The contents of the alimentary canal showed through the skin 
dull-red, giving the whole larva a brownish-red appearance. Eleven 


* Contribution from the Entomological Laboratory, Cornell University. 


136 THE JOURNAL OF PARASITOLOGY 


specimens were found on this bird. Most of them were among the 
feathers of the abdomen and were quite dry, but three were found in 
one ear cavity and were moist. The ventral part of the body of the 
crow had a number of small scab-like spots on it where the larvae 
had been feeding. 

From the color of the alimentary canal of the larvae, I judged them 
to be blood-sucking, although this habit is not common in the larvae of 
this family. To test this I cut one in half and smeared the contents 
of the alimentary canal on a slide. [Examination with the microscope 
proved conclusively that the alimentary canal was full of corpuscles of 
crow’s blood. The crow, on further examination, proved to have died 
of malarial fever and there were enormous quantities of Halteridium 
in its erythrocytes. On discoyering this I returned to the study of the 
blood from the larva’s intestirfe, using an oil immersion lens, and think- 
ing to find out whether the malarial parasites might become sexually 
mature here and give off the motile microgametes, as they do in the 
stomach of the Anopheles mosquito. I found no indication that this 
occurred. 

Afterwards the floor of the cage under the straw was examined, 
and in the dirt I found forty or fifty more of the larvae, of various 
sizes and ages, crawling vigorously. All of them had more or less 
vertebrate blood in them, some of the larger ones having less than the 
smaller ones. From this I infer that the larvae are intermittent feeders, 
probably spending most of their time in nature in the dirt and more 
compact part of the bottom of the nest. The same day while feeding 
and holding in my hands the other crow from this nest, I observed one 
of the larvae clinging by its anterior end to the tibio-femoral joint of 
the crow’s leg. Before I could examine it closer, the bird began to 
struggle and the larva released its hold; so I could not see the process 
of ingesting blood. Subsequently I placed larvae on my arm and in 
the hairs under the armpits, but they seemed very sensitive to handling 
and would not settle down to feeding. I made a number of attempts to 
rear the larvae on fresh and putrifying meat, flesh and liver of the crow, 
and beef. All of these experiments resulted negatively, except that 
one larva lived to pupate and died in this stage. 

On the same day the larvae were found, I secured two young chicks 
of about the same development and allowed two maggots to crawl into 
each ear cavity, making eight larvae in all. They seemed to irritate 
the birds, and soon the latter began to shake their heads and scratch 
their ears. In this way one of them succeeded in digging the larvae 
out of one ear, but the other six remained well in. I also tried to 
make the larvae “take hold” of the skin under the feathers of these 
birds, but they dropped off as soon as the chick shook itself. 


COUTANT—BLOOD-SUCKING MUSCID LARVA 137 


Two days later one of the chicks died but post-mortem showed the 
cause of death to be a tumor in the left cerebral hemisphere, not ccn- 
nected in any way with the experiment. One larva was found in the 
right ear of this chick, the only one left of the four put on it, and 
this one died soon after without reaching maturity. 

The fourth day after putting in the larvae, I examined the remain- 
ing bird’s ears with a soft probe. Both cavities were free of larvae. 
The chicks had been kept in a case with a false wire bottom, two 
inches below which was the true bottom covered with half an inch 
of soil so that if the larvae emerged they would not be eaten by the 
chick but might pupate. After finding that the larvae were not in the 
ears, the soil of the cage was gone over carefully but no larvae or 
pupae were found. 

Some of the larvae, especially the larger ones, were left on the floor 
of the crow’s cage and the nest was not cleaned up. Eight days later 
ten puparia were found under a large piece of paper on the floor of 
the cage. As the cages were screened from other flies, these must 
have come from the same larvae. Furthermore, they were identical 
with the one larva which did pupate in the laboratory. The pupae 
were in quite a dry place, away from the wet fecal matter of the cage. 
They were removed to a stender jar and kept moist with a wet filter 
paper hung in the top of the jar. 

In the hope of learning more of the habits and distribution of these 
larvae, I began visiting birds’ nests in the vicinity of Ithaca. I went 
first to the crow’s nest from which the infected birds were taken, just 
one week after their removal. Crows’ nests are from one and a half 
to two feet in diameter; six inches to a foot deep, and contain a large 
quantity of rich moist earth below the grass which lines the nest. They 
are seldom used more than one year. I examined the debris and earth 
of this nest carefully but found neither larvae nor pupae of the form 
I was seeking. Subsequently I examined three other crows’ nests but 
found none of the parasites. I have also examined seven swallows’ 
nests (Hirundo erythrogaster), all but one of which still had young in 
it. These also had no larvae. In a house-wren’s nest (Troglodytes 
aedon) in a hollow stump, one anthomyid larva was found, but no 
Protocalliphora azurea. Two sparrows’ nests (Passer domesticus) 
yielded negative results, as did the examination of one robin’s nest 
(Merula migratoria). 

An instance of what was very probably an infection of Proto- 
calliphora was reported to me shortly after this by Mr. W. D. Funk- 
houser. While walking in the woods he found a nestling chipping spar- 
row (Spizella socialis) lying in the path. The bird was quite old, 
almost fully feathered and he could not think what ailed it. As he 


138 THE JOURNAL OF PARASITOLOGY 


held it in his hand a small dipterous larva crawled out from beneath 
the skin of the neck back of the ear. It was about a quarter of an inch 
long, and seemed to him of a whitish color. Mr. Funkhouser had no 
place to keep the larva so he did not save it. He brought the bird home 
but it died after a few hours and was not examined further. 

At the time these observations were made I had no idea that sim- 
ilar ones had been recorded before. They immediately suggested, how- 
ever, the case of the Congo floor maggot, Auchmeromyia luteola 
(Fabr.), which is also blood-sucking in its habit. The larva of this 
muscid, which is quite widely distributed in Africa, especially in the 
Congo region, parasitizes the natives by piercing the skin and sucking 
the blood. From the account of its habits given by Dutton, Todd, 
and Christy it appears to be an intermittent feeder, just as Proto- 
calliphora, living in the soil on the floor of the huts and feeding at 
night when the natives are sleeping on the ground. Roubaud (1913) 
mentions several species of the genus Choeromyia which occur in the 
Soudan and Timbuctoo regions, whose larvae have similar habits, and 
suck the blood of aard-varks and wart-hogs. But I was not aware 
that the occurrence of a blood-sucking larva on birds had been reported 
until the adult flies had emerged. Then on identifying them, I found 
the following accounts of the larval habits of this species. : 

The most careful discussion is given by Leon Dufour (1846). In 
the spring of 1845 he accidentally discovered some larvae on some 
young swallows in a wooden box-nest in his garden. He found many 
more of the larvae and some pupae on the floor of the box and on the 
ground beneath, and reared the adults. He noticed the “short and 
fine downy velvet” of the integument, which gave it a grayish appear- 
ance, and the “footless and headless” character, and soon guessed the 
larva to be a parasite. He dissected several specimens and found the 
alimentary canal full of a dark-red fluid which looked like blood, so 
he inferred that they were blood-sucking in habit. But he did not 
definitely know this and in fact was not completely assured of it, 
because he thought parasitism by such a large number of maggots, 
would almost necessarily affect the health of the young birds; but this 
was not the case, as the latter matured and flew. The same old pair 
of swallows had a second brood in mid-August which were less numer- 
ously parasitized than the first litter. 

Scheffer is reported by Rossi in 1848 to have taken the larvae 
of this species from a brood of larks. The larks died. Kirsch in 1867 
describes what are apparently the larvae of P. azurea crawling 
out of the neck of young sparrows. He did not rear the adults. 
Nowicki in 1867 also took the larvae from young sparrows. 


COUTANT—BLOOD-SUCKING MUSCID LARVA 139 


Brauer in 1867 took Protocalliphora azurea@ “subcutaneously” 
from nestlings of a swallow (Hirundo rustica) and P. chrysorrhea 
(Meig.), a closely related species from Hirundo riparia, According 
to Strobl in 1894 Schieferer took from the grass of a raven’s nest 
ten specimens of P. chrysorrhea, both male and female. 

In this country Henshaw (1908) notes the occurrence of Proto- 
calliphora chrysorrhea on two successive broods of blue birds in Massa- 
chusetts. The infestation was so severe that of eight nestlings only 
one survived. 

Du Buysson (1912) attempted to verify Dufour’s observations. He 
found the larvae on swallows June third and obtained pupae, but these 
had failed to emerge on August 23. He thought that they were resting 
and would emerge the following spring, but they were probably dead. 
Rodhain (1914:213) reports finding the larvae and pupae of a muscid 
in the nests of the grey-headed sparrow (Passer griseus) at Bambili 
in the Congo. He found that these larvae contained avian blood. They 
were reared but the adult fly had not been determined. It is not, he 
says, a species of Cheiromyia [misspelling for Choeromyia?]. 


CONCLUSIONS REGARDING THE HABITS OF THE LARVAE 


1. Dufour’s suggestion that the larvae sucked the blood of the host 
is definitely proved by my microscopic examination of the contents of 
the alimentary canal. 

2. The larvae play no part in the transmission of the malarial 
parasite. . 

3. They are intermittent feeders. This is based on the following 
facts: a) Many more larvae were found on the floor than were actually 
on the birds. b) They seemed perfectly at home there, and moved 
about in the refuse and on the dry floor quite naturally. c) They were 
very excitable, and would not settle down or take hold on a bird which 
struggled and were easily shaken off by the chick. d) One found 
feeding on a crow which was quiet, immediately released its hold and 
dropped to the floor when the latter became active. 

4. The larvae prefer rather dry places to moist ones and are there- 
fore not accustomed to living in decomposing or fecal material. 

5. The larvae do not feed on solid flesh, either fresh or decayed, 
although they may (Kirsch, Brauer and Funkhouser’s observations ) 
bore in living tissues. 

From these conclusions it is evident that the species Protocalliphora 
azurea is a blood-sucking parasite on nestling birds, that this habit is 
normal, not accidental, and that its effect on the host varies, in some 
instances (Schiffer, Henshaw) being fatal, in other cases (Dufour, 
my own observations) apparently not affecting the birds’ health at all. 


140 THE JOURNAL OF PARASITOLOGY 


The parasitic habit of this species shows a further step in specializa- 
tion among the larvae of the Calliphorinae. Some members of this 
group, as flies of the genus Pycnosoma, live only on the rich decom- 
posing organic excrement from man and other animals and are there- 
fore quite free-living. The next step may be represented by the species 
of blow-flies, Lucilia, Calliphora, Homalomyia, etc., which usually live 
in dead and decaying animal flesh. The tendency towards the parasitic 
habit is shown, however, in their accidental or facultative parasitism 
of the higher animals when they find an open sore or decomposing flesh 
near the living tissue. In such cases they cause myiasis just as do the 
more usual skin maggots (Chrysomyia, Cordylobia, etc.). The members 
of the genus Chrysomyia carry this habit further and usually develop 
in living flesh, wherever there is an abrasion of the skin or bleeding 
surface, though they can live in decomposing matter. The genus 
Cordylobia contains the “Thumbu fly” of Africa, C. anthropophaga, 
which normally gains access to and settles down under the skin, show- 
ing that it has become exclusively parasitic. Parasites which live on the 
cutaneous and connective tissues, however, have scarcely attained to 
as high a degree of perfection in the parasitic habit as those which 
live on the blood, the most nutrient tissue of their host. The extreme 
of parasitism in this group occurs, then, in the larvae of those genera 
which always puncture the skin and suck the blood of their host.. Of 
these there are but three genera known, the two in tropical Africa, 
Auchmeromyia and Choeromyia, and the genus Protocalliphora which 
has been found in Europe and North America. The length of life of 
the larva is probably between fourteen and twenty days. 


STRUCTURE OF THE LARVA 


Weismann in 1864 believed there were three larval stages or instars 
in the blow-fly (Calliphora). Hewitt (1908) has shown that there 
are three in the development of Musca domestica, and this is generally 
thought to be the number in the Muscidae. I presume that there are 
three larval stages in Protocalliphora azurea, although I have found 
larvae in the last two stages only. The structure of the larva is essen- 
tially the same as that described for the Muscidae and is best described 
by reference to the accompanying drawings (Figs. 1 to 5). 

The larvae are 6.0 to 7.0 mm. in length in the second instar and but 
little larger after the moulting. I find that there are but twelve 
segments in the larva. The first of these, called by Henneguy the 
“pseudo-cephalon,” corresponds to the head of the more generalized 
larvae, although in the Muscidae it is very much degenerated. In 
Protocalliphora it is small, membranous, and not covered with spines, 
as the following segments are. It differs from other larvae of the 


COUTANT—BLOOD-SUCKING MUSCID LARVA 141 


muscid type in that it is completely retractile, the entire segment being 
reflected, as Dufour says, “like turning a glove outside in,” when the 
larva is sucking. When extended it is divided on the ventral side by 
the pharyngeal cavity from the dorsal edge of which the two mandibu- 
lar hooks project. On the dorsal aspect the two halves of the segment 
are united over the hooks, and the lateral portions project cephalo- 
dorsad in two pairs of small tubercles. 

The mandibular hooks (Fig. 2) are the distal sclerites of a large, 
chitinized structure which extends back in the body as far as the second 
or third segment, and which is the chief prehensile organ of the larva. 
It is made up of several sclerites and is termed by Hewitt in the house- 
fly the “cephalopharyngeal skeleton.” The mandibular sclerites are 
two in number in Protocalliphora, as in Calliphora (Lowne) but in 


Fig. 1—Ventral aspect of second and lateral of third instar: X 10. (A) 
anus; (ap) abdominal pad; (asp) anterior spiracle; (At) Anal tubercles; 
(Ct) caudal tubercles; (/p) lateral pad; (ms) mandibular sclerite; (psp) pos- 
terior spiracle; (st) sensory tubercles. 


Musca domestica there is but a single median sclerite according to 
Hewitt. The remaining segments of the body present the peculiarity 
of being more or less covered with rows of sharp-pointed, hard, chitin- 
ous spines or scales. This spiny coat gives the larva the characteristic 
dirty brown color and velvety look previously mentioned, instead of the 
smooth creamy-white appearance which most muscid larvae have. In 
the second instar the spines are minute and some distance apart but 
after the next moult they are much larger and more closely packed 
and form a veritable coat-of-mail. 

I believe that the second, third, and fourth segments correspond to 
the pro-, meso-, and meta-thorax, respectively, agreeing with the inter- 


142 THE JOURNAL OF PARASITOLOGY 


pretation of Weismann, Brauer and Lowne. There is no evidence on 
any of my specimens of a constriction dividing the second segment into 
two, as Hewitt found in the house-fly, and the arrangement of spines 
may be taken as an additional indication that this is but a single 
segment. 

Extending cephalad from under the anterior margin of the third 
segment on the two lateral sides of the larva are the anterior spiracles 


Fig. 2.—Cephalo-pharyngeal skeleton in dorsal and lateral aspects. X 75. 
(dc) dorsal cornu; (hs) hypostomal sclerite; (/s) lateral sclerite; (ps) para- 
stomalsclerite; (vc) ventral cornu. 


Fig. 3 Fig. 4 
Fig. 3.—Anterior spiracles of larva; (a) second instar; (b) third instar. 
XO125: 
Fig. 4—Posterior spiracles of larva; (a) second instar, X 125; (b) third 
instar, X 250. 


(Fig. 3). They are small and probably not functional in the second 
instar, but in the third stage present ten well-developed ostioles or 
papillae, covered by a delicate membrane. Each ostiole has several 
small pores in it which apparently are functional. 

The fifth to the twelfth segments correspond to the abdomen. Each 
segment has on its ventral side, near its cephalic border, a transversely 


COUTANT—BLOOD-SUCKING MUSCID LARVA 143 


elongate, oval, elevated pad. These “locomotory pads’ (Hewitt) are 
homologous to the abdominal prolegs of lepidopterous larvae. In 
addition on the sides of the body there is between each of the segments 
except the last two, a small but constant spindle-shaped lateral piece 
(Fig. 1). 

The twelfth segment is considerably modified by the posterior spir- 
acles and the anus; its form and the arrangement of structures may be 
readily made out by reference to the figures. The posterior spiracles, 
two in number, lie in the depressed quadrilateral area of the segment 
which looks dorso-caudad. There are two large elongate ostioles, sur- 
rounded by a chitinous ring, in each spiracle during the second instar 
but there are three ostioles in the third (Fig. 4). 


Fig. 5—Caudal aspect of larva; second instar. X 20. (Jt) lesser tubercle. 


THE PUPA 


The larvae when ready to transform, apparently leave the more 
occupied parts of the nest in the vicinity of their food-supply and seek 
‘a dry, quiet portion, usually at the bottom. They seem to transform 
normally in such places, instead of in the earth as most of the Sar- 
cophagidae do. 

The adult emerges from the frontal end of the puparium as in all 
of the Cyclorrhapha. First a longitudinal slit is made in a frontal 
plane extending caudad from the larval mouth-opening in a line which 
passes just ventrad of the anterior spiracles. When this slit has been 
extended as far as the fifth segment, the dorso-ventral pressure on the 
two portions is so great that a circular splitting commences. This 
begins at the lateral faces of the fifth segment and extends dorsad 


144 THE JOURNAL OF PARASITOLOGY 


and ventrad far enough to allow the two anterior portions to spread 
apart as the fly emerges. They then spring back into place and usually 
remain attached, each portion connected to the rest of the puparium 
by a small part of the dorsal and of the ventral walls, respectively. 
Dufour noticed the longitudinal split on Protocalliphora, but thought 
that it occurred secondarily to the circular splitting. 

Whether this manner of splitting occurs in many of the Cyclor- 
rhapha or not is difficult to say. Most writers remark that the flies 
emerge by splitting off a circular “cap” at the anterior end. Hewitt 
however, in a careful study of the house-fly states that “the fly pushes 
off the anterior end in dorsal and ventral portions . . .” “The 
splitting of the anterior end of the pupal case is quite regular, a circu- 
lar split is formed in a line below, i. e., ventral to the remains of the 
anterior spiracular processes of the larva.” 

Professor Johannsen states that in all the individuals of the Calyp- 
terae whose puparia he has noticed, including Sarcophaga, Lucilia, 
Calliphora, and Musca, the “cap” is always split in a diametric line as 
well as circumferentially. 

The size of the puparium varies from 6.0 to 9.0 mm. in length, 
from 2.2 to 3.4 mm. in width (laterad) and from 2.1 to 3.2 mm. in 
depth (dorso-ventrad). Its general shape is that of a typical muscid. 
However, the puparium of azurea is not shiny, like that of Musca, 
Muscina, Lucilia, etc., but has a dull, blackish, and soft or velvety 
appearance. It is light brown, slightly reddish in color when held 
towards the light, but when looked at by reflected light it has a very 
dark or black color. This dull dark appearance is caused by the rows 
of spines of the larval skin, which have already been described. The 
length of the pupal life in my experiments was about ten days. 


THE ADULT 


The adults were kept in a good-sized breeding-cage with moist earth 
and some pieces of meat, both fresh and putrid, and were fed on crack- 
ers and milk, which they ate readily. They were not attracted to the 
flesh at any time, as other blow-flies are, and preferred the crackers 
and milk for food. It is evident, therefore, that the adults as well as 
the larvae are quite different in their habit from the commoner Calli- 
phorinae. 

Both Protocaliiphora azurea and P. chrysorrhea, which is closely 
related to it in structure and habits, are recorded by collectors and 
dipterologists as “rare” or “very rare,’ and specimens are found only 
in the larger museums and collections. I am inclined to think, however, 
that they are not so rare as is generally supposed, but that the adults 
are peculiar in their habits, flight, etc., and for this reason are rarely 


COUTANT—BLOOD-SUCKING MUSCID LARVA 145 


taken. From the habits of the larvae we would scarcely expect to find 
the adults around dung-heaps, decaying flesh, and similar places where 
the Calliphorinae are usually sought for. Few collectors, I imagine, 
have taken insects very often from the zone of air from fifty to one 
hundred feet above the ground, in the woods; yet from the habits of 
the larvae, this is where we would naturally expect that the adults 
would occur. And the contents of birds’ nests have not been studied to 
any appreciable extent from an entomological point of view. It seems 
probable, therefore, that they may be fairly common in spite of the 
few times they have been taken. 

Protocalliphora azurea has been reported from two or three places 
in France and a few places in Germany and Italy, and Walker reports 
one specimen in the British museum collection. In North America 
Hough declares the species “very rare.” Mr. C. W. Johnson has kindly 
noted for me, however, that there are three specimens in the collection 
of the Boston Society of Natural History, all taken in New England 
within the past few years. 

In its parasitism the species is not limited to a single host but it 
seems to occur more frequently among the birds which build more 
protected and stable nests, as in boxes of earth, etc. 

The species was first described by Fallen in 1816 under the name 
Musca azurea. Meigen listed it under the same name in Systematische 
Beschreibung. In 1845 Dufour, on the authority of Macquart, gave the 
species which he had reared the name Lucilia dispar. Schiner in Fauna 
Austriaca described Fallen’s species as Calliphora azurea and remarked 
that after comparing Dufour’s specimens he determined that Lucilia 
dispar is a synonym of Calliphora azurea. Rondani classified the 
species azurea as belonging to the genus Pollenia. Finally, Hough in 
dividing up the North American genera of Calliphorinae created a new 
genus, Protocalliphora, and takes as the type species the one under 
present consideration, the Musca agurea of Fallen. Two years later 
Hendel, unaware of Hough’s work, recognized the same differences and 
erected the genus Avihospita. The latter therefore falls as a direct 
synonym of Protocalliphora. 

Since the species has not been taken often, and since no very 
detailed description of the adult is available, I offer the following 
additions to the specific characters which other authors have givens 
size, 7.6 to 10.0 mm.; head, in the female, twice as broad as long, and 
as broad as the thorax and abdomen (from 2.5 to 3.0 mm.). The 
second segment of antennae is reddish-yellow with large black hairs; 
third segment, including the arista, black. (Hough states that the 
antennae are black, without noting that the second segment is always 
brown or yellow). The median half of front, from vertex to antennary 


146 THE JOURNAL OF PARASTTOLOGY 


fossa, is clothed with soft short black hairs, giving it a downy appear- 
ance; each lateral quarter of front is scaled with comparatively large 
white scales. The cheeks (bucca) are metallic blue, with a rather 
sparse, coarse black beard ; palpi are moderate-long, reaching to the oral 
margin, and reddish-yellow in color throughout (sometimes quite a 
dark brown) ; they are clothed with black hairs which are quite long 
towards the apex. 

The chaetotaxy of the head is as follows; ocellar pair of macro- 
chaetae, mid-way in each ventral side of the ocellar triangle present, 
besides several microchaetae within the triangle; two pairs of verticals 
present, the inner pair larger, convergent, and decussating near the 
tips, the outer pair divergent; in front of, and between the verticals, 
is a pre-vertical bristle. There are two pairs of fronto-orbitals. The 


Fig. 6—Dorsum of thorax in adult. X 10. (adc) anterior dorso-centrals; 
(aidc) anterior inner dorso centrals; (aia) anterior intra alar; (dsc) dorsal 
scutellar; (h) humerals; (ia) intra alars; (pdc) posterior dorso centrals; 
(pidc) posterior inner dorso centrals; (pf) post humerals; (pa) postalars; 
(pr ap) pre-apical; (ps) pre-sutral; (sa) supra alars; (sc b) scutellar bridge; 
(sq) lower squama-squamula thoracalis; (u sq) upper squama-squamula alaris. 


row of frontal bristles is fairly constant and well-developed, usually 
nine, sometimes eight or ten. I have no specimens of the male. 

The thorax is a lustrous metallic steel blue color, throughout. On 
the dorsum, however, this blue color is overlaid by a fine whitish bloom, 
which covers most of the mesonotum, except in definite areas where the 
blue shows through. These areas are indicated on the drawing of the 
thorax (Fig. 6). The squamae are prominent, whitish-colored, and coy- 
ered with a very fine down on both surfaces, with a fringe of longer 
hairs around the edge. The legs are black; the halteres white. The 


COUTANT—BLOOD-SUCKING MUSCID LARVA 147 


wings when at rest are folded over the abdomen, their outer (anterior) 
margins parallel to the body. The wing venation is very constant in 
the smallest details, and is as described in other works. 

The position and numbers of the various macrochaetae which are 
constant on the thorax in this species may be seen from the accom- 
panying drawings (Figs. 6, 7). They are as follows: on the dorsum, the 
anterior inner dorso-centrals (acrostichals), composed of four well- 
developed macrochaetae (a idc, in figures) ; the posterior inner dorso- 
centrals (p idc), also containing four bristles, each present in all the 
specimens I have examined, although they vary somewhat in size, and 
frequently in position (the second and third posteriors most often). 
This differs from Hough’s observation that the posterior acrostichals 
vary in number or are poorly developed in Protocalliphora. The ante- 
rior dorso-central bristles (@ dc) are three in number, the posterior 


Fig. 7—Lateral aspect of thorax in adult. X 10. (h) halteres; (hc) 
humeral callus; (mp) metapleura; (7) notopleur; (po) postalar callus; (pp) 
propleura; (fr) prealar callus; (s) scutellum; (sp) spiracle; (ts) transverse 
suture. 


(p dc) four; the intra alars are three in number (ia). A single small 
anterior intra alar (a ia) is present, three to five supra alars (sa), and 
one presutural (pf s). There are three posthumerals (p /), five 
humerals (/1), and two well-developed post alars (pa). The scutellum 
has a peripheral row of bristles which varies in number from six to 
ten (three to five on each side) ; there is sometimes an odd number 
of them, due to the presence of a macrochaeta on one side without a 
mate on the opposite side. ‘These bristles have each been given an 
individual name by Girschner, but since their development seems more 
or less irregular and inconstant, I simply call them the peripheral row. 
In addition to these I have found two pairs of bristles on the dorsal 


148 THE: JOURNAL . OF - PARASITOLOGY 


surface of the scutellum. The dorsal scutellar pair (d sc) (so-called 
by Girschner), are not in line with the inner dorso-central row but 
laterad of it. The pre-apical scutellars (pr ap) are quite small, but 
are markedly different at the insertion from the microchaetae. Both 
pairs are present in all of my specimens. 

Not having any male specimens of Protocalliphora azurea, nor any 
specimens of P. chrysorrhea, to examine, I can not tell whether this 
arrangement of bristles on the scutellum is a specific character or not. 
But I strongly suspect from the work of Girschner and from a com- 
parative study of these bristles in Luciliar, Phormia and Calliphora, 
that it is a generic rather than a specific or sex character. 

There are two macrochaetae on the notopleura; the mesopleurals 
are usually seven in a vertical row, the second from above sometimes 
rather undersized. In two cases there are eight, the extra one being in 


TABLE OF MICROCHAETAE ON THE NOTOPLEURA OF PROTOCALLIPHORA AZUREA 


Bristles Before the Bristles Behind the 
Specimen No. Posterior Macrochaeta Posterior Macrochaeta 

toe Get sideyin. setae cr 8 6 

RB Gicht side)... non 8 i 
Dale, ist eA Ma ee es 8 5 

Re Ree tee as ee 8 4 
Ya aie ei 05 ion oe ia ae ee 7 3 

1B ume Anes apa Mata eee 16 4 
7A) (ide i et Agee Sok oh Seton eter 10 5 

Reo KE eRe 8 4 
Gio | Daan prac ae ve, Aiba eons aoe 8 5 

ea (destroyed)ernrera: a 
(Ciel bso Rees Vike en as ee 7 3 

{GY Serer aM od Crete a8 5 3 


the space before the last bristle. The pteropleura is quite bare save 
in the region under the wing-base, where there is a row of from four 
to six rather small macrochaetae. The hypopleural row is composed 
of seven well-developed and constant macrochaetae. On the dorsal 
margin of the sternopleura there are three bristles. The long micro- 
chaetae on the sides of the sternopleura gradually become more dense 
ventrad, and the individual hairs also become much thicker, until they 
must be called macrochaetae. They are too numerous to be readily 
counted. There are a number of macrochaetae on each coxa. Near the 
cephalic margin of the fused mesopleura and sternopleura are four 
macrochaetae, arranged as indicated in the figure. Two of them are 
much smaller than the other two. More cephalad still, between the 
propleura and the front coxa are two other bristles. 


COUTANT—BLOOD-SUCKING MUSCID LARVA 149 


Since the work of Osten-Sacken the importance of chaetotaxy in 
the classification of certain groups of the Diptera has been well recog- 
nized, and it has been suggested that since setae occur in every form 
and size between the macrochaetae and the microchaetae, there must 
also be a very definite microchaetotaxy in the various genera and 
species. As a preliminary record on this point, I have counted the 
microchaetae on the notopleurae of each of my specimens. 

Those anterior to the posterior macrochaetae are fairly constant 
in number, though there seems to be no very regular arrangement. 
There are usually eight, but sometimes six to ten. Those behind the 
posterior bristle gradually taper off to such minute hairs as are scarcely 
visible, and vary irregularly in number (from three to seven). 

For comparison with other genera I have counted specimens of 
Lucilia sericata and L. caesar, of Calliphora erythrocephala, C. viri- 
descens, and C. vomitoria, of Protophormia terrae-novae, and of Phor- 
mia regina. The exact number of microchaetae is not the same in all 
specimens of the different genera, nor on the same sides of the same 
specimen. Nevertheless there is in each genus a general range within 
which all members fall, and this is so constant that I am convinced that 
it is at least of generic significance. Thus, in Phormia the number 
ranges from thirteen to nineteen, the majority having sixteen; in 
Lucilia there are from fourteen to twenty-five, the majority having 
twenty plus; in Protophormia the range is from fifteen to thirty, the 
majority grouping around twenty-six; while in Calliphora there are a 
great many more, the number running from thirty to seventy-five, with 
the majority having a number in the vicinity of forty. 

The abdomen has the typical muscid shape. It extends 3.5 to 4.0 
mm. beyond the end of the scutellum, only four segments showing in 
the dorsal aspect. The color of the abdomen in the females is a metallic 
blue-green on the first three segments, the tip being a lighter golden 
green. It is slightly pollinose (less so than the thorax) so that in some 
aspects it has a whitish appearance. It is covered by rather long black 
microchaetae, which on the caudal margin of the last two segments 
become enlarged and thickened and are practically macrochaetae. 


SUMMARY 

Protocaliiphora agzurea, a Muscid larva, occurs as a normal blood- 
sucking parasite of nesting birds, with fatal results in some cases. 
This represents the extreme specialization of these larvae towards 
parasitism; many intermediate stages are also represented in other 
members of the group. 

The structure of the larva and of the pupa are described in detail, 
and also the habits and distribution of the adult. The anatomy of 
the adult is discussed with especial emphasis on the distribution of the 
bristles as this is very regular and of marked significance in taxonomy. 


150 THE JOURNAL OF PARASITOLOGY 


REFERENCES CITED 


Du Buysson, R. 1912. Essai sur les Dipterants vulnérants du Venezuela. 
Paris, tesco 

Dufour, Leon. 1846. Historie des metamorphoses de la Lucilia dispar. 
Ann. Soc. Ent. France, ser. 2, 3: 205. 

Girschner, E. 1901. Ueber eine neue Tachinide und die Scutellarbeborstung 
der Musciden. Wien. Ent. Zeit., 20: 69. 

Henshaw, H. W. 1908. A Parasitic Fly Injurious to our Native Birds. 
The Auk, 25: 87. 

Hewitt, C. G. 1908. The Structure, Development, and Bionomics of 
the Housefly. Part II. The Breeding Habits, Development and the Anatomy 
of the Larva. Quar. Jour. Micr. Sci., 52: 495. 

Hough, G. de N. 1899. Some North American Genera of the Dipterous 
Group Calliphorinae (Girschner). Ent. News, 10: 62-66. A Synopsis of the 
Calliphorinae of the United States. Zool. Bull., 2: 283-290. 

_ Meigen, J. W. 1826. Systematische beschreibung der bekannten europaischen 
zweifliigeligen Insekten, 5: 63. 

Rodhain, J. 1914. Sur une larve de Muscinae vivant dans le nid de Passer 
griseus au Congo, Revue Zool. Afric. Brussels, 3: 213. 

Rouband, E. 1913. Recherches sur les Auchméromyies. Calliphorines a 
larves sucenses de sang de l’Afrique tropicale. Bull. sci. France et Belg., 
ser. 7, 47: 105-202. 


EXPERIMENTS ON CYSTICERCI OF TAENIA PISIFORMIS 
BLOCH AND OF TZENIA SERIALIS GERVAIS * 


James E. ACKERT 
Kansas State Agricultural College. 


The life histories of the dog tapeworms, Tenia pisiformis Bloch 
and Tenia serialis Gervais, are understood, but to what extent other 
vertebrates than the usual hosts constitute suitable environments for 
the development of the ingested cysts of these tapeworms is a question 
that deserves further consideration. This question, together with the 
custom of feeding to chickens the common wild rabbit (Lepus floridans 
mearnst Allen) and the hare or jack-rabbit (Lepus campestrus 
Bachm.), led the writer to carry on some experiments to ascertain 
whether 7. pisiformis and T. serialis will develop in fowls. 

As is known, the common wild rabbit or cottontail is the inter- 
mediate host of T. pisiformis. The larval form (Cysticercus ptsi- 
formis Zeder) develops in the peritoneal cavity, omentum, and mesen- 
tery. In eastern Kansas a high percentage of the cottontails is infected 
with these cysticerci; Scott (1913) examined sixty-four cottontails 
taken in this vicinity and found this cyst in nearly 84 per cent. of them. 
All of the rabbits used in these experiments contain Cysticercus pisi- 
forms. 

The chickens used in the experiments were kept from the time of 
hatching in a fly-proof enclosure and fed upon food free from animal 
tissues. In the first experiment, the cysticerci were removed from the 
omenta and mesenteries of the rabbits and fed at once to the fowls, 
care being taken to prevent injury to the cysts before they were swal- 
lowed. Cysticercus pisiformis was fed to three chickens. To the first, 
five on July 8 and sixteen on July 10. To the second, five on July 8 
and ten on July 10. To the third, twenty-three on July 13. Two 
months later (September 5, 8 and 12, respectively) an examination of 
these chickens failed to reveal a tapeworm. 

It is known that the intermediate host of T. serialis is the hare or 
jack-rabbit, although the cottontail occasionally harbors the multiple 
cyst, Coenurus serialis Gervais, of this cestode. The seat of infection 
is in the connective tissue, particularly intermuscular, of the head, 
neck, thorax, loins and limbs. 


* Contribution No. 6 from the Zoological Laboratory, Kansas State Agri- 
cultural College. Experiments by aid of Adams fund. 


152 THE JOURNAL OF PARASITOLOGY 


In the second experiment, the multiple cysts (with one exception) 
were not removed from the loins of the hares until the latter had been 
dead twenty-four hours. During this time, however, the lowest tem- 
perature of the surrounding air was approximately 40° F. In all prob- 
ability, the cysts were not subjected to a temperature sufficiently low 
to impair their vitality, for Ransom (1914) has demonstrated that a 
prolonged (six days) temperature of 15° F. is required to kill Cysti- 
cercus bovis in beef. Nor is it at all likely that the length of time was 
sufficient to seriously lessen the vitality of the cysticerci, as Baillet 
(1863) has found that Cysticercus pisiformis maintains its vitality for 
as many as eight days after it has been exposed to the air. Multiple 
cysts were removed from the hares and fed to three chickens. To the 
first, one on July 8 (immediately after the death of the hare). To the 
second, twenty-four on December 12. To the third, twenty-two on 
December 12. On September 5, January 16 and 30, respectively, these 
chickens were examined and in no case was a tapeworm found. 

In looking up the literature on these two cestodes, the writer was 
surprised to find so many records of attempts to infect mammals with 
the cysticerci of these tapeworms. Moniez (1896) fed cysticerci of 
T. serrata to two human volunteers and no tapeworm developed. In 
1898, Galli-Valerio swallowed six of these cysts without developing a 
tapeworm. Hall (1914) ingested three Cysticercus pisiformis from a 
freshly killed rabbit with no results. In 1913, Scott fed Cysticercus 
pisiformis to swine and in no case did a tapeworm develop. The fail- 
ure of attempts to infect swine, fowls and man with T. pisiformis 
indicates that this tapeworm is somewhat specialized with reference to 
its host. 

So far as the writer has been able to ascertain, T. serialis has not 
been reported from man. Galli-Valerio (1909) ingested two living 
scolices from Coenurus serialis without experiencing any discomfort 
and without becoming infected. Hall (1910) failed to develop a tape- 
worm after swallowing three living scolices from this cyst. Hence, it 
appears that 7. serialis cannot develop in man. The attempt of Thomas 
to infect cats and ferrets by feeding to them the larve of T. serialis 
failed, according to Hall (1910). And Scott (1913) on feeding these 
cysticerci to pigs was likewise unable to infect them. 


SUMMARY 


From the experiments reported in this paper it appears that 
T. pisiformis and T. serialis will not develop in fowls. Previous inves- 
tigations show that 7. pisiformis fails to develop in man and in swine, 
and that T. serialis does not develop in man, swine, cat and ferret. 


ACKERT—EXPERIMENTS IN CYSTICERCI 153 


REFERENCES 

Baillet, C. 1863. Recherches sur un cystique polycéphale du lapin et sur le 
ver qui résulte de sa transformation dans l’intestin du chien. Mem. acad. imp. 
de Toulouse, 6 s., 1: 452-482. 

Galli-Valerio, B. 1898. Notes helminthologiques et bacteriologiques. 
Centralbl. f. Bakteriol., 1 Abt., 23: 939-944. 1909. Notes de parasitologie et de 
technique parasitologique. Centralbl. f. Bakteriol., 1 Abt., Orig., 51: 538-545. 

Hall, M. C. 1910. The Gid Parasite and Allied Species of the Cestode 
Genus Multiceps. Bur. An. Ind., Bull. 125; 68 pp. 1914. Experimental Inges- 
tion by Man of Cysticerci of Carnivore Tapeworms. Jour. Parasit., 1: 42-44. 

Moniez, R. 1896. Traité de parasitologie animal et végétale. Paris, 680 pp. 

Ransom, B. H. 1914. The Destruction of the Vitality of the Cysticercus 
Bovis by Freezing. Jour. Parasit., 1: 5-9. 

Scott, J. W. 1913. The Viability of Certain Cysticerci in Pigs and in Young 
Dogs. Science, n. s., 37: 263. 


SOCIETY PROCEEDINGS 


THE HELMINTHOLOGICAL SOCIETY OF WASHINGTON 


The twenty-second regular meeting of the society was held at the residence 
of Mr. Hall on October 29, Mr. Hall acting as host. The evening was devoted 
to an informal discussion of zoological and medical topics. 

Maurice C. Hatt, Secretary. 

The twenty-third regular meeting of the society was held at the residence 
of Dr. Pfender on December 17, 1914, Dr. Pfender acting as host and Dr. Stiles 
as chairman. 

Dr. Sweet was elected a foreign corresponding member of the society. 

Dr. Ransom presented a paper by Ransom and Hall, entitled The Life His- 
tory of Gongylonema scutatum. Encysted larval nematodes were found by the 
senior author in the body cavity of Aphodius femoralis, A. granarius, A. fime- 
tarius, and Onthophagus hecate at Bethesda, Maryland. Certain morphological 
characters suggested the possibility that they were the larvae of Gongylonema. 
Furthermore, dissections of larval beetles of these and related species disclosed 
the presence of free nematode embryos which agreed exactly with embryos 
taken from the eggs of Gongylonema scutatum. Nematode larvae similar to 
those discovered at Bethesda were found in Aphodius coloradensis, A. vittatus, 
and A. granarius in El Paso County, Colorado. The feeding of these larvae 
to sheep resulted in infestations with G. scutatum. Eggs of G. scutatum were 
fed to Aphodius spp. and to Croton bugs, Ectobia germanica. In the course 
of two days free embryos of G. scutatum were recovered from the insects; later, 
other stages were found, and at the end of a month the final encysted larval 
stage was present. Small dung beetles belonging to the genus Aphodius, appear 
to be the most common hosts. 

Dr. Cobb presented a very unusual note, dealing with a new species of free- 
living’ nematode, which has been made the subject of some experiments and 
observations arising from the presence in its intestinal cells of the substance 
rhabditin, described in a former paper presented before the society. It has 
been found possible to rear several successive generations of this nematode on 
agar made up with only those traces of nitrogen contained in tap water and 
“pure” agar. Simultaneously it has been determined that the nematode is aero- 
phagous, and Dr. Cobb exhibited to the society a preparation in which the liv- 
ing nematode was shown actively ingesting air. The nematode can take in its 
own volume of air in the course of an hour or two, the air passing into the 
esophagus being visible as bubbles taken in at the surface of the nutrient 
medium, to which the nematodes resort from time to time. This ingested air 
may be followed as it passes quickly through the esophagus and as far as the 
anterior portion of the intestine where it is rapidly and completely absorbed, 
each bubble of air as it reaches the intestine requiring only two to three seconds 
for its absorption. The obvious conclusion suggested by the development of 
several generations of this nematode on a “nitrogen-free” medium and its habit 
of swallowing air, is that the nematode, among other things, has the power 
of fixing atmospheric nitrogen. The cultures were not free from bacterial con- 
tamination, though the contamination was not heavy; it was possible by frequent 
transfers of the nematode to keep them in relatively pure media. The most 
significant feature of the observations is the undoubted ingestion and absorp- 
tion of relatively large quantities of nitrogen. The development of the nematode 
under the conditions named does not appear to reduce very materially the 
amount of rhabditin. 


HELMINTHOLOGICAL SOCIETY OF WASHINGTON 155 


Dr. Cobb also exhibited to the society some mounts of free-living nematodes, 
showing elaborate structures and a remarkable trigger-like process anterior to 
the cloacal aperture in the male. 

Mr. Foster presented a paper entitled The Use of Vermifuges in the Treat- 
ment of Swine. He finds oleum chenopodii very satisfactory, comparing very 
favorably with santonin. Coal tar creosote was not found to be satisfactory. 

Mr. Hall presented a paper entitled A Note on Syngamus laryngeus from 
Cattle and Carabao in the Philippine Islands. This paper records the parasite 
for the first time since its description by Railliet from Annam. 

Mr. Hall also presented a note on the ingestion of ascarids by man. An 
employee of one of the big packing houses in Chicago, a so-called “Polack,” 
working at the gutting bench in the hog room, was in the habit, according to 
Dr. Woodruff of the U. S. Bureau of Animal Industry, of slitting open the 
intestines of hogs, where they could be seen distended with Ascaris suum, tak- 
ing a handful of these worms and eating them down in several bites. Dr. 
Woodruff states that the man showed no visible evidence of ill effects from 
this habit, which is rather remarkable, as, aside from the esthetic repugnance 
which would be sufficient to make the average person sick, ascarids have cer- 
tain toxins which often affect helminthologists unpleasantly on merely work- 
ing with these worms, some persons developing a hypersusceptibility which 
makes the presence of the worms in the same room intolerable. The case 
must be regarded as an individual idiosyncrasy, suggestive of mental defects, 
physiological disturbances, or some such pathological condition. In this con- 
nection it may be noted that all reports that the inhabitants of any section of 
Italy are in the habit of eating ligules have met with strong and indignant 
denials on the part of the Italian helminthologists. 

Dr. Stiles gave a talk on sanitary conditions in the southern United States, 
emphasizing the good effects to be anticipated in dealing with problems of this 
sort in a quiet, personal way and avoiding unpleasant, undesired, and unmerited 
newspaper notoriety. 

‘Dr. Pfender gave a very instructive demonstration of the use of radiography, 
illustrating his points by stereoscopic radiographs and the use of the fluoroscope. 
Maurice C. Hatt, Secretary. 

The twenty-fourth regular meeting of the society was held at the residence 
of Mr. Chambers on Jan. 28, 1915, Mr. Chambers acting as host and Dr. Cobb 
as chairman. 

Dr. Stiles gave an extended discussion of sanitary conditions in the South, 
with especial reference to the respective merits of the pit privy and the so-called 
“umbrella privy”. 

Mr. Chambers exhibited a figure of a new free-living nematode from Panama, 
the worm being provided with three jaws, each of which is armed with three 
rows of retrorse teeth. 

Dr. Cobb exhibited a Baker collapsible microscope. 

The secretary presented a note by Mr. Crawley in regard to the protozoa 
found in the cloaca of frogs, with special reference to variations in Opalina. 

Maurice C. Hatt, Secretary. 


BOOK REVIEWS 


A REVISION OF THE CESTODE FAMILY PROTEOCEPHALIDAF. By George R. LaRue. 
Illinois Biological Monographs, Vol. I, Nos. 1 and 2. Urbana, Illinois. 1914. 
350 pp., 16 plates. 

This work is the most complete and comprehensive yet published on the 
proteocephalid tapeworms. The author has gathered together and carefully 
compiled the observations of other investigators on this group, and with this 
compilation he has combined in monographic form a large mass of data col- 
lected from his own studies on the various species of the family. The Proteo- 
cephalidae occur in fresh-water fishes, reptiles and amphibia, and comprise 
five genera and about fifty species. Excepting the genera Acanthotaenia and 
Corallobothrium which are only touched upon incidentally, the author has covered 
the various species not only of this group but also those belonging in the 
genus Monticellia LaRue, 1911 (Tetracotylus Monticelli, renamed), which he 
separates from the Proteocephalidae as the type of a nearly related but distinct 
family, Monticellidae. The morphology, which is illustrated with 199 figures, 
synonymy, host records, ete., are fully discussed for each species. The por- 
tion of the work pertaining to general questions such as geographical distribu- 
tion, host relationships, etc., is of special interest to economic zoologists, because 
as already pointed out by Ward (1910) valuable clues in clearing up certain 
problems in the biology of food fishes are likely to be picked up from a knowl- 
edge of fish parasites. 


THE PROPHYLAXIS OF MALARIA WITH SPECIAL REFERENCE TO THE MILITARY 
Service. C. F. Craig. War Department: Office of the Surgeon-General. 
Bulletin No. 6. Government Printing Office, Washington, 1914. 115 pp. 
12 plates. ’ 
This pamphlet, published for the information of medical officers in the army, 

gives a careful and clearly written synopsis of present knowledge on the organ- 

ism of malaria and its transmitting agents. The work opens with a discussion 
of the methods for studying both living and preserved material, the structure, 
life history and habits of the various species of Plasmodium occurring in man 
and of the types of Anopheline mosquitoes that transmit them. Further chapters 

deal in extenso with the prophylactic methods and their application to the mili- 

tary service. At the close is given a bibliography of important references which 

though complete contains some errors and irregularities of citation that may 
embarrass inexperienced students. 


Tue ANALES pE Zootocia APLICADA, recently established in Chile is devoted 
to the biological and systematic study of animal parasites (Arthropoda, Vermes, 
and Protozoa) of the neotropical region. The editor, Professor Carlos E. 
Porter, Director of the Zoological Museum at Santiago, is known for extensive 
and valuable work in research and as editor of the Revista Chilena de Historia 
Natural. 


Tue Parasitic AMOEBAE OF MAN. By Charles F. Craig, M.D., Captain Medical 
Corps, U. S. A., Pp. x + 253, thirty figures. Philadelphia: J. B. Lippincott 
Co., 1914. 

In his preface the author emphasizes the desirability of a work of this nature, 
owing to the great importance of amebic infections of the intestine and liver 
in man, and to the great frequency with which such infections are met both 
in our tropical possessions and in certain parts of this country. 

The first chapter gives a historical review of the important investigations 
relating to amebae found in man. In the second chapter the morphology and 


BOOK REVIEWS 157 


biology of amebae, and the methods of reproduction are discussed with a brief 
historical review of the resistance of amebae to physical and chemical agencies. 
In a discussion of the classification and nomenclature of the organisms Craig 
points out that a pathogenic and non-pathogenic species of ameba’ in man 
were first demonstrated by American investigators rather by Jiirgens and 
Schaudinn. It is true that from a zoological standpoint Schaudinn gave the 
most complete description of two species of amebae found in the intestine in 
man, but a number of his observations regarding one species are unconfirmed. 
As Craig points out, however, Schaudinn’s classification has been generally 
accepted by zoologists, although few have observed the morphological char- 
acteristics of Entamoeba histolytica he described. 

Craig gives complete account of the technic of examination of amebae in 
the fresh state and the methods to be employed in fixing and staining them. 
The method deyised by Wolbach for the hardening of tissues and staining of 
trypanosomes in sections, which is also an excellent one for staining amebae 
in sections, might have been added. The cultivation of these organisms is then 
discussed and the fact pointed out that all amebae which have been culti- 
vated upon artificial media are free living species and of no etiological signifi- 
cance in dysentery, whereas the parasitic amebae have not been cultivated. 
In the sixth chapter the distribution, morphology, reproduction, life cycle, 
attempts at cultivation, and relation to disease of the different species of human 
intestinal amebae are considered very exhaustively, and the characteristics of 
the different species illustrated by plates and figures. The differential diagnosis 
of Entamoeba coli, Entamoeba histolytica, and Entamoeba tetragena, is also 
discussed and a table given showing the differential features. The author 
emphasizes rightly that a differential diagnosis of these species does not rest 
upon the presence of a single morphological feature, but should only be made 
after a careful consideration of all morphological data, as well as the life cycle 
of the organisms investigated. Craig apparently regards Entamoeba histolytica 
and Entamoeba tetragena as different species, whereas Walker believes tetragena 
is a variety of histolytica. 


In discussing the amebae of the mouth, Craig points out that the distribu- 
tion of the common species, Entamoeba buccalis, is world-wide, and that while 
it is sometimes found in carious teeth, there is no experimental evidence con- 
necting it with disease. He shows that it may be frequently demonstrated in 
material scraped from the roots of perfectly normal teeth, and that so far as- the 
evidence goes, it must be regarded as only a secondary invader of the tissues. 
It is very doubtful if this form has anything to do with caries of the teeth. 
The other amebae found in the mouth he agrees with Prowazek are identical 
with Entamoeba buccalis. Brief reference is made to the occurrence of amebae 
in the genito-urinary tract, in exudations and abscesses, and in the lungs. 


The book is well printed, is written in an interesting manner, and consti- 
tutes an important addition to the literature on this subject. 


The Government Bureau of Microbiology (New South Wales) has a 
division devoted to animal parasites. Its Third Report includes several impor- 
tant notes by J. Burton Cleland. Coccidia (probably Eimeria stiedae), reported 
for the first time in Australian cattle were found in moderate numbers in the 
caecum of a cow. More than half the house sparrows examined during 1911 
and 1912 were found to be infected with Jsospora lacazei (Labbe), known in 
England from various passerine birds. An attempt to introduce this parasite 
experimentally into chickens was unsuccessful. 


The most extended communication is a study of the life history of 
Onchocerca gibsom. These worm-nests in cattle which had never left Milson’s 
Island gave localized conditions for study. The distribution of the parasite 


158 THE JOURNAL OF PARASITOLOGY 


and the finding of living embryos in subcutaneous situations suggests an insect 
vector. Either the stable fly (Stomoxys calcitrans), or a mosquito (Culicelsa 
vigalax) may be the carrier. Experiments showed that Stomoxys calcitrans 
can ingest living embryos from opened worm-nests and these embryos remain 
alive and active in its alimentary canal as long as three days. An attempt to 
infect a calf through Stomoxys calcitrans which had ingested living embryos 
was not successful. Calves could not be infected by embryos taken with milk 
or injected subcutaneously. The position of worm-nests and free embryos 
makes it probable that infection first occurs in the lower extremities and that 
the embryos migrate along the lymph channels. 


NOTES 


Doctor RicHArD P. Stronc, Professor of Tropical Diseases in the Harvard 
Medical School, and a member of the Editorial Board of the JourNAL, has just 
left for Servia as chairman of the Sanitary Commission sent by the American 
Red Cross to aid in the control and suppression of typhus, cholera and other 
epidemic diseases. Doctor Strong’s admirable record during the terrible epi- 
demic of pneumonic plague in Manchuria in 1911 makes him an ideal leader 
for this, which Surgeon General Gorgas believes the most important sanitary 
work in years. 

ProFEssor Doctor A. Looss, the well-known helminthologist, who was for- 
merly pathologist in the Medical School at Cairo, Egypt, retired from that 
position with the outbreak of the war. He is now in Germany engaged in 
scientific work, and wishes to announce his address for the future as Stephans- 
trasse 18, Leipzig. 


The Journal of Parasitology 


Volume 1 JUNE, 1915 Number 4 


THE PARASITE OF ORAL ENDAMEBIASIS, ENDAMEBA 
GUINGT Aer Ss \(GROS)'* 


ALLEN J. SMITH AND M. T. Barrett 


The pathogenic importance of the endamebae of the human mouth, 
which formerly were held as innocuous and were but scantily con- 
sidered by pathologists, has been urged by the writers and others in 
a series of articles published within the past five or six months.t 
According to this view the writers regard these parasites as 
either directly causative of a large class of gingival and alveolar 
pyorrheas or as important members of a symbiotic chain with 
one or other of the numerous associated vegetable micro-organ- 
isms, in the production of these lesions. They find these enda- 
mebae also in the tonsils, in cases of chronic cryptal inflammation, 
often with tonsillar enlargement; and are disposed to regard them as 
concerned in the production or maintenance of such inflammatory 
changes of these organs; and moreover, believe that a long series of 
systemic complications of Riggs’ disease and tonsillitis are due in 
some part to these parasites. Proof of the pathogenic importance of 
the endamebae in Riggs’ disease rests upon their almost constant 
presence in the suppurating pockets of pyorrhea, and the prompt 
removal of both suppuration and of the endamebae when emetin, 
a proved amebicide but of low bactericidal value, is administered 
locally or generally. The authors hold that an overwhelmingly large 
group of cases of pyorrhea in which these endamebae are met should 
be segregated under the name “endamebic pyorrhea,” in the same 
way that dysenteries in which dysenteric endamebae are met are 
known as “endamebic dysentery”; but reserve a small series of pyor- 


* From the Laboratories of Pathology of the Medical School of the Univer- 
ity of Pennsylvania, Philadelphia, Pa. 

Bs eo at Christmas Meeting of American Society of Bacteriologists, 
14. 

1. Preliminary report by Barrett: Dental Cosmos, August, 1914. See also 
Smith: Dental Cosmos, September, 1914. Bass and Johns: New Orleans Med. 
and Surg. Jour., November, 1914. Smith, Middleton and Barrett: Jour. Amer. 
Med. Assn., November 14, 1914. Barrett: Dental Cosmos, December, 1914. Cf. 
Chiavaro: Abst., Dental Cosmos, September, 1914. 


160 THE JOURNAL OF PARASITOLOGY 


rhea cases which cannot be included in this class. In attributing 
influence of these protozoa in the production of systemic complica- 
tions the writers follow the general lines of argument as to the influ- 
ence of “oral sepsis’ of Hunter and others, merely emphasizing the 
endamebae as essentially involved because in their experience in a 
number of cases such complicating conditions have yielded, along 
with the oral lesions, to the use of emetin. Among such complica- 
tions they include various chronic and recurrent arthritides (of the 
type of arthritis deformans), certain obscure anemias (as some of 
the splenic anemias and picked cases of pernicious anemia), functional 
and catarrhal disturbances of the gastro-intestinal canal, and prob- 
ably, too, cases of degeneration of parenchymatous organs (as kidney 
and liver), an undefined group of serous inflammations (as of the 
heart), and perhaps, also, certain chronic functional nervous dis- 
turbances (neuralgias, etc.). 

If no more of this comprehensive list of disturbances prove ulti- 
mately to be caused by these parasites than the local peridental sup- 
purations and, perhaps, chronic cryptal tonsillitis, a careful systematic 
consideration of the parasites in question would be amply justified; 
and it is from this standpoint that the present discussion is pre- 
sented, in an attempt to coordinate the amebiform organisms described 
by various observers as parasites of the human mouth and to com- 
pare them with other and better known forms of endamebae.? 

In 1849 Gros* in a comprehensive article entitled “Fragments 
d’Helminthologie et de Physiologie microscopique,” announced his 
discovery of an amebic parasite in the human mouth and published 
therewith drawings of the organism. There is little of importance, 
other than the announcement of the observation, in his text; but as 
the drawings are of importance, both are here reproduced (Fig. 1). 


AMOEBEA GENGIVALIS 


Au milieu des productions du tartre des dents, on voit des vibrios, une sorte 
de végétation qui est quelquefois trés réguliere; mais on n’avait pas encore 
mentionné les vésicules que nous avons représentées, Pl. VI, C. Ces vésicules 
ont un mouvement si lent et si obscur qu’il faut en étre averti pour remarque 
qu’elles prennent toutes les formes, par une extension et contraction amoebéenne, 
laissent toujours voir a l’intérieur des globules qui semblent se déplacer un peu, 
et étre l’analogue de ce que nous connaissons chez de certains infusoires so1- 
disant polygastriques. Leur origine, leur role et leur fini sont ignorés. Elles 
se trouvent surtout a la face interne des dents. Est-ce encore une génération 
spontanée ? 


2. This spelling is adopted by the writers instead of entameba, proposed by 
Casigrandi and Barbagallo in 1897 (Ann. d’Igenie, vol. 7, p. 103), because in 
1879, Joseph Leidy (Proc. Acad. Nat. Sci., Philadelphia, vol. 31, p. 204), then 
professor of anatomy in this school, proposed the generic name endameba for 
a parasitic ameba of the cockroach (endameba blattac). Aside from a feeling 
of personal loyalty to Dr. Leidy the writers are impelled by the rules of pri- 
ority to adopt his nomenclature. 

3. Gros: Bull. Soc. imp. de nat. de Moscow, Vol. 22, No. 2, pp. 549-573. 


THE PARASITE OF ORAL ENDAMEBIASIS | 161 


No one can look upon the drawings of Gros and fail to be con- 
vinced that he actually found amebae; and, if the size of the globules 
contained within them be accepted as that of the globular remnants 
of undigested leukocytic nuclei such as are commonly found in mouth 
endamebae, that the organisms were of about 0.025 to 0.030 mm. in 
diameter ; that they threw out broad, rounded lobose pseudopodia and 
that in these pseudopods and at their bases a clear hyaline ectosarc 
was distinguished from a granular endosarc containing the coarse 
globular material. It may be accepted that these points, together with 
the habitat of the organisms upon the dental surface and in soft tartars 
were established by Gros. 

In 1862, Steinberg,* in his thesis before the University of Kiev, 
in which he gives the details of his observations upon the living forms 
he encountered in the substantia mollis alba (soft tartar and refuse) 
about the teeth, probably refers, among other animal and vegetable 
organisms, to the same ameba announced by Gros thirteen years 
previously ; but it is doubtful whether he had knowledge of the pub- 
lication by Gros. At least he makes no mention of it, and writes as 
if under the belief that he is discussing a personally discovered 
amebic parasite, to which he attaches the name amiba buccalis. 

The text is very curious but disappointing and there are no accom- 
panying illustrations. However, because the volume containing his 
observations is rare in medical libraries and because of the difficulty 
of dealing with the original Russian language, the writers present 
the following translation, rendered for them by Dr. Fischelis of this 
city, of that part of the comprehensive article by Steinberg which 
concerns the matter in question: 


AMIBA BUCCALIS 


These organisms I met in various forms and sizes. Their characteristics 
are of a negative rather than of a positive character, in that they have no fixed 
size (this changing several times a minute); that they have no definite motile 
organelles (these being substituted by expansions or pseudopodia, appearing 
now here, now there, on different parts of the body); that they do not present 
a distinct direction of movement, as the pseudopodia by which they move appear 
at varying positions on the body and then retract again. The number of 
pseudopods is not fixed, now none, sometimes one, two, three, four and more; 
a change in the number of extensions occurring in the individual in a compara- 
tively short time (one or two minutes). The shape of the pseudopodia in a 
given individual is not fixed, and their length is also variable. Granules are 
distributed within the body of the ameba and these do not retain any constant 
mutual relation, or to the individual itself or to the periphery of the ameba. I 
observed, however, a difference in the amebae seen on different days. While 
the size of the amebae in a given instance is constantly undergoing change, such 
change has its limitations; but it can be said that to-day, for example, the 
amebae observed are generally larger or smaller than those seen upon a previous 
day. Although the pseudopodia of a given ameba are in constant change, they 


4. Steinberg: Souremenaya meditsina, Kiev, 1862, Nos. 21-24. 


162 THE JOURNAL OF PARASITOLOGY. 


may in one instance be more obtuse, short and rounded off, and in another 
larger, less obtuse and not rounded, etc. The body of the ameba with all its 
variability, depending upon the instability of the pseudopods, preserves a more 
or less common character or peculiarity, hard to describe; but the experienced 
eye of the observer notices and recognizes this peculiarity. In a given ameba, for 
example, there are always pseudopods present; in another there are times when 
none are to be seen. In a word, the total summation of a series of characteristics 
which are individually of no importance enables the observer to conclude, for 
instance, that he has before him not one single type of amebae but various 
amebae. 

Having observed amebae in the soft white substance about the teeth and 
those in various infusions, I was able to convince myself that with all their 
indefiniteness of outlines and size there are certain features characterizing all 
amebae, viz., all change their positions by means of their pseudopods. Following 
the movements of various amebae I have always noted that first on some side 
of the body of the organism there appears a visible thickening, at first showing 
as a light and almost transparent cloud; this thickening (a pseudopod) grows 
more and more, eventually taking on a color nearly like that of the body of the 
ameba and then after one-half, five, ten, twenty minutes, when it has attained a 
certain size and form, it remains for a time fixed, as if it were adhering to the 
glass and becoming hardened in that position. Then the whole body of the 
ameba moves toward the point where the pseudopod has become fastened and 
coincidently the pseudopod diminishes, even to disappearance (at least it becomes 
invisible to the eye of the observer). During the time of the formation of the 
pseudopod, particularly toward the end of that period, the granules of various 
size in the body of the organism move toward the side where the pseudopod 
was formed. Sometimes, however, pseudopods are formed simultaneously in 
two or three places. Then they all begin to get smaller and the body of the 
ameba remains in an unchanged position. Or there is but one pseudopod, and 
when it has attained a certain size it begins to become smaller without the body 
of the organism having moved. Several times I measured the rapidity with 
which an ameba changed position, but found that this commonly varies; but it 
can be said that in one minute the body travels approximately from 0.001 to 
0.003 mm. The amebae which I observed in infusions traveled in the same time 
as a rule considerably greater distances, although their bodies are not larger 
than that of the ameba of my own mouth. Probably this depends on the lower 
consistence of the infusions, since as the fluids evaporate the amebae begin to 
move more slowly. All the amebae which I have encountered in the soft white 
substance invariably present pseudopods of rounded outline; acute forms I have 
never noted in these, although I have seen this last form several times in the 
amebae of infusions. In the amebae of the mouth as in all amebae there is a 
considerable amount of more or less granular material enclosed in the body. 
In the midst of these granules there are one or two larger than the rest 
(nucleus ?). . 

It may be said from these observations (1) that I have found these amebae 
comparatively few times, only six times in eighty-three observations (about 70 
per cent.) ; (2) they are more frequently found on the internal surface of the 
teeth than on the labial side; (3) the amebae have been found only in the lower 
jaw; (4) once I observed them even after very careful cleansing of the oral 
cavity. 


The only points of positive statement in his verbose attempt to 
describe what he observed, are that Steinberg saw in soft tartar motile 
amebiform organisms, with a small number and rounded type of 


pseudopods, the body contrasting with the pseudopods by its granular- 
ity and containing coarser or globular bodies. One or other of the larg- 


THE PARASITE OF ORAL ENDAMEBIASIS 163 


est of the latter he suspected was a nucleus. If he was correct in this 
surmise his amiba buccalis differs in its nucleus from that character- 
izing the ordinary examples of these mouth endamebae; if, as is 
probably the case, these coarse globules were merely remnants of 
ingesta, the nucleus in the parasites with which he was concerned 
was at least difficult to distinguish in the living organism. In the absence 
ef direct statement it is worthless to speculate as to the size of his 
ameba. It is clear that the ectoplasm was hyaline and of a different 
“color” (refraction?) from the endoplasm, but there is no indication 
as to its proportionate amount save that it formed the pseudopods. 
lt is of course utterly impossible to be positive because of the incom- 
pleteness of the description and the uncertainty of data; but at least 
the writers hold that these points are not incompatible with a belief 
that Steinberg’s amiba buccalis was the same species of endameba as 
that now known and described more fully first by Prowazek under 
the same specific name. 

In 1879 Grassi,® in a paper on parasitic protozoa, especially those 
oi man, records (without illustrations) the finding of an ameba, which 
he named amoeba dentalis, in material obtained from gingivitis lesions. 
His brief text follows in the original: 


4. Amoeba dentalis (mihi) (nell’ uomo). E forse uguale alla buccalis di 
Steinberg (la memoria di quell’ autore e rarissima e non poté consultarla neppure 
Leuckart). Ha molta somiglianse coll’ amoeba coli; come essa al disotto dei 
25° C. 6 pochissimo mobile e tiene per lo pitt una forma tondeggiante; a 38° 
—40° C. é vivacissima e protea. Ne trovai numerosi esemplari in tre casi di 
ulite. 

Later, however, although Perroncito also stated that he had 
cbserved these amebae twice in the mouth, Grassi doubted the verity 
cf his observations, suggesting that the supposed amebae were per- 
haps “salivary corpuscles.” ° With our present knowledge there can 
be no doubt that Grassi’s observation of amebae in the human mouth 
was correct; and the points in his brief notice that are especially 
noteworthy are that the parasites were obtained from cases of gingival 
inflammation (probably pyorrhea) and that they much resembled 
ameba coli. (This last statement, it must be remembered, was made 
before the present separation of the old species a. coli into Endameba 
coli, and Endameba histolytica obtained.) It is very significant, too, 
that by Grassi’s counsel, and more or less under his direction, the 
dentist Chiavaro in 1914 devoted a study to Endameba buccalis 
Prowazek," in which he states that “probably Entameba buccalis 


5. Grassi: Gazzetta med. Ital-Lomb., vol. 39 (8th series, vol. 1), p. 446; 
Nov. 8, 1879. 

6. Grassi: Cf. Railliet, Traité de Zool., méd. et agricole, Paris, 1895, p. 118. 

7. Chiavaro: v. sup. for abstract; original, Ricerche sull’ Entamoeba buccalis, 
Lavoro eseguito nel R. Instituto di Anatomia Comparata della Universita di 
Roma diretto dal Prof. B. Grassi, Roma, 1914. 


164 THE JOURNAL OF PARASITOLOGY 


described by Prowazek should be identified with amoeba gingivalis 
Gros (1849), with Entameba buccalis, Steinberg (1862), with 
Amoeba dentalis Grassi (1879) and with the ameba found by Flexner 
in 1892 in Baltimore in an abscess of the lower jaw.” Under such 
circumstances there seems little reason for extended discussion, and 
the writers accept in full the identity of Grassi’s organism with that 
of Prowazek. 

In 1904 Prowazek® announced his discovery of a parasitic ameba 
of the human mouth, under the name of Entamoeba buccalis, without 
reference to the earlier work above detailed, and repeating for his 
declaredly new species a name previously appropriated by Steinberg 
for an organism of the same genus and of the same habitat. His 
article is easy of access and forms the basis for the texts of pre- 
vailing works upon animal parasitology, and is confirmed in the writ- 
ings of other observers ;? for which reasons there is no need of detail- 
ing here more than the important data included in his original article. 
He met these organisms in material from the cavities of decayed 
teeth, first in Rovigno and later in several individuals in Trieste. He 
describes them as varying from 0.006 to 0.032 mm. in diameter when 
at rest; provided with a distinct ectoplasmic border, hyaline and 
refractive; a granular endosarc full of food vacuoles and ingested 
globular masses; mononucleated (the nucleus commonly deep in the 
body, small, 0.0015 to 0.0045 mm. in diameter, round, vesicular, poor 
in chromatin, with small, deeply chromatic ‘“binnenkorper,” a thick 
nuclear membrane refractive and of greenish tint and often showing 
chromatin granules collected along its inner limit) ; the whole nucleus 
of firmer consistence than that of Endameba histolytica Schaudinn 
and not compressible by the coarse ingested masses in the endosarc; 
endowed with active motility; pseudopodia few, broadly lobose and 
rounded, but sometimes forming an elongation of the animal as a single 
broad pseudopod; without contractile vacuole. He speaks of the fre- 
quent presence of residua of leukocytic nuclei in the nutrition vacuoles ; 
and describes reproduction by simple division after nuclear swelling, 
mitotic changes in the binnenk6orper and division of the nucleus. He 
also calls attention to what he believes to be chromidia of nuclear 
origin in the cytoplasm, which he suggests may develop into complete 
nuclei of young amebae (which then separate from the parent by 
gemmation) ; but at time of publication he has not met evidence of 
reproduction encystment. He recognizes a general resemblance to 
Endameba coli (Losch) and Endameba histolytica Schaudinn, but dif- 


8. Prowazek: Arbeiten aus d. Kais. Gesundheitsamte, vol. 21, p. 42. 


9. Cf. Leyden and Lowenthal: Charite Annalen, vol. 29, p. 3, in a case of 
cancer of mouth. 


THE PARASITE OF ORAL ENDAMEBIASIS 165 


ferentiates it from the former by its clearer and complete hyaline 
ectosare and by the differences in the observed modes of reproduction ; 
and from the latter mainly by the greater rigidity of its nucleus and 
more definite structure of the nuclear membrane. 

These characters in a general way the writers can corroborate, but 
in some points would insist upon a greater latitude of variation than 
the outline given above would indicate. And in fact Prowazek in 
his article, in commenting upon the completeness of the ectosarc, 
specifically indicates much variation in its thickness; and, in speaking 
cf the rigidity of the nucleus, acknowledges that in rare instances 
when it is, as occasionally may be noted, in eccentric position, close to 
the ectosarc, it may show indentation in the varying movements of 
the animal. Leyden and Lowenthal’ who identify their organisms 
with that described by Prowazek vary from his statements as to the 
size (0.008 to 0.020 mm.) of the organism, the uniformity of dis- 
tinction of ectosarc and endosarc and as to the position of the nucleus 
(sometimes at border of endosare and ectosare but usually central) ; 
and they fail to recognize in the living animal the peculiar greenish 
shimmer mentioned by Prowazek in the nuclear membrane, suggesting 
the operation of the personal equation in the observation. In our 
earlier papers upon this subject the writers have held that of the 
endamebae of the various cases of pyorrhea examined all but one or 
two (tentatively held as Endameba kartulisi Doflein) were examples 
of Endameba buccalis Prowazek, but suggested that perhaps fuller 
study might indicate that of the larger group some should be referred 
to a third, unidentified species. This last point was based upon the 
fact that occasional examples varied beyond the usual size, attaining 
as much as 0.038 or 0.04 mm diameter, that these were apt to show 
a greater general activity of movement, and often extruded unusual 
numbers of pseudopods and these of unusual shapes (often small 
drop-like projections, or small projections of the same type upon the 
border of the main pseudopods). Further study has led us to believe 
these features are not of specific differentiating value, and as the other 
characters, studied in the stained specimens, are identical we are of the 
opinion that such forms are merely exceptional. individuals of one 
general species. While in a given material some examples may have 
attained the size mentioned, the greater number were smaller; and 
while in a given observation a greater activity of the amoebae of a cer- 
tain individual was noted, a second preparation on the same or a subse- 
quent day from the same person has repeatedly failed to show the same 
degree of motility. And in one and the same ameba we have repeatedly 
seen alternate periods in the course of a brief observation of the living 
animal when the pseudopods would vary from one or two large, 


166 THE VWOURNAL iOF “PARASITOLOGY 


rounded lobose projections, to longer and digitate types, to be suc- 
ceeded perhaps in a short while by numerous small drop-like pro- 
jections of the ectosarc. For such reasons we are satisfied occasional 
variations, even if marked, cannot be insisted upon for specific identi- 
fication, and that only the common type, as the mean number, size 
and form of the pseudopods, should be held as of value in this 
connection. With this preface our description of these parasites may 
be outlined as follows: Naked parasitic amebae of usual diameter in 
resting examples of 0.030 to 0.035 mm. (with exceptional instances 
reaching 0.040 or slightly above) ; with refractile and faintly greenish- 
tinted hyaline ectosarc well defined from the granular endosarc, but 
sometimes so thin as to be easily overlooked; endosare granular, 
colorless and in all but the more minute examples containing few 
to many digestion-vacuoles in which globular detritus of leukocytic 
nuclei and red blood cells are commonly found along with bacteria ; 
with a small (0.002 to 0.005 mm.) rounded nucleus, invisible or at best 
uncertainly distinguishable in the unstained specimen, usually central 
or subcentral in position (Fig. 3; a, b), but at times eccentric (when 
the ingesta push it to one side) (Fig. 3; c, d, e). The difficulty of 
distinguishing the nucleus in the living animal prevents the writers 
from expressing a positive opinion as to its greater rigidity than that 
possessed by the nucleus of Endameba histolytica Schaudinn, but we 
have certainly met in stained specimens oval and slightly indented 
nuclei which makes us hesitate to accept this point which Prowazek 
especially indicates as distinctive from the dysentery endameba (Fig. 
3; f,g,h). The nucleus is very poor in chromatic substance, vesicular, 
with a small “binnenkorper,” sometimes showing a minute centriole, 
a clear space between it and the nuclear border containing no chro- 
matin or at most a very few incomplete threads; and the border is 
represented by a thin but somewhat irregular line of chromatin, 
about which the writers are unable to recognize a further membrane 
and which they regard as the membrane itself. The thickness of this 
membrane is not absolutely fixed, sometimes more delicate, sometimes 
less so, but always thin, with scattered parts thicker than others 
or with scattered chromatin granules on its inner surface (Fig. 
4). The degree of motility manifested by the parasites is to us 
fairly comparable to that of the dysenteric endameba (Fig. 5). The 
pseudopods as a rule are few (one, two, or three), usually broadly 
lobose and commonly attaining a maximum length of the diameter of 
the endosare. Not infrequently a single extension may reach even a 
greater length, making the full long measurement of the parasite 70 
or more micromillimeters. Or occasionally there are more pseudo- 
pods, these then small and guttulate. The pseudopods are composed 
practically entirely of the ectosarc, the granular endosare terminating 


THE PAKASITE OF ORAL ENDAMEBIASIS 167 


at the base, or extending but a little into the larger ones. We have 
observed examples containing two nuclei (Fig. 3; 1) and have seen 
binary division of the living ameba take place; and have repeatedly seen 
small protoplasmic masses separate by gemmation (some of these con- 
taining minute particles of chromatin) ; although we are uncertain as to 
definite chromidial formation, as we are confused by bacteria and bac- 
terial fragments which are numerous in the larger amebae and which 
stain very like the chromatin with Giemsa stain and with iron-hema- 
toxylin which we have usually used for study. We have found “dauer” 
cysts, but thus far no reproduction cysts. 

With these data in hand the writers do not hesitate, in spite of the 
published differences (which we believe are due to nonspecific varia- 
tions), to identify the organism with which we have become fairly 
familiar, with that of Prowazek. As above indicated, we see no reason 
to believe the Ameba dentalis of Grassi to be other than the same spe- 
cies, if we may accept identity of habitat, identity of lesion, comparable 
morphology (as expressed in terms of the dysenteric endameba), and 
the evident later opinion of Professor Grassi as to identity (inferable 
from his relation with Chiavaro’s paper). It is impossible to be sure 
of Steinberg’s Amuiba buccalis; but identity cannot be denied or 
specifically asserted. The Amoebea gengivalis of Gros is so nearly like 
the same organism, as shown by his drawings and a few points in the 
text, that it is impossible to say it is not the same and quite within 
reason to say that it probably is identical. Gros may therefore be held 
as probably the original observer of the common oral endameba with 
which we are today familiar ; and by rule of priority, with modification 
of spelling of gengivalis to gingivalis to conform with etymological 
propriety this organism should take the nomenclature Endameba 
gingivalis (Gros) instead of the more common present-day name 
Entameba buccalis Prowazek. In this attitude in fact the writers are 
not the first.’° 

In addition, the writers feel that further attention should be given 
to certain amebae which have been met by Kartulis,!! Flexner,” 
Verdun and Bruyant'* and Bruyant and Pelissier!* in the same 
comparative lines. The first and second refer to amebae met 
in the pus of abscesses of the lower jaw, the third to organ- 
isms in the pus of two symmetrical abscesses of the cheeks, and the 


10. Brumpt: Précis de Parasitologie, 1st and 2d editions, Paris, 1910 and 1913. 

11. Kartulis: Ztschr. f. Hygiene, 1893, vol. 13, p. 9; and Kolle u. Wasser- 
mann: Handb. d. pathogen. Mikroorg., Ist ed., 1907, vol. 1, p. 356. 

12. Flexner: Johns Hopkins Hosp. Bull., November, 1892, vol. 3, p. 104. 

13. Verdun and Bruyant: L’Echo méd du Nord., Aug. 11, 1907, vol. 11, p. 375. 

Re ela and Pelissier: L’Echo méd. du Nord., June 29, 1909, vol. 13, 
No. 26. 


168 THE JOURNAL OF PARASITOLOGY 


fourth to amebae in pus from suppurative gingivitis. Flexner’s ameba 
was regarded by himself as indistinguishable from the dysenteric ameba 
(endameba histolytica?), an organism apparently with no marked dis- 
distinctness of differentiation between the homogeneous ectosare and 
the granular endosarc, the latter containing numerous vacuoles and 
showing in its interior red blood cells and their detritus. The nucleus 
was not recognized in the living cell; the pseudopods were character- 
istically blunt, varying from a mere bulging to a change in which the 
greater part of the ameba was protruded. No actual measurements 
were published by the observer, and no drawings accompany the text. 
It is usually classed as endameba Kartulisi. General conformity to the 
characters above indicated for Endameba gingivalis (Gros) seems to 
the writers, however, to be included in these incomplete data. That 
Endameba gingivalis (Gros) may be met in such maxillary abscesses 
the writers can testify positively on the basis of two cases. One of 
these occurred secondarily to alveolar fracture occurring in the extrac- 
tion of a carious tooth, and was accompanied in its course of three or 
four years by the discharge of sequestra from the jaw and extension 
of the suppuration to the surrounding soft parts in the cheek and 
floor of the mouth, with establishment of an external fistula. At the 
time of discovery of the amebae in this case the fistula had healed, 
but sequestra were from time to time being discharged through the 
gingival tissues into the mouth. The mouth was kept scrupulously 
clean by the patient and no amebae were detected about the remaining 
teeth or over the exposed surface of a small sequestrum which was 
gradually being dislodged into the mouth; but when this was extracted 
numerous amebae of the ordinary gingivalis type were detected in 
spreads from its embedded surfaces. The case was treated with emetin 
and has promptly and completely cleared up. The second case was 
regarded as a dental cyst of the lower jaw, but found by the surgeon 
to be a chronic maxillary abscess in the pus of which the writers found 
large numbers of endamebae which were as a rule of larger size than 
usual, quite active, very commonly contained red blood cells, but on 
close study of stained specimens were also identified with the ameba of 
Gros. There seems but little reason, therefore, to regard the organ- 
isms of Flexner’s case as specifically different. The impression has 
grown upon the writers that the ameba of Flexner became associated 
with that of Kartulis into an isolated species mainly because these cases 
of Flexner and of Kartulis were both of suppuration of the lower jaw, 
both published at nearly the same time and appeared before any 
detailed attention had been given to oral amebae, Prowazek’s study 
not being brought forward until a decade later. Prowazek, at the 
close of his article above referred to, promised a further and fuller 


THe FPAnosits OF ORAL ENDAMESIASIS 169 


description of his organism with differentiation from the organism of 
Kartulis ; but the writers have failed to find this later article if it be 
in existence. 

In 1893 Kartulis'? announced his discovery of amebae in the pus 
from an abscess of the lower jaw (Fig. 6), and subsequently’® reported 
similar findings in five more cases of suppurative osteomyelitis of the 
jaw. These organisms were named in honor of the discoverer by 
Doflein Endameba kartulisi, prior to the publication of the specific name 
maxilaris, given by Kartulis (the latter now appearing as a synonym). 
In all three references (supra) to these observations of Kartulis his 
first impression of similarity to the dysenteric ameba is noted. Differen- 
tiation is made because of the somewhat larger size of the organism and 
its higher degree of activity, both progressive and pseudopodial. In 
the original description, too, the nucleus is declared to be smaller and 
thus not comparable to the nucleus of the organism of dysentery ; but 
it must be recalled that at the time Endameba coli (Losch) was still 
included with the species now known as Endameba histolytica Schau- 
dinn, and comparison with the larger nucleus of the former (readily 
observed in the unstained specimen and staining more deeply) might 
tairly be the cause of this statement. Kartulis describes the nucleus 
as small, rarely distinguishable in the unstained specimen, vesicular, 
and provided with an easily seen nucleolus (in stained state). It is 
said to be surrounded by a clear zone, referring apparently to a finely 
reticular perinuclear area of the endosarc. Comparing the text cuts 
and the colored plate illustrations of the original article by Kartulis, 
the diameter of the nucleus (not definitely stated) must be about 5 or 
€ micromillimeters; and while in both the text cut and the colored 
plate it would appear to be a relatively solidly chromatic body, the 
“vesicular” character described indicates that the “nucleolus” is: a 
small “binnenkorper” surrounded by a relatively clear plasm, about 
which a probably fairly marked nuclear wall occurs separating the 
intranuclear substance from the light reticular perinuclear part of the 
endosarc. The ectosarc is described as clearly seen in the pseudopodia, 
but (in the resting stage) not apparent as a peripheral zone. Both in 
the original text and in the cuts the pseudopods are indicated as few, 
large and digitate (in the later descriptions said to vary from lobose 
shape to long and comparable to the “horns” of a snail), reaching per- 
haps several times the length of the body diameter. If the above inter- 
pretation of the nuclear picture be correct the points of distinction 
from Endameba gingivalis (Gros) rest more particularly upon the 


15. Kartulis: Ztschr. f. Hyg. u. Infectionskr., vol. 13, p. 9. 

16. Kartulis: Centralbl. f. Bakt. u. Parasitenk. 1 Abt., Ref., vol. 33, p. 471; 
1 Panhellen. Med. Congress in Athens, May 6-11, 1901; see also Kolle u. Was-. 
sermann, Handb. d. pathogen. Mikroorg., 1st ed., vol. 1, 1907, p. 356. 


' EXPLANATION OF .PLATE 


Fig. 1—Photographic reproduction of that portion of the plate of illustrations 
accompanying article by Gros in 1849, which depicts his Amoebea gengivalis. 


Fig. 2.—Photographic reproduction of part of plate illustrating article by 
vy. Leyden and Lowenthal upon Endameba buccalis Prowazek, showing organisms 
in motion. 


Fig. 3—Camera lucida drawings of Endameba gingivalis (Gros), stained 
with iron hematoxylin; a and b showing the usual central or subcentral position 
of the nucleus; c, d and e, examples with the nucleus in eccentric position; 
f, g and h, examples showing nucleus in compressed condition; i, an example 
with two nuclei (it is suspected, although not known, that the small ameba 
lying within the same space in the stained film had been recently separated from 
the larger one.) 


Fig. 4—Photomicrograph of Endameba gingivalis (Gros), stained with iron 
hematoxylin; from material from pyorrhea pocket. 


Fig. 5—Composite outlines of moving Endameba gingivalis (Gros), includ- 
ing five camera lucida sketches; time included, twenty seconds; to show activity 
of movement and long type of pseudopod at times assumed; magnification as 
in Figure 3. 


Fig. 6.—Photographic reproduction of a text cut of Endameba kartulisi 
D6flein from original article by Kartulis in 1894. 


Fig. 7—Photographic reproduction of text cut illustrating article in 1907 by 
Verdun and Bruyant, showing Endameba pyogenes Verdun and Bruyant. 


Fig. 8—Photographic reproduction of cut of endameba described by Ribbert, 
here shown in parotid duct. 


Fig. 9—Endameba mortinatalium Smith and Weidman, in minute hepatic 
abscess; stained with iron-hematoxylin. 


igen Dewerungen 


rfalt 


solbe in manniz 


Fig. 6 


7 gle et 
pal % 


Fig. 8 


. agen 


Aba Vues i) 


20 $e be 
G 


Fig. 7 


THE PARASITE OF ORAL ENDAMEBIASIS 171 


size of the organism, the size and shape of the pseudopodia, the activity 
of movement and the lack of a clear ectosarcous border—in all of 
which particulars nonspecific variations of at least comparable degree 
may occur. Certainly in the occasional organisms which we have in 
the living state suspected of showing the characters of the ameba of 
Kartulis because of these latter points, the writers have seen the indi- 
vidual change and assume the general features of Endameba gingivalis 
(Gros), and subsequent study of stained examples has led us to con- 
clude identity with the latter. We are of opinion, therefore, that there 
is not sufficient basis for accepting the specificity of Kartulis’ type of 
these amebae, and would refer it also to the species gingivalis of Gros. 

There remains of this group of parasitic amebae of the mouth for 
comparison the organism known as Endameba pyogenes of Verdun 
and Bruyant,™ studied by these writers in the pus from two symmet- 
rical abscesses of the cheeks in a case under the surgical care of Dubar 
and Leroy, in which there had preceded the abscesses carious teeth 
and pyorrhea lesions, to which the clinicians were disposed to attribute 
the abscess development (Fig. 7). Later Bruyant and Pelissier** men- 
tion the discovery of similar amebae in two cases of gingival suppura- 
tion, but with no more than partial description refer for their characters 
to the original article by Verdun and Bruyant. The mean diameter of 
these parasites is given as from 0.03 to 0.035 mm. They are described 
as quite active in movement, with large rounded pseudopodia rapidly 
projected and retracted. The pseudopods are hyaline in appearance, 
the endosarc granular ; the ectosarcous border is not clearly seen, being 
absent or only visible in the pseudopods and their immediate bases. 
The endosare is commonly full of digestive vacuoles in which rem- 
nants of erythrocytes and leukocytes are to be detected. The nucleus 
is described as relatively large, from 0.008 to 0.015 mm. (from one 
third to one half the diameter of the resting ameba), always visible, 
granular but paler than the surrounding endosarc. Double contoured 
cysts, from 0.006 to 0.015 mm., are described and said to frequently 
contain multiple, but never more than four, nuclei. Larger cysts, with 
single wall and a single unchanged nucleus are described, and perhaps 
are resistance encystments. Stained with Borrel blue and eosin, the 
body of the ameba is light blue, the nucleus (distinguished from the 
deeper blue remnants of leukocytic nuclei and copper-red residua of 
red blood cells about it) is apparently stained diffusely a reddish vio- 
let tint; is granular and often shows a well-defined nucleolus (binnen- 
korper). In brief, the size of the nucleus, its richness in chromatin 


17. Verdun and Bruyant: L’Echo méd. du Nord., Aug. 11, 1907, vol. 11, Desi: 
‘ rh and Pelissier: L’Echo méd. du Nord., June 27, 1909, vol. 13, 
Yo. 26. 


172 THE JOURNAL OF PARASITOLOGY 


and its visibility in unstained specimens, along with the mode of repro- 
duction within a cyst, mark this as a species of these mouth amebae 
distinctly different from those hitherto discussed in this paper; and as 
such it must be kept clearly in mind in studies of oral endamebiasis. 

It is impossible to come to a definite conclusion as to the relation- 
ship of this last organism with certain other endamebae which have 
been described from the human body which contain large and richly 
chromatic nuclei because of the deficiency of data on both sides, but 
it may be suggested that in this connection there should be remem- 
bered certain organisms described by Smith and Weidman’® under 
the name Endameba mortinatalium, being found by them in small 
abscesses in the liver and kidneys and also in the lungs of a still-born 
fetus (non-syphilitic). This these writers identify in a later note 
(October, 1910) with unnamed organisms met by Jesionek and 
Kiolemengolou”’ in the kidneys, liver and lungs of a syphilitic eight 
months fetus, and also by Ribbert* in the renal tubules of a syphilitic 
new-born infant twenty years before his publication, and twice there- 
after in the parotids of nonsyphilitic infants (Fig. 8). Tietze?* also 
records the discovery of amebiform organisms in a parotid tumor in a 
child of about 4 years of age; but these were held by Schaudinn, who 
examined histological sections, to be either identical to or akin to 
Prowazek’s endameba. Smith and Weidman** have recently encoun- 
tered the same large-nucleated ameba in the lungs of a congenitally 
syphilitic baby. These organisms (Fig. 9) in fixed and stained state, for 
the most part measured 0.025 to 0.032 mm. in diameter; the nucleus 
spherical or oval and usually from one third to one half the cell 
diameter. Considerable variation exists in the amount of ectosarc, 
which however in some examples is seen as a complete clear border 
zone in the stained examples. The endoplasm is highly granular, con- 
taining at times red blood cells and leukocytic detritus, and in some 
instances is full of chromidia-like bodies. The nucleus contains a 
very large, granular and richly chromatic binnerk6érper, occasionally 
showing a centriole; about the binnenkérper a narrow clear zone of 
nuclearplasm and a delicate chromatin-staining nuclear wall, with 
threads or grains of chromatin scattered in the clear zone. Pseudo- 
podia few and rounded in the stained specimens. The occurrence of 
these organisms in the parotid and their general comparability suggest 
that further study of relation be made. 


19. Smith and Weidman: Univ. of Penna. Med. Bull., September, 1910. 

20. Jesionek and Kiolemengolou: Miinchen. med. Wchnschr., 1904, No. 43, 

21. Ribbert: Centralbl. f. allgem. Pathol., 1904, vol. 15, p. 945. 

22. Tietze: Mittheilung. aus d. Grenzgebiet. d. Med. u. Chir., 1905, vol. 15, 
Dace: 

23. Smith and Weidman: Am. Jour. Trop. Med., vol. 2, p. 256, October, 1914. 


THE: PARASITE OF ORAL ENDAMEBIASIS 173 


Finally the writers (with natural hesitation because of full appreci- 
ation of the resultant confusion in our current views as to the rela- 
tions of endamebae to dysentery and the impossibility of satisfactorily 
explaining a great field in the etiology and pathology of endamebic 
dysentery and its immediate complications as the liver abscess, if this 
statement be thought worthy of consideration) feel constrained to 
acknowledge that from a purely morphological standpoint we are 
unable to differentiate the organism which we believe to represent 
the vast majority of oral endamebae and to occur in an extremely large 
number of persons not merely in the tropics but all over the world, 
from Endameba histolytica Schaudinn. We are unwilling to make 
any assertion which involves biological identity in full, merely asserting 
that the morphological similarity is so close that we feel unable to 
make a distinction from microscopic observation alone. The limits 
of size of the two organisms are too close to permit this to serve as 
a specific difference ; in both (Fig. 3; a, b, c, d, e) there is a tendency 
to clear ectosarcous differentiation from the granular endosare in which 
cellular detritus and especially red blood cells and their debris may be 
seen ; in both there is a small nucleus (the position of which is not fixed 
for either) of vesicular type, poor in chromatin, practically mvisible in 
the unstained specimen, and showing the same small binnenkorper, the 
same plasmatic space between the latter and the nuclear border, which 
is formed by a delicate but variably irregular and chromatic nuclear 
membrane; both show few pseudopodia characteristically, and these 
usually of broad lobose type; and the general type of motility of both 
the cell and the pseudopods is closely comparable in the main but 
variable in both. Both forms, too, divide by binary fission and by 
gemmation,** both fail to form reproduction cysts as far as is known. 
And if it be a characteristic of Endameba histolytica Schaudinn to 
destroy red blood cells, so, too, is Endameba gingivalis (Gros) cap- 
able of rapid digestion of these same elements. We have repeatedly 
watched the complete disappearance of freshly englobed erythrocytes 
in the living ameba of Gros, the red cell fading before our eyes to 
invisibility in from three to five minutes. 

Prowazek in his original article compares his ameba, which we have 
above held to be identical with Endameba gingivalis (Gros) with 


24. Note by Editor: Gemmation, as a form of division in E. hystolytica, has 
been proved not to occur, the so-called gemmation being due to degenerative 
changes. In E. histolytica reproduction cysts occur, of course; the four-nucle- 
ated cyst of this species being easily distinguished from the eight-nucleated 
cyst of the harmless E. coli. If it be true that reproduction cysts do not 
occur in E, gingivalis, this alone would serve to distinguish this species from 
E, histolytica. Likewise the tetragena type of nucleus of E. histolytica does not 
occur, according to the author’s description, in E. gingivalis. 


174 THE JOURNAL OF “PAKASITOLOGY 


Endameba histolytica Schaudinn, acknowledging its close conformity, 
but differentiating it by the point that its nucleus is more rigid, less 
likely to present compressed, flattened outlines. Such a point is exceed- 
ingly questionable ; nuclear deformation may depend as much upon the 
amount and rigidity of ingested substances and the movement pressure 
of the cell as upon any special nuclear consistence. Prowazek from 
his text gives the impression that this is best appreciated in the living 
and moving organism; but it is difficult to observe the nucleus of either 
one in this state. Occasionally at least the writers have met slightly 
indented and oval nuclei in stained specimens of Endameba gingivalis 
(Gros). 

Even if this suggestion be refused, the writers feel there is need of 
a more easily demonstrable differentiation, and believe that more than 
merely morphological studies are requisite to prove the dual specificity. 


ACANTHOCEPHALA IN NORTH AMERICAN 
AMPHIBIA * 


H. J. Van CLEAVE 


A careful search of the literature has revealed but a single instance 
in which Acanthocephala have been found parasitic in North 
American Amphibia. Stiles and Hassall (p. 352) record the occur- 
rence of Acanthocephala in Diemyctylus viridescens, Raf. taken in 
Maryland by Dr. Hassall, though no determination of the species is 
given in the work cited. Through the courtesy of Dr. B. H. Ransom 
of the U. S. Bureau of Animal Industry the writer has been per- 
mitted to study these undetermined forms. The label accompany- 
ing this collection of seven worms bears the additional information 
that the host was taken at Franklin Falls, Baltimore, Md., in May, 
1893, and that they were from the intestine. The location of the 
brain (Fig. 1) at the base of proboscis sheath, together with the 
fact that the retinacula proceed directly from the posterior end of the 
sheath give sufficient data for ascribing these specimens to the genus 
Acanthocephalus Koelr. Further the writer has determined them as 
belonging to the species A. ranae (Schrank). 

The recent work of Lihe (1912) upon variability in the number 
of proboscis hooks in this species has led the writer to make a 
study of this point in the material at hand. In forty-three speci- 
mens collected from the same locality Lihe found the number of 
longitudinal rows of hooks varied from thirteen to nineteen (1912, 
p. 297), while the number of hooks in each row varied within the 
limits of four and six. Some individuals had rows of four hooks 
alternating with rows of five, some had five in each row, some had 
rows of five hooks alternating with rows of six hooks, while still 
others had six hooks in each row. Of the seven individuals of the 
American form which the writer has studied, four have the proboscis 
fully protruded. In every one of these the proboscis is armed with 
twelve rows of hooks and there are six or seven hooks in each row. 
These numbers agree precisely with the data given by Porta (1908, 
p. 228) for the hooks of A. ranae (Schrank). Unfortunately Porta 
does not give measurements for the hooks of the form he described 
under this name. He describes the embryos as being 0.07 to 0.09 
mm. in length while Luhe (1911) records a length of 0.11 mm. and 


* Contributions from the Zoological Laboratory of the University of Illinois, 
under the direction of Henry B. Ward, Urbana, IIl., No. 45. 


176 THE JOURNAL OF PARASITOLOGY 


a breadth of 0.013 mm. for embryos of A. ranae from Germany. 
If the two authors are describing the same species there is far greater 
range of variability in the size of the embryos of this species than 
has come to the attention of the writer in a study of embryos of 
inany species of Acanthocephala from the United States. 

A comparison of hook lengths in the American form with Luhe’s 
data for A. ranae from Germany is given here, following Luhe’s 
method of designating each hook. Since the hooks in two adjoining 
longitudinal rows alternate, those in the longest row are numbered 
from the tip posteriad: 1, 3, 5, 7, etc., while the hooks in the adja- 
cent row are: 2, 4, 6, 8, etc. Liihe’s measurements are for but a 
single row. 


Hook LENGTHS IN ACANTHOCEPHALUS RANAE (SCHRANK) 


American German Form 
Hook Form Data from Lthe 
1 59u 60" 
2 71 ee 
3 71 7) 
4 7 My 
5 Fal 75 
6 Hil ca 
7 Tif 80 
8 77 e 
9 Wa aS 
10 71 —_ 
11 Hil 50 
12 53 
13 30 — 


Attention should be called to the fact that in representatives of 
this species found in North America the basal hooks in some rows 
are very much shorter than the basal hooks in the row adjoining 
(cf. 12 and 13 above). 

Inasmuch as Lithe has found such great variability in numbers 
of hooks in Acanthocephalus ranae it is not beyond reason to expect 
that in his relatively small number of individuals (43) he did not 
include the full range of variability. The writer supports Porta’s 
record of twelve longitudinal rows of hooks. The depression ot 
Lithe’s lower range of variability for number of longitudinal rows 
of hooks by one, and the extension of his upper range of the num- 
ber of hooks in each of these rows similarly by one, are thus within 
the bounds of variability in this species. It was in view of these facts 
that the writer found it necessary to ascribe the specimens of the 
single North American collection of Amphibian Acanthocephala to 
the species Acanthocephalus ranae (Schrank). Unfortunately none 
of the specimens contained fully formed embryos. For that reason 
measurements of embryos had to be omitted from the all too few 


ACANTHOCEPHALA IN NORTH AMERICAN AMPHIBIA 177 


sources of data of value in the determination of species in the 
Acanthocephala. 

The fact that there has been but one published record of Acantho- 
cephala in Amphibia of North America led the writer into an 
investigation to determine whether this might be due to inadequate 
study and records of Amphibian parasites in this country or to a 
comparatively infrequent infestation of Amphibians with parasites 
of this class. The writer, personally, has records of the examination 
of over one hundred fifty Amphibia for parasites, chiefly from 
IHinois, none of which harbored Acanthocephala. The records of 
Leidy’s extensive researches in parasitology, while including many 
references to other forms parasitic in Amphibia, contain no mention 
of Acanthocephala in that group. Dr. H. B. Ward has very kindly 
granted permission to include results of the examination of about 
fifty Amphibia contained in the records of his parasitological col- 


Fig. 1.—Acanthocephalus ranae (Schrank). Toto mount ¢. Stain, Ehrlich’s 
Acid Hematoxylin. Damar mount; br, Brain; re, Retinacula; ta, Anterior 
testis; tp, Posterior testis; cg, Cement glands; bu, Copulatory bursa. 


lection. His materials represented collections from seven different 
states in the central and western United States. His records indicate 
the absence of Acanthocephala in all Amphibia examined. The 
writer is also indebted to Dr. George R. La Rue who very kindly 
furnished data from the records of his collections. In over one 
hundred and thirty hosts, including numerous species both of Urodela 
and of Anura from six different states, including eastern, central, and 
western states, La Rue found no Acanthocephala. From all sources, 
then, the writer has data showing the absence of Acanthocephala in 
above three hundred specimens of Amphibia distributed in the fol- 
lowing states: Illinois, Michigan, Kansas, Nebraska, Ohio, Pennsyl- 
vania, North Dakota, Oklahoma, and Missouri. Such a condition 
stands in marked contrast to the records of European investigators 
who have recorded several species of Acanthocephala from Amphibia 
with many cases showing high percentages of infestation. Thus, for 


178 THE JOURNAL OF PARASITOLOGY. 


example, Muhling (p. 55) found 50 per cent. of Rana esculenta 
infested with A. ranae (—E. haeruca). European Amphibia also 
serve as intermediate hosts for larval Acanthocephala which attain 
maturity in the intestine of birds. Corynosoma semerme and 
Centrorhynchus aluconis both pass their larval stage in European 
Amphibia. So far no larval Acanthocephala are known in North 


American Amphibia. 
REFERENCES CITED 


Leidy, Joseph, Jr. Researches in Helminthology and Parasitology. Smith- 
sonian Misc. Coll., 1904, 46: 1-281. y 

Lihe, M. Die Stisswasserfauna Deutschlands. Heft 16, Acanthocephalen. 
Jena; 1911, p. 116; Zur Kenntnis der Acanthocephalen. Zool. Jahrb., 1912, 
Suppose BdanlisZ/Ae3065. 2eplt 

Mihling, P. Die Helminthen-Fauna der Wirbeltiere Ostpreussens. Arch. 
Naturg., 1898, 1: 1-118; 4 pl. 

Porta, A. Gli Acantocefali degli Anfibii e dei Rettili. Arch. Zool., 1908, 
33225-2593 1splt 

Stiles, C. W., and Hassall, A.: A preliminary catalogue of the parasites 
contained in the collections of the United States Bureau of Animal Industry, 
United States Army Medical Museum, Biological Department of the Univer- 
sity of Pennsylvania (Coll. Leidy) and in Coll. Stiles and Coll. Hassall. Vet. 
Mag., 1894, Phila. 1: 245-253, 331-354. 


fat PROTECTION OF PARASITES IN. THE DIGESTIVE 
TAC AGAINS. Genk ACTION OF THE 
DIGESTIVE ENZYMES 


W...2.- BURGEAND E. Ls BurcE 
Physiological Laboratory of the University of Illinois. 


In carrying out an investigation on the rate of oxidation of 
enzymes and their corresponding pro-enzymes it has been necessary 
to make use of many dogs for collecting pancreatic juice and pre- 
paring secretin and enterokinase. Tapeworms and roundworms were 
found in the intestines of many of these animals and the question 
so often raised presented itself, viz., why is it that these worms 
are not digested by the trypsin? Various explanations have been 
offered in answer to this question, such as the existence of an 
antisubstance in the worm which inhibits the action of the trypsin, 
or the resistance of the cuticle to the activity of the enzyme or the 
fact that the parasites are alive, etc. Lillie and others have shown 
that the mucosa of the stomach and intestine possesses intense 
oxidative properties and Burge has found that trypsin, in common 
with all the digestive enzymes, is relatively easy to oxidize. On 
the basis of these two facts we have advanced an hypothesis accord- 
ing to which the mucosa of the digestive tract by means of the 
oxidative processes going on in its cells is able to maintain its integ- 
rity during life by rendering inactive the enzyme solution immediately 
in contact with it. This assumes that there are two opposing activi- 
ties at work, viz., the active enzyme within the lumen of the digestive 
tract attempting as it were to digest the cells of the mucosa, while 
the oxidative processes of these cells are rendering the enzyme inactive 
and hence protecting the mucosa from digestion. The same explana- 
tion might be given for the fact that parasites are able to live in 
the intestinal juicés without being digested. The assumption is that 
the oxidative processes going on in the cells of the parasite exposed 
to the action of the trypsin are oxidizing the enzyme. Thus the 
parasite, like the mucosa of the tract itself, is protected from 
digestion. 

The following experiments and observations were made to deter- 
mine if any experimental evidence could be brought forward in sup- 
port of this assumption: 


180 THE VTOURNAL (OF PARASITOLOGY 


A dog was etherized and killed with chloroform. The intestine of this 
animal was slit open and the tapeworms and roundworms removed. The duo- 
denum and several inches of the intestine following were thoroughly washed 
and the mucosa gently scraped with the handle of a scalpel. Enterokinase was 
prepared by extracting this scraping with 0.7 per cent. sodium chlorid. The 


Rican 
injured tapeworm. 
A’, accompanying 
Mett’s tube. 8B, 
posterior portion 
of tapeworm, the 
anterior portion of 
which was killed 
with induction 
shocks before the 
worm was_ intro- 
duced into the 


pancreatic juice. 
B’, accompanying 
Mett’s tube. 

C’, Mett’s tube 
that was in the so- 
lution with the 
dead worm C. 

The light por- 
tions of the Mett’s 
tubes show the ex- 
tent to which the 
gelatin was di- 
gested. 


secretin was prepared by extracting the hashed mucosa with 200 c.c. of 0.4 per 
cent. hydrochloric acid. This extract was boiled and neutralized while boiling 
with 1 per cent. sodium hydroxid. On filtering a perfectly clear solution was 


obtained. This secretin was injected into the jugular vein of an etherized dog 
and approximately 100 c.c. of clear pancreatic juice were obtained from the 


pancreatic duct. 


PROTECTION OF .PARASITES 181 


Thirty c.c. of this pancreatic juice were activated by the addition of 3 c.c. 
of enterokinase. This trypsin solution was sterilized by exposing it for five 
minutes to the radiation from a 2,400 candle power quartz mercury vapor burner 
at a distance of 12 cm. A tapeworm, Taenia serrata, about 40 cm. in length, 
was washed in tap water, rinsed in distilled water, and introduced into 10 cc. 
of the solution. Another tapeworm of about the same size was selected and 
one electrode from the secondary of a large induction coil was placed near its 
anterior end while the other electrode was moved back and forth over the 
anterior half of the parasite until no response to stimulation was obtained from 
this portion. In this manner the anterior part of the tapeworm was killed with- 
out breaking the cuticle. A third worm of similar size was selected and the 
entire worm killed by means of induction shocks. These worms were placed 
in vessels containing 10 c.c. of the activated pancreatic juice. The three vessels 
containing the worms were allowed to stand at room temperature for twelve 


Fig. 2—A, uninjured roundworm. B and C, undigested halves of two worms, 
the dead halves having been digested. 


hours. At the end of this time the uninjured worm and the uninjured half of 
the other worm were stimulated by means of weak induction shocks. It was 
found that they were alive. These solutions were removed and 10 c.c. of fresh 
sterilized juice introduced into each vessel. At the end of the second twelve- 
hour period the anterior portion, which had been killed with induction 
shocks, as well as the entire worm which had been killed in the same manner 
had begun to be digested. After introducing into each vessel 10 cc. of fresh 
juice the worms were permitted to stand for a third twelve-hour period. Thus 
the parasites were exposed to the action of the trypsin for thirty-six hours. 
Figure 1 shows the condition of the parasites at this time. A is the uninjured 
tapeworm; A’, a Mett’s tube containing gelatin colored with Congo red which 
was placed simultaneously with the worm in the pancreatic juice in order to give 
an idea of the strength of the trypsin. The dark portion of the tube represents 


182 THE JOURNAL OF PARASITOLOGY 


the undigested gelatin and the light the empty tube from which the gelatin 
was digested. B is the worm the anterior part of which was killed with induc- 
tion shocks, B’, its accompanying Mett’s tube. C”’ is the tube which was in the 
solution with the dead worm C. It may be seen that no portion of the normal 
worm A was digested, that the dead portion of B was completely digested as 
was also the dead worm C. 

Similar experiments were carried out using roundworms. Halves of round- 
worms were killed by means of induction shocks and these together with an 
uninjured worm were introduced into 15 c.c. of activated pancreatic juice, steril- 
ized by ultra violet. The vessel containing the juice and the worms was placed 
in a thermostat at 38 C. At the end of ten hours the solution was replaced 
by 15 c.c. of fresh juice. At this time digestion of the dead portions had begun. 
The uninjured worm and the uninjured portions of the other two were still 
alive. At the end of the second ten-hour period the dead portions of the worms 
were almost completely digested. The juice was again changed and at the 
end of the third ten-hour period the uninjured portions were completely 
digested. A photograph of the worms was taken at this time (Figure 2) ee 
is the uninjured worm; B and C, the undigested halves of the two worms, the 
dead halves having been digested. 


Fig. 3—a, pipette closed with stopper; b, oneway valve; c, segment of round 
worm; d, platinum mesh; e, thin rubber and ligature. 


The experiments now to be described were devised to show that the unin- 
jured parts as well as the uninjured worms were not digested because of the 
protection afforded by the oxidative processes going on in them. Two seg- 
ments, each 5 cm. in length, were cut from a roundworm. Into the lumen 
of one segment (Fig. 3, c) was introduced a cylindrical piece of platinum 
mesh (d) previously covered with platinum black. Around one end of the 
segment was wrapped a narrow strip of thin rubber (e) about which a ligature 
was tied thus closing this end of the segment. A pipette (a) was inserted into 
the open end. This was held in position by means of a ligature. The segment 
was filled with hydrogen peroxid through the pipette, the pipette stoppered and 
a one-way escape valve (b) arranged so that the oxygen liberated from the 
hydrogen peroxid by platinum black could not escape from the segment through 
the pipette until the pressure reached approximately 25 mm. of mercury. The 
pressure arising from the liberated oxygen forced it through the body wall of 
the roundworm. In this manner all parts of the roundworm were exposed to 
oxygen presumably in a nascent state. At this stage of the experiment the 
segment of the worm was dead and the only processes going on within it in 


PRGLECTION OF PARASITES 183 


any way comparable to any of the living processes, was the artificial oxidative 
process. One end of the other segment cut from the same roundworm was 
ligatured and the segment filled with a solution made by decomposing hydrogen 
peroxid with platinum black. The other end was closed by a ligature and the 
preparation introduced into the activated pancreatic juice along with the other 
preparation. The vessel containing the preparations was placed in a thermo- 
stat at 38 C. and allowed to remain for forty-eight hours. At intervals of 
two hours fresh hydrogen peroxid was introduced into the segment into which 
the pipette was tied. At the end of twenty-four hours the pancreatic juice was 
removed from the vessel and fresh pancreatic juice added. At the end of forty- 
eight hours there was very little if any indication of digestion in the segment 
which was permeated by oxygen while the other segment was digested. The 
conclusion is drawn that nascent oxygen prevented the segment of the worm 
from being digested by rendering inactive the enzyme solution in contact with it. 


SUMMARY 


Tapeworms and roundworms from the intestine of the dog are 
not digested when introduced into activated pancreatic juice so long 
as they remain alive but are digested when dead. If any part of 
them be killed this part is digested. 

A dead roundworm which is ordinarily digested when introduced 
into activated pancreatic juice, can be prevented from being digested 
by keeping the dead body wall constantly permeated with nascent 
exygen. 

The oxidative processes of the living parasites enable them to 
withstand the action of the digestive juices by oxidizing the enzyme 
solution immediately in contact with them. 


LITERATURE CITED 


Lillie, R. S.: On the Oxidative Properties of the Cell-Nucleus. Amer. Jour. 
Physiol., 1902, 7, 412-421. 

Burge, W. E., and E. L.: The Role of Nascent Oxygen in Regulating the 
Activities of Enzymes in Animals and Plants. Amer. Jour. Physiol., 1914, 34, 
140-148. 


PARASITES OF THE AMERICAN MUSKRAT 
CHIBER ~~ ZIBETHICUS)* 


FRANKLIN D. BARKER 
Professor of Parasitology, the University of, Nebraska 


In previous papers! the finding of a varied and abundant parasitic 
fauna in muskrats in Nebraska was announced, and attention was 
called to the fact that with the exception of a brief note by Leidy* 
there are no references to or descriptions of the parasites of the 
muskrat. Those papers reported the finding of seven new species of 
trematodes, one new species of cestode, and two new species of 
nematodes. In more recent investigations, two additional species of 
trematodes, one species of cestode and one species of nematode have 
been found. 

A recent appeal to American helminthologists in the JoURNAL OF 
ParasiToLocy by Prof. Al. Mrazek further emphasizes the lack of 
information concerning the parasites of the muskrat and the desira- 
bility of more extensive data. For these reasons it has seemed advis- 
able to publish at once this preliminary description of the parasites 
which we have found in American muskrats and later the more 
detailed descriptions. 

The forms recorded by others are the following: 

Leidy? mentions finding a number of trematodes in the small intes- 
tine of the muskrat which he placed in Echinostomum echinatum 
Zeder. He also found in the muskrat two specimens of a trematode 
which he ‘says “appear to belong to Amphistomum subtriquetrum 
Rud.” We question the correctness of the diagnosis of this trema- 
tode and suspect that they were specimens belonging to the new 
genus and species Wardius zibethicus. 

Dr. B. H. Ransom reports an unidentified species of Filaria from 
the muskrat in the collection of the Bureau of Animal Industry, 
Washington, D. C. 


* Contributions from the Zoological Laboratory of the University of Nebraska, 
No. 113. 


1. Barker, F. D., and Laughlin, J. W.: A new species of trematode from the 
muskrat, Tr. Am. Micr. Soc., 1911, 30, 261-274. Barker, F. D.: The Parasites 
of the Muskrat, Science, 1913, n. s., 37, 1268. 


2. Leidy, Joseph: On the Trematodes’ of the Muskrat, Proc. Acad. Nat. Sci., 
Phila., 1888, 40, 126-127. 


PARASITES OF AMERICAN MUSKRAT 185 
The forms which we have discovered are as follows: 


TREMATODES 


Echinostomum coalitum Barker and Beaver, sp. nov.* (Plate 1, 
Pap. 1). 

Twenty-two specimens of an unusually large trematode were found 
among several hundred specimens of different species of trematodes 
in the intestines of forty-six muskrats. The condensed description 
of this species based on the specimens obtained is as follows: 

Body much elongated, flattened dorso-ventrally, tapering posteriorly, 
slightly tapering anteriorly. When alive, color reddish or creamy, 
body very flabby. Length 22 to 30 mm., width at level of ovary 
i.5 to 2.3 mm., at level of acetabulum 1 to 1.4 mm. Anterior part 
of body covered with minute spines. Well-defined reniform collar 
surrounds oral sucker. Collar has wide shallow or deep narrow 
indentation in posterior edge of ventral surface and bears 35 spines 
arranged in single or slightly alternate rows, 25 large spines on rim 
and 5 smaller spines on each lappet. Oral sucker circular, terminal, 
0.37 to 0.46 mm. in diameter. Acetabulum at level of second anterior 
sixth of body, pouch like, strongly muscular, 1.37 to 1.60 mm. long 
by 1.12 to 1.32 mm. wide. Opening of sucker circular, very large, 
0.72 mm. in diameter. Mouth and pharynx separated by tubular non- 
muscular prepharynx, 0.2 to 0.3 mm. long. Esophagus 1.03 to 3.2 
mm. long. Intestinal ceca tubular, slightly undulating, increasing 
in caliber toward posterior end of body where they end_ blindly. 
Testes close together in median plane, at third fourth of body, one 
testis directly behind other; elliptical; anterior testis entire to four- 
lobed, posterior with smooth or undulating margin. Cirrus pouch large, 
gourd-shaped, with base to right or left at level of anterior third of 
acetabulum. Cirrus pouch encloses tubular, U-shaped seminal vesicle, 
voluminous granular prostate gland and large muscular-walled cirrus. 
Genital pore a little anterior to anterior margin of acetabulum. 

Ovary ovoid, margin smooth or undulating, transverse, median, in 
anterior part of posterior half of body. Shell gland well defined, 
posterior to ovary and slightly larger than it. Seminal receptacle and 
Laurer’s canal not evident. Yolk glands voluminous, of small spher- 
ical follicles, masses continuous, in lateral areas, extending from 
slightly caudad to acetabulum to extreme posterior end of body where 
they coalesce in the median plane, completely filling body posterior 
to testes. Transverse vitelline ducts and reservoir present at level 


3. Abstract of unpublished research by Franklin D. Barker and Chester A. 
Beaver. 


EXPLANATION OF PLA®ES 


Ail drawings were made with a camera lucida from original specimens. 
The degree of magnification is indicated by a vertical line 1 mm. in length at 
the side of each figure. 


ABBREVIATIONS 
A D, Adhesive disc P S, Posterior sucker 
Ac, Acetabulum S} Sucker 
B C, Bursa copulatrix S G, Shell gland 
C P, Cirrus pouch S R, Seminal receptacle 
Cr Cissus S V, Seminal vesicle 
Es, Esophagus TS Gestis” 
Ex, Excretory reservoir Ut, Uterus 
G P, Genital pore Va, Vagina 
G Pa, Genital papilla V D, Vas deferens 
L C, Laurer’s Canal V G, Vitelline glands 


Ov, Ovary V R, Vitelline reservoir 


F 


PEATE 1 


Fig. 1.—Echinostomum coalitum Barker and Beaver, ventral view, specimen 
slightly compressed. 


Fig. 2—Echinostomum coalitum, anterior end enlarged to show cirrus pouch 
and contents. 


Fig. 3.—Echinoparyphium contiguum Barker and Bastron, ventral view, 
specimen compressed. 


Fig. 4—Echinostomum callawayensis Barker and Noll, ventral view, specimen 
compressed. 


Fig. 5—Notocotyle quinqueseriale Barker and Laughlin, ventral view. 
Fig. 6.—Catatropis filamentis Barker, ventral view. 


ar. 


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Pye 
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Fig. 1—Hemistomum craterum Barker and Noll, ventral view. 


Fig. 2—Plagiorchis proximus Barker, ventral view. 
Fig. 3—Wardius zibethicus Barker and East, ventral view, specimen compressed. 
Fig. 4.—Scolex of Hymenolepis evaginata Barker and Andrews. 
Fig. 5—Hook of Hymenolepis evaginata. 
Fig. 6—Mature proglottid of Hymenolepis evaginata. 
Fig. 7.—Gravid proglottid of Hymenolepis evaginata. 
Fig. 8—Scolex of Anomotaenia telescopica Barker and Andrews. 


Fig. 9.—Mature proglottid of Anomotaenia telescopica, reconstruction from 
frontal sections. 
Fig. 10—Gravid proglottid of Anomotaenia telescopica. 


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PARASITES OF AMERICAN MUSKRAT 187 


of shell gland. Uterus median with densely coiled transverse tubes 
extending from anterior testis to genital pore. 

Eggs numerous, oval, light brownish color, 0.104 to 0.108 mm. by 
0.067 to 0.070 mm. Lids small, opercular rim absent. Excretory 
reservoir tubular, in median plane of posterior part of body, forming 
a large bulb-like reservoir at extremity of body; excretory pore ter- 
minal, median. 

Found in duodenum of host. 

Echinoparyphium contiguum Barker and Bastron, sp. nov.* (Plate 
a, Fig... 3): 

Body spindle- or boat-shaped, flattened dorso-ventrally, anterior end 
tapering, posterior end bluntly rounded. Length 3.3 to 4.3 mm.; 
width 0.57 to 0.70 mm. at level of acetabulum. Oral sucker almost 
surrounded by well-defined collar with ventral median incision. Collar 
has 37 spines arranged in alternate rows of 14 oral and 15 aboral 
spines on rim and one set of 4 on each ventral flap or lappet. Cuticula 
smooth, without spines. Oral sucker subterminal, 0.12 to 0.16 mm. 
by 0.09 to 0.14 mm. 

Large circular muscular acetabulum, 0.45 to 0.57 mm. in diameter 
at middle of anterior half of body. Oval muscular pharynx separated 
from mouth by short prepharyngeal tube. Wide, thin-walled esopha- 
gus extending from pharynx to level of acetabulum where it bifur- 
cates; intestinal ceca extend straight to posterior end of body and 
end blindly. 

Ovary small, ovoid, 0.16 to 0.19 mm. by 0.14 to 0.15 mm. in 
middle of body, slightly to left of median line. Shell gland diffuse, 
without definite outline, at. level of ovary and to right of median 
line. Laurer’s canal present. Seminal receptacle not evident. Testes 
very large, in anterior part of posterior half of body, median, one 
directly behind the other. Uterine coils loose, occupying intercecal 
zone between shell gland and acetabulum. Vagina opens with cirrus 
at genital pore just posterior to bifurcation of esophagus. Cirrus 
pouch club-shaped, extending from genital pore obliquely caudad, 
dextral and dorsal to acetabulum. Its base at level of middle of 
acetabulum. Large tubular seminal vesicle, granular prostate gland, 
and muscular cirrus lie within cirrus pouch. 

Vitelline glands coarsely acinous, extending in continuous lateral 
masses from acetabulum to extreme posterior end of body. Masses 
more voluminous caudad to posterior testis. Transverse vitelline 
ducts and median vitelline reservoir at level of anterior margin of 
anterior testis. Eggs limited in number, from 30 to 100; oval, 0.096 
to 0.109 mm. in length by 0.068 to 0.070 mm. in width. Lid present. 


4. Extract of unpublished research by Franklin D. Barker and Carl Bastron. 


188 THE JOURNAL (OF; PARASITOLOGY 


Excretory system Y-shaped, lateral arms unite just caudad to 
posterior testis, forming large tubular median reservoir; excretory 
pore median and slightly ventral, at posterior end of body. 

Found in duodenum of host. , 

Echinostomum callawayensis Barker and Noll, sp. nov.’ (Plate 1, 
Fig. 1). 

Body spatulate; anterior end tapering, posterior end_ bluntly 
rounded. Length 4.28 to 6.91 mm.; width 1.04 to 149 mm. Anterior 
end almost entirely surrounded by oval collar-like expansion, 0.34 to 
0.51 mm. wide, having a definite ventral incision. Collar armed with 
double row of alternately arranged spines varying in number from 
37 to 41, 31 to 33 on rim and 2 to 5 on each flap. Length of collar 
spines 0.0385 to 0.056 mm., mid-dorsal spine being smallest. Cuticula 
smooth, without spines. Acetabulum circular, cavity sac-like, mus- 
culature well developed, lying between first and second anterior fourths 
of body. 

Oral sucker 0.08 to 0.16 mm. long by 0.12 to 0.17 mm. wide, 
separated from pharynx by short narrow prepharyngeal tube. Weakly 
developed but wide esophagus bifurcates into narrow ceca which 
broaden posterior to acetabulum and end blindly between posterior 
testis and posterior end of worm. Testes more or less elliptical, lying 
tandem in anterior three-fourths of posterior half of body. Cirrus 
pouch, pear-shaped, containing thick, muscular-walled cirrus, tubular 
somewhat coiled seminal vesicle, and granular prostate gland; pouch 
right or left and anterior to middle of acetabulum. Genital pore right 
or left of median line and anterior to acetabulum. 

Ovary nearly globular, in middle of body right or left of median 
line; large, compact, well-defined, pear-shaped shell gland between 
ovary and anterior testis. Uterine coils compact, almost entirely 
anterior to ovary, filling region between intestinal ceca. Laurer’s canal 
present ; seminal receptacle not found. Eggs numerous, straw colored, 
oval, lid small, without opercular rim; length 0.0805 to 0.1015 mm., 
width 0.042 to 0.063 mm. Vitelline glands coarsely acinous, extending 
from posterior border of acetabulum in continuous lateral masses to 
posterior end of worm; posterior to testis vitelline glands extend 
toward median line but do not coalesce. Transverse vitelline duct and 
reservoir at level of anterior margin of anterior testis. 

Excretory system Y-shaped, with slender median reservoir ; excre- 
tory pore in median line at posterior end of worm. 

Found in duodenum of host. 


5. Extract of unpublished research by Franklin D. Barker and William C. 
Noll. 


PARASITES OF AMERICAN MUSKRAT 189 


Echinostomum armigerum Barker and Irvine, sp. nov.® (Text 
Fig. A). 

Body elliptical, somewhat flattened dorsoventrally, anterior end 
slightly tapering, posterior end wider and more rounding. Length 
9.4 to 12.4 mm.; width 1.2 to 1.8 mm. When alive pinkish gray color. 
Oral sucker almost completely surrounded by well-developed collar 
bearing 37 chitinous spines arranged in three sets, 27 around rim and 
5 on each ventral point of collar. Collar spines vary in length from 
0.061 to 0.094 mm., those on points of collar being smallest. Well 
marked median ventral break in collar. Anterior third of body cov- 
ered by small spines 0.030 mm. long. Acetabulum prominent, pouch- 
like at juncture of anterior and middle thirds of body. 


Fig. A.—Anterior end of Echinostomum armigerum: Bs, body spinelets; 
C, collar; Cs, collar spines; Es, esophagus; Ph, pharynx. 


Digestive tract well developed ; intestinal ceca somewhat undulating 
and rather narrow, ending blindly in extreme posterior end of worm. 
Testes quadrate to triangular, irregularly lobed, lying tandem and 
close together between middle and posterior thirds of body. Cirrus 
pouch pear shaped, surrounding large thick walled cirrus, and tubular 
somewhat coiled seminal vesicle, at level of anterior margin of 
acetabulum. Genital pore median between anterior margin of acetab- 
ulum and transverse arms of ceca. 

Ovary pear-shaped, anterior to testes, median, transverse. Well- 
defined shell gland, slightly larger than the ovary, between anterior 


6. Extract of unpublished research by Franklin D. Barker and Robert S. 
Irvine. 


190 TE HOORNALY OF VPARASIT OLOGY, 


testis and ovary, slightly to one side. Laurer’s canal and seminal 
receptacle not found. Uterine coils fairly compact, in transverse coils 
for most part anterior to ovary in median field. Eggs numerous, straw- 
colored, ovoid, operculum small and without opercular rim; size 0.084 
to 0.105 mm. by 0.057 to 0.066 mm. 

Vitelline glands coarsely acinous, extending in continuous masses, 
irom acetabulum, in lateral fields, to posterior end of worm. Trans- 
verse vitelline ducts and reservoir at level of shell gland. Excretory 
system two lateral vessels which unite in region of posterior third 
of body and form slender median excretory reservoir; excretory pore 
in median line at posterior end of worm. 

Found in duodenum of host. 

Notocotyle quinqueseriale Barker and Laughlin, (Plate 1, Fig. 5). 

Characters in general like those of genus. Ventral surface pro- 
vided with five distinct longitudinal rows of wart-like papillae extend- 
ing from anterior to posterior end, with 16 to 18 papillae in each 
row. Cuticula without spines. Length of body, 2.5 to 4.0 mm.; 
width 0.66 to 1.33 mm. Cirrus pouch elongated, extending from 
posterior margin of oral sucker to middle third of body. Vagina as 
long as cirrus pouch. Eggs light straw color, oval, with long polar 
filament at each end; 0.019 to 0.021 mm. long, 0.01 to 0.013 mm 
wide. Polar lid present. Most abundant parasite found; generally 
occurs in cecum. 

Catatropis fimbriata Barker, sp. nov." (Plate 1, Fig. 6). 

Body thin, flat, gradually tapering anteriorly. Length 2.2 to 3.3 
mm., width at level of testes 0.56 to 0.70 mm. Anterior half of body 
covered with minute needle-like spines in definite oblique rows. Three 
longitudinal rows of flattened circular papillae on ventral surface; 12 
to 13 papillae in each row. Oral sucker, sub-terminal, oval 0.079 to 
0.099 mm. wide, 0.066 to 0.092 mm. long. Pharynx absent; esophagus 
0.105 to 0.132 mm. long; intestinal ceca undulating, external to uterine 
coils, internal to testes, end blindly in posterior end of worm. Testes 
opposite, at same level in posterior fifth or sixth of body, weakly two- 
to four-lobed ; 0.198 to 0.257 mm. long, 0.132 to 0.151 mm. wide; vas 
deferens prominent, median, extends from shell gland to base of 
cirrus pouch; cirrus pouch tubular, greatly elongated, extends from 
level of intestinal bifurcation caudad to level of middle third of body. 
Seminal vesicle coiled at base of and almost entirely outside of cirrus 
pouch. Prostate gland and muscular cirrus covered with papillae 
within pouch. Ovary between testes, globular or oval, margin undulat- 
ing 0.132 mm. long by 0.105 to 0.112 mm. wide. Uterine coils trans- 
verse, numerous compact, in intercecal zone. Vagina straight, walls 


7. Abstract of unpublished research by Franklin D. Barker. 


PARASITES OF AMERICAN MUSKRAT 191 


quite muscular, as long as cirrus pouch. Genital pore ventral, median, 
just caudad to intestinal bifurcation. Shell gland, compact, definite, 
ovoid, immediately anterior to and a little larger than ovary. 

Vitelline glands, lateral in extracecal zone in posterior half of 
body, extending from middle of body caudad to level of testes, 12 
to 15 rather definite, irregular acini on each side. Excretory canal 
tubular, undulating, extends in median line from ovary to posterior end 
of body. Eggs elongated, oval, 0.020 to 0.022 mm. long, 0.011 mm. 
wide; shell thick, with lid and long polar filament at each end, 0.084 
to 0.098 mm. long. 

Found in duodenum of host. 

Hemistomum craterum Barker and Noll, sp. nov.® (Plate II, Fig. 1). 

Body divided into cephalic and caudal regions; cephalic region 
thin, flat, wide, anterior portion tapering, lateral margins turn ventrad 
and mesad one fifth width of region; caudal region thick, rounding, 
conical. Length of entire worm 0.75 to 1.89 mm. Length of cephalic 
region 0.62 to 0.79 mm., width 0.41 to 0.49 mm.; length of caudal 
region 0.28 to 0.47 mm., width 0.20 to 0.36 mm. 

Body spines not evident. Oral sucker muscular subterminal, nearly 
circular, 0.075 to 0.094 mm. in diameter. Acetabulum at posterior 
margin of anterior half of cephalic region, circular, 0.075 mm. in 
diameter. Adhesive disk large, flattened cone with crater-like top, 
muscular without papillae ; median in anterior portion of posterior half 
of cephalic region. Frequently overlaps acetabulum. Size 0.19 to 
0.22 mm. in diameter. 

Pharynx oval, 0.07 mm. long by 0.073 mm. wide. Esophagus nar- 
row, straight, 0.06 mm. long. Intestinal ceca narrow, tubular, undulat- 
ing, terminating blindly in posterior end of caudal region. Ovary at 
junction of body regions to right of median line. Globular, margins 
smooth 0.07 mm. in diameter. Shell gland diffuse, in same plane but 
on opposite side from ovary. 

Uterus, winding turns to left then caudad to bursa copulatrix, 
which is dorsal and subterminal in posterior end of worm. Vitelline 
glands voluminous globular acini, filling posterior two thirds of cephalic 
region. Testes two, globular or oval, entire or slightly lobed at about 
middle level of caudal region on either side of median line, slightly 
oblique. Twice as large as ovary. Seminal vesicle, large, winding 
tube slightly to left of median line between testes; opens into bursa. 
Genital pore slit-like, dorsal, median, subterminal, at posterior end 
of worm. Eggs, large, oval, few, one to three; thin shell, small oper- 
culum, size 0.11 by 0.07 mm. 


8. Abstract of unpublished research by Franklin D. Barker and William C. 
Noll. 


192 THE JOURNAL OF PARASITOLOGY 


Found in duodenum and cecum of host; only in one out of forty-six 
muskrats examined. ; 

Plagiorchis proximus Barker, sp. nov.® (Plate II, Fig. 2). 

Body plump, oval, tapering anteriorly, bluntly rounding posteriorly. 
Color creamy, opaque. Minute spinelets cover anterior two thirds of 
body. Length 1.32 to 1.98 mm., width at level of anterior testis 0.49 
to 0.66 mm. Oral sucker muscular, terminal, 0.085 to 0.125 mm. 
long by 0.105 to 0.115 mm. wide. Pharynx immediately posterior to 
oral sucker, 0.035 to 0.05 mm. long by 0.045 to 0.055 mm. wide. 
Esophagus as long as pharynx. Intestinal ceca, simple, straight, extend 
almost to posterior end of body. Acetabulum, between first and second 
fourths of body; muscular, circular, 0.065 to 0.11 mm. long by 0.075 
to 0.105 mm. wide. Ovary, globular to oval, margins smooth, immedi- 
ately posterior to acetabulum and to right of median line. Margin 
separated by width of cirrus pouch, or touches posterior margin of 
acetabulum. Size 0.095 to 0.145 mm. long by 0.10 to 0.11 mm. wide. 
Uterine coils winding, descending limb passes caudad from ovary 
between testes filling posterior end of body, ascending limb passes 
between testes cephalad to genital pore; coils overlap testes but do not 
overlap intestinal ceca. Eggs very numerous. Vitelline glands volu- 
minous, coarse globular acini lateral and partly dorsal and ventral, 
extend uninterrupted from slightly anterior to acetabulum to extreme 
posterior end where they tend to fuse; glands overlap and obscure 
intestinal ceca; shell gland, diffuse, posterior and to left of ovary. 
Seminal receptacle and Laurer’s canal not evident. Testes, globular, 
margins smooth, in anterior portion of posterior half of body, one 
obliquely behind the other, slightly separated. Testes measure 0.125 
to 0.160 mm. long by 0.120 to 0.150 mm. wide. Cirrus pouch, narrow, 
elongated, tubular; base just posterior to acetabulum and to left of 
median line ; pouch turns transversely to right then cephalad dorsal and 
to right of acetabulum to the genital pore. Genital pore in median 
plane just anterior to acetabulum. Eggs numerous, straw color, oper- 
culum, with rim present, opercular end broad, opposite end taper- 
ing. Size 0.032 to 0.0378 mm. long by 0.020 to 0.024 mm. wide. 

Found in duodenum of host. 

Wardius zibethicus Barker and East, Gen. et sp. nov.° (Plate II, 
Fig. 3). 

Large thick worms, 4 to 13 mm. long by 1 to 4.5 mm. wide; body 
broadly oblanceolate; anterior end tapering and bluntly conical, pos- 
terior end broader and rounded. Cuticula smooth without spines or 


9, Abstract of unpublished research by Franklin D. Barker. 


10. Abstract from unpublished research by Franklin D, Barker and Anna M. 
East. 


PARASITES OF AMERICAN MUSKRAT 193 


wart-like projections. Oral sucker absent; large muscular, cup-shaped 
sucker, posterior, ventral and subterminal; antero-posterior diameter 
1.116 to 2.79 mm., transverse diameter 1.116 to 2.294 mm.; opening 
of sucker 0.3 to 1.55 mm. in diameter. Small, terminal mouth leads 
directly into muscular, elongated, cup-shaped pharynx (or oral 
sucker), size 0.434 to 0.992 mm. by 0.434 to 0.992 mm. pharynx with 
two dorsal, postero-lateral pockets often as large as pharynx; 0.45 to 
1.08 mm. in length by 0.45 to 0.99 mm. in breadth. Pharynx leads 
into well-developed simple esophagus, without muscular thickenings ; 
0.62 to 2.17 mm. long and 0.186 to 0.30 mm. wide, bifurcating at level 
of first and second fourths of body; intestinal ceca sinuous, with 
numerous short lateral pockets, terminating blindly at level of anterior 
margin of posterior sucker. 

Two testes weakly, but not regularly lobed, close together in 
tandem position in middle third of body. Testes vary from orbicular 
to transversely elliptical, 0.496 to 1.736 mm. in length by 0.496 to 
2.294 mm. in width. 

Male genital tract terminates in much convoluted and distended 
vesicula seminalis followed by slightly convoluted pars musculosa and 
pars prostatica surrounded by prostate gland. Short ductus ejacu- 
latorius opens at base of genital papilla, ventral, right or left of median 
plane just posterior to intestinal bifurcation and slightly anterior to 
anterior margin of anterior testis; hermaphroditic duct and genital 
sucker absent. Ovary median, at level of posterior third of body, 
orbicular or transversely oval with smooth or undulating margin. 
Shell gland somewhat diffuse, right or left of, and posterior to ovary. 
Laurer’s canal right or left. and posterior to ovary; opening dorsal, 
median, slightly anterior to posterior sucker. Vitelline glands small 
globular acini, continuous, extending from level of pharynx to middle 
of posterior sucker, almost entirely outside of intestinal ceca. Two 
transverse vitelline ducts and prominent yolk reservoir at level of shell 
gland. Uterus in median plane, anterior to the ovary. Coils trans- 
verse, loose to compact. Metraterm opens at base of genital papilla 
through common genital pore. 

Eggs, elongated, oval, numerous; opercular end tapering, 0.016 
tc 0.019 mm. by 0.009 to 0.014 mm. Operculum small, opercular rim 
absent. Excretory system complex consisting of two longitudinal 
canals, mesal of intestinal ceca, with numerous anastomizing laterals, 
extending from anterior end to posterior sucker where they empty 
into large vesicular reservoir dorsal and in part posterior to anterior 
margin of posterior sucker.. Excretory pore dorsal, median at level 
of anterior margin of posterior sucker. 

Generally found in cecum of host. 


194 THE JOURNAL. OF PARASITOLOGY 


CESTODES 


Hymenolepis evaginata Barker and Andrews, sp. nov." (Plate II, 
Figs. 4, 5,6, 7). 

Worms 20 to 40 cm. long, 300 to 900 proglottids. In living worm 
posterior three centimeters greatly contracted, thick, rigid, opaque, 
anterior portion of body abruptly becomes thin, flabby, transparent. 
Proglottids four to eight times wider than long. Gravid posterior 
proglottids 2 to 3 mm. by 0.36 mm., anterior proglottids 0.15 to 0.30 
mm. by 0.045 mm. Lateral edges project slightly. Genital pores uni- 
lateral in middle of proglottid. Scolex well developed, inverted pear- 
shaped, 0.33 mm. wide; four muscular circular suckers present, 0.09 
to 0.11 mm. in diameter. Rostellum elongated, retractile, pestle-shaped, 
armed with single row of ten comparatively large hammer-shaped 
hooks, 0.007 mm. long by 0.004 mm. wide. Three testes, large, 
globular; one on one side and two, one obliquely anterior to other, 
cn opposite side. Cirrus elongated, muscular, posterior to vagina. 
Ovary transversely elongated, bilobed, median, posterior; vitelline 
gland, transversely elongated, median, behind ovary. Shell gland oval, 
median, anterior to vitelline gland. Mesal end of vagina swollen to 
form seminal receptacle anterior to ovary. Vagina opens anterior to 
cirrus. Gravid uterus transversely elongated, sac-like, anterior and 
posterior margins lobulated, partitions absent. Eggs oval, thin shell, 
0.0206 by 0.0162 mm. 

Found in duodenum of host. 

Anomotaenia telescopica Barker and Andrews, sp. nov.” (Plate II, 
Figs. 8, 9, 10). 

Preserved specimens 115 to 130 mm. long, with 600 to 700 
proglottids. Body heavy, rugged, opaque, proglottids markedly tele- 
scoped, edges serrated, mature proglottids four to five times wider 
than long, gravid proglottids three to four times longer than wide. 
Mature proglottids 1.1 mm. wide; 0.5 mm. long, 0.17 mm. thick. 
Gravid proglottids 1.5 mm. long by 0.5 mm. wide. Genital pores 
irregularly alternate. Scolex well developed 0.17 mm. wide with four 
muscular, circular, cup-shaped suckers. Rostellum strongly developed, 
wide, armed with double row of forty-eight alternately arranged, 
elongated hooks. Inner row of twenty-four hooks, 0.057 mm. long; 
outer row of twenty-four hooks 0.047 mm. long. 

Testes limited in number, in lateral and posterior regions of mature 
proglottids. Cirrus pouch short, muscular, anterior to vagina. Ovary 
transversely elongated, weakly bilobed, median, posterior. Vitelline 
gland compact elongated, median, posterior to ovary. Shell gland 


11. Abstract of unpublished research by Franklin D. Barker and Mitchell 
Andrews. 


12. Abstract of unpublished research by Franklin D. Barker and Mitchell 
Andrews. 


PARASITES OF AMERICAN MUSKRAT 195 


oval, median, anterior to vitelline gland. Seminal receptacle prominent, 
sac-like, anterior to ovary. Vagina elongated, muscular. Uterus, 
sac- or pouch-like in posterior portion of gravid proglottids, without 
median stem or lateral branches. Eggs spherical, 0.013 mm. in 
diameter, shell thick. 

Found in duodenum of host. 


NEMATODA 
Trichuris opaca Barker and Noyes, sp. nov.’® (Text Fig. B). 


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Fig. B, 1—Trichuris opaca, male. Fig. 2—Trichuris opaca, posterior end of 
male. Fig. 3—Trichuris opaca, female. A, anus; B R, body region; E R, eso- 
phageal region; Es, esophagus; /, intestine; S, Spicule sheath; Sp, spicule; 
S V, seminal vesicle; J, testis; Ut, uterus; VY, vulva. 


13. Abstract from unpublished research by Franklin D. Barker and Bessie 
Noyes. 


196 THE JOURNAL. OF PARASITOLOGY 


Body cylindrical, stiff, opaque, divided into long slender esophageal 
region and shorter, thicker body region. Anterior portion attenuated, 
tapering, rounded; posterior blunt, rounded; anus a little subterminal. 

Male: 22 to 28 mm. long; esophageal region 13 to 19 mm. long, 
0.06 to 0.08 mm. wide; body region 7 to 9 mm. long, 0.14 to 0.16 
mm. wide. Posterior end rolled into spiral. Spicule 2 mm. long by 
0.017 mm. broad surrounded by sheath covered by minute blunt 
spinelets ; sheath when evaginated 0.18 mm. long by 0.07 mm. broad. 

Female: 28 to 30 mm. long; esophageal region 18 to 19 mm. long, 
0.06 to 0.07 mm. wide; body region 10 to 11.1 mm. long, 0.23 to 0.25 
mm. wide. Posterior portion slightly curved. Vulva between first 
and second anterior elevenths of body region. Anus nearly terminal. 

Found in duodenum of host. 


Fig. C, 1—Trichostrongulus fiberius, posterior end of male. Fig. 2—Tricho- 
strongylus fiberius, female. A, anus; D L, dorsal lobe; D L R, dorso-lateral 
lobe; J, intestine; L L, lateral lobe; L R, lateral ray; Ov, ovary; Sp, spicule; 
Ut, uterus; V, vulva; V L, ventro-lateral ray. 


Trichostrongylus fiberius Barker and Noyes, sp. nov.t* (Text 
Pig. C). 

Body thread-like, anterior region greatly attenuated, body gradually 
widens toward posterior end. Buccal cavity and teeth absent. 

Male: 2.8 mm. long; width just posterior to mouth 0.013 mm., 
anterior to bursa 0.09 mm. Bursa with two wide lateral lobes and 


14. Abstract from unpublished research by Franklin D. Barker and Bessie 
Noyes. ; 


PARASITES OF AMERICAN MUSKRAT 197 


narrow dorsal median lobe. Lateral lobes with two wide, blunt, 
lateral rays and one narrow, pointed dorso-lateral and one ventro- 
lateral ray. Spicules short and heavy. 

Female: 4.7 mm. long; width posterior to mouth 0.03 mm., at 
level of vulva, 0.135 mm. Vulva in posterior ninth of body 0.52 mm. 
from end. Anus 0.08 mm. from posterior end. Posterior end slightly 
curved and pointed. Eggs oval, segmented, 0.059 by 0.036 mm., 
shell, thick. 

Found in duodenum and cecum of host. 

Capillaria ransomia Barker and Noyes, sp. nov.'® (Text Fig. D). 

Body capillary, not divided externally into two regions, gradually 
increasing in width in body region. Anal opening subterminal. 


Fig. D, 1—Egg of Capillaria ransomia. Fig. 2——Caudal region of male, 
Capillaria ransomia, lateral view; bm, bursal membrane; sh, spicule sheath; sp, 
spicule. 


Male: 19.6 mm. long, width posterior to mouth 0.01 mm., in 
posterior region 0.032 mm. Posterior end slightly curved; small bursa 
present with two lateral lobes; one spicule, 1.36 mm. long by 0.007 
mm. wide; spicule sheath 0.01 mm. wide. 

Female: 19 mm. long; width posterior to mouth 0.022 mm., pos- 
terior region 0.065 mm. Vulva in anterior fourth of body, 5 mm. 
from anterior end. Eggs with prominent plugs, 0.05 mm. by 0.02 mm. 

Found in duodenum of host. 

It is hoped that these preliminary descriptions will stimulate and 
facilitate further investigations of the parasites of the muskrat in 
other localities. 


15. Abstract from unpublished research by Franklin D. Barker and Bessie 
Noyes. 


GORDIUS LARVAE PARASITIC IN A TREMATORES 


WILLIAM WALTER CorT 
Macalester College, Saint Paul, Minn. 


During the summer of 1914 while carrying on investigations at the ~ 
University of Michigan Biological Station, Douglas Lake, Michigan, 
I collected some trematodes which contained in their parenchyma early 
developmental stages of Gordius larvae. This observation seems worth 
reporting, especially since no record has been found of a trematode 
parasitized by another animal. 

These trematodes, which belong to the species Brachycoelium hos- 
pitale Stafford, were found in the intestines of specimens of the green 
newt (Diemictylus viridescens) from a small beach pool on the north 
side of Douglas Lake. The anatomy of this fluke has been described 
by Stafford (1903:824). The infection of the Douglas Lake newts 
while not particularly heavy is considerably greater than that reported 
dy him. Of nineteen individuals of Diemictylus viridescens examined, 
thirteen were infected with a total of thirty-seven specimens of 
Brachycoelium hospitale, the greatest number in one host being eight. 

The accidental finding of a Gordius larva coiled up in the paren- 
chymatous tissue of one of the trematodes led to further examination. 
In all, sixteen of the trematodes were examined carefully for the pres- 
ence of these larvae. Eight cf them from several different hosts were 
infected, two containing two larvae and the others one each. The 
Gordius larvae were found in various positions: one was next to the 
oral sucker, another just anterior to the ovary, and others near the 
testes or further posteriad among the uterine coils (Fig. 1). 

The Gordius larvae in the trematodes were in a very early stage of 
development, being but little beyond the condition found in fully 
developed eggs. They floated freely in spaces in the parenchymatous 
tissue. No spontaneous movement was noted and there was no indi- 
cation of a cyst. The larvae were coiled very tightly ; the anterior end 
appeared truncated, and the proboscis entirely retracted. The posterior 
extremity was terminated by a short spine (Fig. 2). There was no 
indication that the larvae were continuing their development in the 
tissues of the trematode. 

Early larval stages of the Gordiacea have been found in a large 
variety of aquatic animals. Viilot (1891: 338) states that the “embryo” 
of Gordius aquaticus has been found in the mesenteries of Rana tem- 


* Publication No. 31 from the University of Michigan Biological Station. 


GORDIUS LARVAE PARASITIC IN A TREMATODE 199 


poraria, in aquatic insect larvae (Tanypus, Corethra, Chironomus), in 
the parenchyma of leeches, in the mucous membrane of the intestine of 
fishes, and even in the foot of snails. Which of these are normal hosts 
is a matter of dispute, some authorities favoring the insect larvae and 
some the fishes. The presence of Gordius larvae in trematodes from 
the intestine of the newt is without doubt a case of accidental para- 
sitism, the larvae ingested by the newt having sought to escape the 


Fig. 1—A specimen of Bracliycoelium hospitale containing two Gordius 
larvae (gl). X 28. 


intestinal juices by boring into the trematodes. That the trematode 
can have any normal place in the life-history of Gordius is evidently 
unlikely since the adult trematode finishes its life in the intestine of its 
host and under these conditions the encysted larvae can hardly reach 
a place suited for further development. Probably after hatching from 
the egg Gordius larvae by the use of their extraordinary boring appar- 
atus are able to make their way into almost any aquatic animal. 


vege 
\ 


Fig. 2——Gordius larva in parenchyma of posterior end of fluke shown in 
Figure 1. X 160. 


Many of them wander into places where development stops; but the 
continuation of the species depends on a few of the myriads hatched 
finding some normal host, i. e., one in which complete development is 
possible. The life history thus appears to be only roughly adjusted 
and to lack the precise relations shown by many other parasitic species. 


LITERATURE CITED 
Stafford, J. 1903. Two Distomes from Canadian Urodela. Centralbl. 
Bakteriol. u. Parasit., (1) Orig., 34: 822-830. 
Villot, A. 1891. L’Evolution des Gordiens. Ann. sci. nat., Zool., 11: 329-401. 


SOCIETY PROCEEDINGS 


THE HELMINTHOLOGICAL SOCIETY OF WASHINGTON 


The twenty-fifth regular meeting of the Society was held at the residence 
of Dr. Stiles on March 26, 1915, Dr. Stiles acting as host and Dr. Ransom as 
chairman. 

Dr. Cobb presented some figures of a species of Bunonema, pointing out the 
fact that the large cuticular bosses, which had been described by other workers 
as dorsal or ventral, were really located on the right side of the worm in this 
genus, the animal in consequence being notably asymmetrical. 

Dr. Cobb also gave a demonstration of the workings of the new Bausch 
& Lomb projection apparatus, using the nitrogen-filled, tungsten-filament bulb. 

Dr. Stiles gave a résumé of the sanitary campaign in some parts of the 
southern United States, and pointed out the considerable advantage to be gained 
by methods of civic education as opposed to the use of military and police 
methods. Educational methods work from the inside, and secure cooperation 
without arousing hostility. In actual practice, the greatest reforms accom- 
plished anywhere in the South were accomplished without the arrest of a single 
individual or the imposition of one fine. A striking economic feature of the 
work in Wilmington, North Carolina, was the appropriation of $50,000 by the 
city to be used as a loan fund for the installation of sewer service. Any person 
financially unable to install sewer service could borrow the necessary money 
from the city, the city taking a lien on the property for the loan, and could pay 
the money back in easy instalments, the city charging 6 per cent. interest on 
the loan. 

Dr. Hall presented a paper entitled “A Case of Taenia saginata Presenting 
Structural Abnormalities and Associated with Spurious Parasitism in an Infant.” 

Dr. Ransom exhibited some specimens of trichinae digested out of meat 
exposed three weeks to temperatures of 15, 10 and 5 F., respectively, and for 
comparison some specimens digested out of unfrozen meat. The normal trichinae 
examined at room temperature were seen to be tightly coiled; the esophageal 
cell body was brown in color; its nuclei clear and vesicular, and the reproductive 
cells formed a continuous hyaline mass. Those from meat exposed to 15 F. were 
less tightly coiled; the color of the cell body was less pronounced; the granula- 
tion of the protoplasm of the esophageal cells differed somewhat from normal, and 
in some cases there was a tendency toward dissociation of the reproductive cells. 
Those from meat exposed to 10 F. were loosely coiled, and in many cases had 
assumed the form of a figure 6; the color of the cell body was much paler than 
normal; the nuclei of the esophageal cells were more or less solidified; the pro- 
toplasm of these cells was abnormally granular, and the reproductive cells 
were more or less dissociated, tending toward a spherical form. The larvae 
from meat exposed to 5 F. had assumed the form of a figure 6; the esophageal 
cell body had entirely lost its brown color; the nuclei were solidified or not 
apparent; the protoplasm showed a pronounced abnormal granulation, and the 
reproductive cells were either dissociated or broken down into a granular mass. 
The exact nature of the changes produced by low temperatures is not known, 
but it is evident that the changes become more marked as the temperature 
becomes lower. Possibly there is a separation of colloids which are unable 
after thawing to resume their former relations in the protoplasmic complex. 
The viability of the larvae is materially affected by exposure to low tempera- 
tures. Infections may result after exposure to temperatures of 10 F. and 15 F., 
but none has resulted in numerous trials from the feeding of meat exposed for 


HELMINTHOLOGICAL SOCIETY OF WASHINGTON 201 


three weeks to temperatures of 5 F. and lower. Examined on a warm stage 
most of those exposed to 15 F. are active motile; a smaller proportion of those 
exposed to 10 F. are active, whereas none of those exposed to 5 F. or lower have 
exhibited other than very feeble movements, and only very rarely have 
they shown even the faintest signs of life. 

Maurice C. Hatt, Secretary. 


The twenty-sixth regular meeting of the Society was held at the residence 
of Dr. Ransom on April 22, 1915, Dr. Ransom acting as host and Mr. Crawley 
as chairman. 

Dr. Stiles presented a paper on the parasites of schoolchilren in a Southern 
city. The data were tabulated with regard to race, sex and the presence of sewer 
connections or privy in the home of the pupil. Of 2,448 white children, fecal 
samples were obtained from 776; and of 1,346 negro children, fecal samples were 
obtained from 511. Of the total number of children, 2,448 white and 1,346 
negro, 20 per cent. of the white children and 76 per cent. of the negro children 
were from homes with privies. A higher percentage of samples was obtained 
from negro children (38 per cent.) than from white children (32 per cent.), 
showing that it is possible to obtain the cooperation of the negroes to a notable 
extent, if the cooperation is sought in the right manner. The poorer showing 
of the white children is to be explained in part by the natural diffidence dis- 
played by white girls, samples being obtained from only 26 per cent. of these. 

Of 776 white pupils, 36.73 per cent. had intestinal parasites, and of 511 
negroes, 49.12 per cent. had intestinal parasites. It is evident, then, that the 
negroes, coming from homes usually provided with privies (76 per cent.) and 
seldom with sewer connections, have a higher infestation than white children 
coming from homes usually provided with sewer connections and seldom pro- 
vided with privies (20 per cent.). However, the percentage of infestation among 
negro boys and girls was practically identical, indicating a similar degree of 
cleanliness or lack of it for both sexes, whereas the percentage of infestation 
among white boys was higher than among white girls, indicating a greater 
degree of cleanliness among the white girls as compared with white boys. The 
white boys from homes provided with sewers showed a greater degree of infes- 
tation than white girls from homes having only privies. It may be surmised 
that this follows not only from the greater cleanliness of the white girls, but a 
more roving disposition on the: part of the white boy. The white boys from 
home having privies showed a greater infestation than negro boys and girls 
from similar homes, but in connection with these figures it should be noted that 
the number of white boys in this category is very small and the resultant per- 
centage less apt to be reliable or representative. 

Parasites were considered in two groups: 1. Those that could only be acquired 
as the result of ingesting human feces in some way, and including Entameba, 
Lamblia, Trichomonas, Oxyuris, Ascaris and Trichuris. 2. Those that might be 
acquired in some other way, including Hymenolepis and Necator. 

Of the 776 white children, 28 per cent., and of 511 negro children, 48 per cent., 
were infested with parasites of the first group, the infestation for each parasite 
being as follows: Entameba coli, 8.7 per cent. of whites and 11.9 per cent. of 
negroes; Lamblia, 12.7 per cent. of whites and 6.5 per cent. of negroes; Tricho- 
monas, only 5 infestations, all in whites, 0.6 per cent.; Ascaris lumbricoides, 7.5 
per cent. of whites and 27.9 per cent. of negroes; Oxyurias vermicularis, only 3 
infestations, all in whites, 0.4 per cent.; Trichuris trichiura, 1.3 of whites and 
11.5 per cent. of negroes. 

Of the same children, 10.9 per cent. of the white children and 3.5 per cent. of 
the negroes were infested with parasites of the second group, the infestation for 
each parasite being as follows: Hymenolepis nana, only 3 cases, 0.3 per cent. 
of whites and 0.2 per cent. of negroes; Necator americanus, 10.7 per cent. of 
whites and 3.3 per cent. of negroes. The question may be raised as to whether 
the thicker skin and the odor of the feet may serve as a protection in the case 


202 THE JOURNAL OF “PARASITOLOGY 


of the negro, or whether there is a partial resistance developed in the native 
home of the parasite and of the negro in Africa. 

Dr. Ransom presented a note reporting a case of Paragonimus westermanii 
or P. kellicotti in a cat. The diagnosis is based upon eggs found in the bronchial 
mucus and muscles by Dr. W. H. Schultz of Morgantown, West Virginia, speci- 
mens of which were sent to the Bureau of Animal Industry for identification. 
Cases of Paragonimus are occasionally found in hogs killed at certain meat 
inspection stations, particularly at Cincinnati, Ohio, but none of these cases has 
been traced to the point of origin. Hence the present case is of special interest, 
as it indicates a probable center of infection, in the neighborhood of which other 
cases may be expected to occur. 

Mr. Crawley presented a note on the geometrical ratio of multiplication in 
the increase of protozoa in infestation, with an apparent exception in the case 
of sarcosporidia. 

The presence of Sarcocystis muris in a mouse from which the skin has been 
removed, is readily detected. The cysts, owing to the presence of refractive 
granules, look like white threads running lengthwise in the muscles. When 
scarce, however, they may be confused with the connective tissue fibers or even 
overlooked altogether, and such cases can only be positively diagnosed by the 
use of the microscope. 

In the case of thirteen mice, which either died or were killed at known 
periods after inoculation, five were macroscopically negative, but the microscope 
showed them to be positive. The periods elapsing between inoculation and 
death were, respectively, 75, 75, 83, 211 and 273 days. 

The remaining eight mice were all macroscopically positive, and the charac- 
ter of the infections was classified as slight, moderate and severe, the latter 
being those cases wherein the flesh of the mouse is so overloaded with cysts that, 
considered as a whole, it is white and not red. The slight infections numbered 
two, with periods of 100 and 205 days. The moderate infections numbered four, 
with periods of 158, 175, 225 and 233 days. The two severe infections had 
periods of 216 and 233 days. 

The indications from these data are that the time during which the infection 
has lasted and the intensity it finally assumes bear no relation to each other. 
Thus, two of the cases which required the microscope for their demonstration 
had periods of 211 and 273 days, whereas the periods for the two severe cases 
were only 216 and 233 days. 

Hence the inference is that the number of cysts which finally appear in the 
muscles is directly related to the number of spores originally ingested. If so, 
this would constitute a noteworthy exception to the general rule for infections 
of parasitic protozoa to the effect that the severity an infection ultimately 
attains bears no relation to the number of individuals originally inoculated. 
This, of course, is due to the fact that, in general, the parasites increase in geo- 
metrical ratio, and continue to do so until the host succumbs or establishes a 
successful resistance. This latter contingency cannot be invoked in the present 
case, since Sarcocystis muris is fatal to mice. 

The data above given were obtained only incidentally in the course of a study 
of the life history of S. muris, and hence cannot be regarded as at all conclusive. 

Maurice C. HAL, Secretary. 


APPENDIX 


For the convenience or information of investigators, attention is called to the 
place of publication of the earlier proceedings of the Helminthological Society 
of Washington. Previous to publication in THE JOURNAL OF PARASITOLOGY, 
all the Proceedings were published in Science, as follows: 


Vol. 33, new series, No. 840, pp. 197-198, Feb. 3, 1911 (first and second 
meetings). 


Vol. 33, new series, No. 848, pp. 510-512, March 31, 1911 (third meeting). 


HELMINTHOLOGICAL SOCIETY OF WASHINGTON 203 


Vol. 33, new series, No. 850, pp. 590-592, April 14, 1911 (fourth meeting). 

Vol. 33, new series, No. 860, pp. 974-976, June 23, 1911 (fifth and sixth 
meetings ). 

Vol. 35, new series, No. 901, pp. 553-556, April 5, 1912 (seventh, eighth and 
ninth meetings). 

Vol. 35, new series, No. 903, pp. 635-636, April 19, 1912 (tenth meeting). 

Vol. 35, new series, No. 906, p. 756, May 10, 1912 (eleventh meeting). 

Vol. 37, new series, No. 941, p. 78, Jan. 10, 1913 (twelfth meeting). 

Vol. 37, new series, No. 944, pp. 197-198, Jan. 31, 1913 (thirteenth meeting). 

Vol. 37, new series, No. 952, pp. 498-499, March 28, 1913 fourteenth meeting). 

Vol. 37, new series, No. 954, pp. 577-578, April 11, 1913 (fifteenth meeting). 


BOOK REVIEWS 


THE DIAGNOSIS AND TREATMENT OF TropicaL Diseases. E. R. Stitt. 421 pp. 
86 illustrations. P. Blakiston’s Son & Co., Philadelphia. 

This work is more than ordinarily interesting to the parasitologist because of 
the position and work of the author, who has also written a good text on animal 
parasitology. The present book emphasizes the clinical aspect of the subject, 
and is intended as a companion volume to the earlier work. Fortunately, the 
idea is not carried out rigorously, for in each case a brief statement concerning 
laboratory diagnosis concludes the discussion of a particular disease. 

The classification of diseases which is distinctly modern brings together those 
due to protozoa and those due to helminthes in two of the chief subdivisions of 
the text. The discussions of these organisms, while necessarily brief, are in the 
main very good, as they certainly are complete. The author's style is attractive 
and his knowledge of the literature in this field unusually broad. In a few 
cases poor figures were selected, but in general they are adequate, though 
variable in effect. 


Fries IN RELATION TO DisEASE: Bloodsucking Flies. Edward Hindle. Cambridge 

University Press. 1914. 8°. 398 pp. 88 figures. 

This volume belongs to the Cambridge Public Health Series and is a com- 
panion volume to one on Non-Bloodsucking Flies. The introductory chapters 
discuss clearly and briefly the general problem of the indirect and direct 
transmission of pathogenic agents, the relation of the definitive and intermediate 
hosts and their parasites, the external and internal anatomy of adult flies, the 
anatomy and development of the immature stages and the classification of flies. 

The general subject is introduced by a tabulation giving a complete list of 
the families containing bloodsucking species, a list of the species known to trans- 
mit an infective agent, the disease transmitted, their geographical distribution 
and the authorities responsible for the record. This table is supplemented 
by another giving the known species of Anophelinae, their present generic loca- 
tion, notes on their habits and connection with malaria. The text contains 
analytical tables for the identification of the families of Nematocera, Brachycera 
and Calyptratae, for the identification of the genera and species of Psychodidae 
and Culicidae, the genera of Muscidae and the species of Glossina. 

The families are arranged in their systematic sequence, and under each there 
is given a detailed discussion with figures of the external and internal anatomy 
of the adults and immature stages, the habits and development of the immature 
stages, their enemies and means of combating them. Following the systematic 
discussion in each case, there is a careful consideration of what is known regard- 
ing the various diseases transmitted by bloodsucking flies and their causal 
organisms, the morphology, life cycle and development, and in many cases maps 
showing the geographical distribution of the insect carrying the parasite. The 
chapters dealing with malaria, yellow fever, dengue, filariasis and trypanoso- 
miasis are especially full and to be commended. It is a well-arranged, clearly 
written, readable volume. 


HANpgBook oF MepicAL ENtomotocy. By William A. Riley, Ph.D., Professor of 
Insect Morphology and Parasitology, Cornell University; and O. A. 
Johannsen, Ph.D., Professor of Biology, Cornell University. Ithaca, N. Y.: 
The Comstock Publishing Co., 1915. 348 pp. 

The appearance of this splendid volume will do much toward placing this 
country in a leading position in medical entomology, such as it now occupies 
in other branches of applied entomology. Moreover, the wide distribution which 
this work is certain to receive doubtless will cause an awakening of interest in 


BOOK REVIEWS 205 


the subject and a recruiting of the workers from the ranks of the entomolo- 
gists and medical men which should do much to further our altogether too 
meager knowledge of the relationship of insects and acarines to disease. 

While the authors do not profess to have had extended experience in research 
along these lines, they show a broad acquaintance with the literature of the 
subject from ancient to modern times, and have exhibited marked skill in 
assembling in concise form the principal facts recorded by an army of investi- 
gators in all parts of the world. 

The subject is treated by grouping the matter according to the way Arthro- 
pods are connected with the various maladies. It was expressly not the authors’ 
desire to treat all of the diseases known to be carried by Arthropods, but to 
endeavor to cite a number of the best illustrations of the different methods by 
which insects act as disease vectors. This has resulted in the omission of some 
well-established cases in which insects play an important role. It is regrettable 
that more information might not have been given regarding the life history and 
habits of some of the Arthropods, as the possession of such knowledge lends 
much to the solution of the problems of insect control, and often suggests the 
potentialities of an insect or a group of insects in disease transmission. 

The style of the authors is interesting, the print good and the illustrations, 
though largely borrowed, are well chosen and very satisfactorily reproduced. 
The compactness of the volume is also a desirable factor. Certainly the work 
will be of wide usefulness. 


Some Minute ANIMAL ParRASITES OR UNSEEN Fors IN THE ANIMAL WORLD. 
H. B. Fantham and Annie Porter. 319 pp., 56 figures. Methuen & Co., Ltd., 
London. 

The authors state that the aim of the book is to give a readable account, popu- 
lar but accurate, of the life histories of some microscopic protozoal organisms 
that produce disease in higher animals, including man. Emphasis is laid on 
topics of economic importance: sleeping sickness, malaria, dysentery and kala- 
azar in man; tstse-fly disease and redwater in cattle; coccidiosis in game and 
domestic birds; certain fish maladies and insect diseases. The relations of para- 
sites to their environment and to commerce are discussed’ in certain chapters, so 
that the needs of students, sportsmen, breeders are met, as well as those of 
general readers. The task is great and the book modest in size. 

After reading it one lays the book aside with mingled feelings of satisfac- 
tion and regret; satisfaction that the authors have succeeded so well and regret 
that more topics are not handled in similar fashion by those who can speak 
with such authority on the subject treated. Especially in this country is there a 
dearth of books on the advances of science in definite directions that can be 
commended to the general reader unfamiliar with the intricate terminology and 
technicalities of the investigator. Usually either the men who know cannot 
write, or those who write do not know. But this volume is both accurate and 
attractive. 

The senior author has done much fine work on difficult problems involving 
the Sporozoa, and the junior author has also demonstrated her grasp on para- 
sitic protozoa, so that it is not surprising to find a masterful treatment of the 
topic. The work is marvelously complete when one considers the narrow limits 
of space and the complexity and unfamiliarity of the subject. Unlike most 
elementary treatises, this one is generous in the citation of authorities, and so 
far as noted accurate, a virtue conspicuous by its absence in most such books, 
One feels like applauding this virtue, because it is usually confined to more 
technical publications, and yet it is the general scientific reader who has most 
need to hear the names of those who have laid the foundations of the science. 

Furthermore, this book reads well. Scientific terms are used sparingly, and 
when employed are carefully defined. The authors adopted the plan of discuss- 
ing these organisms from the biologic rather than from the taxonomic stand- 
point, and while they use with accuracy the scientific names of the various 


206 THE JOURNAL OF PARASITOLOGY 


pathogenic protozoa and group them together in a fashion that accords with 
proper systematic conceptions, they avoid the introduction of a mass of classifi- 
catory subdivisions which impart such a ponderous impressiveness to many 
texts. The descriptions of the various life histories, which are of such signifi- 
cance in the transmission and prevention of disease, are both vivid and accurate. 
Even recently elucidated phenomena, such as granule-shedding in spirochetes 
and in the organism of syphilis, are explained clearly so that the work may be 
commended for its completeness as well. 

The illustrations are rather scanty, perhaps because of the limited space, and 
some of them are distinctly wooden in being schematic to an unnecessary degree. 
Or if that feature was retained by choice, then they might have been reduced 
considerably to make space for other figures. , Thus it was surely not necessary 
to use a full page for a diagram of the bee’s alimentary canal; every detail rep- 
resented would have been equally clear in a cut half the size or even smaller. 
For an audience of the type to which the book appeals, an abundance of illus- 
trations is indispensable, as the descriptions alone give a vague idea of the 
appearance of such unfamiliar things. This is the one weak feature in a very 
successful work; yet despite it the book should be recommended widely and 
strongly to all seeking knowledge of this new and fascinating field of recent 
discoveries concerning: life and disease. 


NOTES 


Tue Preliminary Report of the Institute of Tropical Medicine and Hygiene 
of Porto Rico summarizes the work done during an expedition to the interior. 
In sixty working days over 10,000 persons were thoroughly examined. The 
report contains an interesting table of Diseases due to Animal Parasites. 


DISEASES DUE TO ANIMAL PARASITES 


Primary Secondary Total 

Umncinariasis (Necator armericanus))..........00...0..00-0e= 307 680 987 
Ascariasis -(Ascaris lumbricoides))......................--- 44 555 599 
‘Rrichuriasis, CUrichuris, tricbitina)) errs a er= is fiero eimiie cl ehalies =) > 1 152 153 
Strongyloidosis (Strongyloides stercoralis)...........--...- eae 10 10 
Balantidic Dysentery (Balantidium coli).................-. 1 1 @ 
Oxyuriasis (OxyirsS) venmiewlanis) ie ere iervetel seein iterates! eter sNeletelle 2 1 3 
Amepiasiss (Gatamebal HiStoly tical. sereis a ci-i ict sah ele )eilsiolial-telclisielets 3 1 4 
Schistosomiasis (Schistosoma mansoni)................+++. 206 22 228 
Malaria OP lasmodivind “vivax... 6ci2 stereo sts) + ciel sisisl ioieietels/eislle 2 Se 2 
Majlanan (laverania analariae) ics sar) slclelele sie =tesisto ile beteteire se 6 6 
Pilaniasiss (doubt) CPilaria bancrohty) ik ..)- ists clone 4 1 5 
INSUIGIBEIK,. yom aoe agE Dou ONO stop Aconmanmons SoAcdoboodacs HAC 6 1 1 
Distomiasis) Gh asciOlay HEPALICA) iaravelevalats <tevern ro Uarovaratcts) cteeetionsiere wea 1 1 
Flagellate diarrhea, species undetermined...............+-- 2 Pteic 2 
578 1,425 2,003 

TPotaldisenses; treatedeya. esuncislessericvere woveaciceyo eieymieteneusvareteneterets 1,923 1,991 3,914 


In the comment it is stated that in 1904 70 per cent. of cases at Utuado were 
found infected with hookworm and 90 to 98 per cent. at Mayaguez. The intensity 
of the infection and of the disease was much less this year. In ten years over 
300,000 persons have been treated on government initiative and 200,000 on their 
own responsibility. Even yet 51 per cent. of all cases examined were found to 
be infected with hookworm. 

Infection with roundworms was heavy beyond comprehension, but with 
comparatively few serious symptoms. Schistosomiasis was found mostly in per- 
sons living near the Vivi and Grand rivers and bathing in them. Only two foci 
of malaria were found, limited in area. The workers were entirely unable to 
find microfilaria in any case. The tropical form of ameba was not common at 
the time of the work. 


NOTES. 207 


Tue International Commission on Zoological Nomenclature has finally reached 
a decision with regard to the spelling of the scientific name of the European 
hookworm. This will be welcomed by all. The confusion of some twenty 
variants which have burdened our recent literature, and the appeals of partisans 
for their particular type have grown unendurable. Even those who do not like 
the form chosen must welcome a decision finally. Yet despite some murmurs 
from outside sources that this form, Ancylostoma, was not well chosen,’ and 
granted that the German will always spell the name with a k and others will 
follow because it sounds right to them, one may confidently predict the early 
and general introduction of the new form. It is simple, philologically defensible, 
and if pronounced after the Latin method, just what every one has used here 
and abroad. Undoubtedly, the most important end is to secure uniformity and 
for that some system is demanded. : 

It is equally clear that the form of ankylostoma will persist as a common 
name alongside of the technical form, just as the common name trichina is in 
constant use, though the correct scientific designation is Trichinella, or as one 
speaks of crustacea and a host of other groups which are correctly written in 
the scientific form with a capital letter. The process of popularizing technical 
terms has already gone a long ways in medicine, botany, zoology and other fields 
of science, and with increasing knowledge and interest will go much further 
in the near future. We shall come to look to authoritative bodies in each field 
to determine spelling and usage for us, and will adopt the decision of such com- 
missions without discussion when we have put into practice our theory that 
such bodies know better what should be done than the educated outsider can 
possibly determine by any investigation. 


In the death of von Prowazek on February 17, last, parasitology has suffered 
an irreparable loss. Like his distinguished predecessor, Schaudinn, and our 
own Ricketts, he sacrificed his life at an early age in the pursuit of his investi- 
gations undertaken in the interest of science and humanity. When typhus broke 
out in a German prison camp he entered upon a study of the disease and fell a 
victim to it. As a brilliant thinker, a keen investigator and a voluminous writer 
he has already exercised a dominant influence on the development of this field 
of science. By virtue of work which has no limits in country or time and serves 
all nations for all ages, he was a benefactor of the whole world and will be 
honored as such. 


1. Editorial, Jour. Am. Med. Assn., March 27, 1915, p. 1081. 


INDEX TO VOLUME I 


PAGE 
meanthocephala in North American Amphibia. .......0......2.0.cecee eee: 175 
Ackert, James E.: Experiments on Cysticerci of Taenia pisiformis and of 
URL VENE AIS OPEN GaN Cre AUS tyme ar ted te Oe ere Pe alo a Rona, 8 ash Ol ples wack nck, oneresd ig wee 151 
Action of Arsenical Dips in Preventing Tick Infestation, The.............. 48 
PNET CEIN CLI caeMRe rT eter tare Pevelcictotche eeteteie othe oie aieie ls che siveeciohasdlocue vues cere id 9) 
Eppeal to, American tlelminthologists, Amis. fc.0s.6. 002. 6. chee cecccseeas 104 
mcthropods, Kallinge Small with the Legs Extended. :...2.... 00.0... 0200.. 105 
miscaris lumbricoides, Observations on the Eggs of... 0035... c.cceeeecseue 31 
Barker, F. D.: Parasites of the American Muskrat (Fiber zibethicus)..... 184 
Bancettiqe Vines See! Smith, Ame cand spanretivWl. Ghia. 65).4.65. 0. nen. +: 159 
HOO Km RN CULCW SipeTen Somes is tne ce hen EEA Aa cae A aia eS ADND Asie SOME Seals 156, 204 
Burge, W. E., and Burge, E. L.: The Protection of Parasites in the Diges- 
tive Tract against the Action of Digestive Enzymes ............... 179 
Cobb, N. A.: Rhabditin: Contribution to a Science of Nematology........ 40 
Cooley, R. A.: Killing Small Arthropods with the Legs Extended......... 105 
Cort, William Walter: Gordius Larvae Parasitic in a Trematode.......... 198 
Larval Trematodes from North American Fresh-Water Snails.... 65 
Coutant, Albert F.: The Habits, Life History and Structure of a Blood- 
suckine \Muscid Larva (Protocalliphora asurea)..:. 6.0 .00..deccsevess 135 
Craig, Charles F.: New Varieties and Species of Malaria Plasmodia....... 85 
Cysticercus bovis, The Destruction of the Vitality of, by Freezing.......... 5 
Cysticerci of Carnivore Tapeworms, Experimental Ingestion by Man of.... 42 
Cysticerci of Taenia pisiformis and of Taenia serialis Gervais. Experi- 
FACETS OEM. ath ecole ee COERCED OO PE Ces CI hol Eames EE oe 151 
Danlinese Seb. Sarcosponidia, Encountered im Panama. .c.sssesc.s20eeenne 115 
Destruction of the Vitality of Cysticercus bovis by Freezing, The........... 5 
Dire NOt-ssDheory of Insect Causation of Disease... ..0..4..c080.4.. 404 ee o7, 
Endameba gingivalis Gros, The Parasite of Oral Endamebiasis............ 159 
Enzymes, The Protection of Parasites in the Digestive Tract against the 
NGCHO MMO Peel) SeEStivies TS aaiescti. Uni rieS a Ea ert ae Awe Bn ee 179 
Eorhynchus: A Proposed New Name for Neorhynchus Hamann Preoccu- 
Fes ME Peer ft ih cD oem a. © avah ters ct AMAL SEE ele dict a drcaets Bike oe 50 
Euproctis chrysorrhoea Linn., The Poison Glands of the Larva of the . 
IB Rani Tiale IRENA NY ICo\8 By sparc eas Seimei c diccicine Ee Scie RE ee Coe oe ee Ree 95 
Experimental Ingestion by Man of Cysticerci of Carnivore Tapeworms.... 42 
Experiments on Cysticerci of Taenia pisiformis and of Taenia serialis 
(GETANIG, “len cio oa ROR bead DIAS Bie, Gc Oer ar ae ORE aoe era eer eee: anne 151 
Fiber zibethicus, Parasites from the American Muskrat.................... 
Foster, Winthrop D.: Observations on the Eggs of Ascaris Lumbricoides 31 
Foster, Winthrop D.: Peculiar Morphologic Development of an Egg of the 
Genus Tropidocerca and Its Probable Significance, A.................. 45 
Fracker, Stanley B.: Variation in Oxyurias: Its Bearing on the Value of 
gi IN[ieiaayrocle [armani 3’ See o ee cketad moo Oe ag Soe nae eo chon ec eetOn rs: 22 
Pridmionicduvaeakarasitic ina > Prematode yo tide sc sii 05. ccuesintes cic oie oh 198 
Graybill, H. W.: The Action of Arsenical Dips in Preventing Tick Infection 48 
Hall, Maurice C.: Experimental Ingestion by Man of Cysticerci of Carni- 
ORS. LATENT es & Aine AM Eee iS EECIaS oO ere Pee Rise rc 42 
Helminthological Society of Washington, Proceedings......... 52, 106, 154, 200 
Habits, Life History, and Structure of a Blood-Sucking Muscid Larva 
CZ OLOGQIP MOKA GUSULE GI) ache estes cla cle aislert eo avsl evolve acho oe ortleaiahe cee atele 135 
insecta@ansationvo Wisease,; Dr. Knotts Dheory Of... ...-.2.5-5..eesse eee 37 
Jennings, Allen H.: Summary of Two Years’ Study of Insects in Relation 
10 


CMe a CML ERL clmrrmeb er ee fe ceare tiie. ss Ae nt cota ier eta She's cueyern as sots, Mol muse eters OME MEN ate! 3 alist 


Yy 


INDEX” TO” VOEUME “TI 


PAGE 
Kelloge,’ Vernon E.: ‘Spider*Poisen” . so. 6... 2. cacao eee 107 
Kephart, Cornelia F.: The Poison Glands of the Larva of the Brown-Tail 
Moth (Buproctis chrysorrhea Winn.) \.\., .: .%,..ccsk wns ale ee 95 
Killing Small Arthropods with the Legs Extended.... 2... .22seeeeee eee 105 
Larval Trematodes from North American Fresh-Water Snails............ 65 
Pocotrema lingua (Creplin): ........ 0. 0 s6as cess Salen tlak ons Oo 128 
Malaria Plasmodia, New Varieties and Species of...........2:0s005s000csss 85 
Mrazek, Al.: An Appeal to American Helminthologists.................-. 104 
Muskrat, (Fiber zibethicus) Parasites from the American..............<. 184 
Nematode Formula, Variation in Oxyurias: Its Bearing on the Value of a.. 22 
Nematology, Rhabditin: Contribution to a-Science of: ..3..2-.25 «seeeeeee 40 
Neorhynchus Hamann Preoccupied. Eorhynchus: A Proposed New Name 
EOD ge ahsies eed Ruciomeshs fe erebalseis Sava ae abide &.b Gils FORO Oe MLO 50 
News Varieties and Species of, Malaria Plasmodia...4..4. 05) seee eons 85 
North American Amphibia, Acanthocephala im: .:..0:/.029.25 ace eee 175 
LCOS. <A ag SE OE REE Rn SSR ERE EO PET RIE 54, 106, 156, 206 
Observations on the Eggs of Ascaris lumbricoides.........0. 0000 eececeeees 31 
Oral Endamebiasis (Endameba gingivalis Gros) The Parasite of........... 159 
©facariasis; in the Bighorine.<. 9.0 céSieitsatgerce snes obmaae eles Se eee 123 
Oxwyurias, Variation in: Its Bearing on the Value of a Nematode Formula. 22 
Parasite of Oral Endamebiasis (Endameba gingivalis Gros)...........+-- 159 
Parasites of the American Muskrat (Fiber zibethicus)....:.2:.0.9eee eee 184 
Peculiar Morphologic Development of an Egg of the Genus Tr opidocer ca 
and. Its. Probable. Significance. isc. i... <'0..c20clse Siew oo 45 
Pellagra, Summary of Two Years’ Study of Insects in Relation to........ 10 
Poison Glands of the Larva of the Brown-Tail Moth (Euproctis chrysorrhea 
PATI) re ctaesoccis MOSARAE Dice gle Sm Saker aes ae ye a Re heh 95 
Protection of Parasites in the Digestive Tract Against the Action of the 
Digestive: EM Zy tits x ciccyc chovsva ‘a, obs whe abe srs pots sc¥.e1avosacafarcitiewseve cae hee 179 
Protocalliphora azurea, The Habits, Life History and Structure of a Blood- 
Sucking Muscid Warva)...:.6.¢.00hs.00c8 ane tock ose ane eee 135 
Ransom, B. H.: The Destruction of the Vitality of Cysticercus bovis by 
BPCOZING cir sd dui! Eaee Ra one doblejtiew oa seine oa Mie cheese 5 
Rhabditin: Contribution to a Science of Nematology.............-.-+-seee- 40 
Riley, William A.: Dr. Knott’s Theory of Insect Causation of Disease...... oY 
Sarcosporidia ‘Encountered im Panama... ........00 sds)»: oe ee 115 
Smith, A. J., and Barrett, M. T.: The Parasite of Oral Endamebiasis, 
(Endameba® gingivalis Gros) 2. o's cas sens oo debeke eee ote 159 
SPIG|SH TROLS OM so rsicrstocsrencvecsense:a:ciaserous.oleversfovsvaverarsesceVa ss bs ERO aR eRe eee 107 
Summary of Two Years’ Study of Insects in Relation to Pellagra.......... 10 
Taenia pisiformis and of Taenia serialis, Experiments on) Cysticerci"ote. eee 151 
Tick Infestation, The Action of Arsenical pes in), Preventing --eee ere 48 
Aekys PATALY SiS he co biecasgites:dusrere asides og 4 orm saline Meee Oe nL ee ae 55 
Locotrema ‘lingua. (Creplin) 01.4.2... 035s dscns culm eloeies seen See eee 128 
Todd, Johnel:: Tick *Paralysis. £3... csi. os cba neeeioinet ban eee 55 
Trematode, ‘Gordius. Larvae Parasitic in a..2..../. 0.9.0... eee eee 198 
Trematodes, Larval, from North American Fresh-Water Snails............ 65 
Tropidocera, A Peculiar Morphologic Development of an Egg of the Genus, 
and, Its Probable: Significance’, \..<. <. s/o ste oe ieee ie te eee ee 45 
Van Cleave, H. J.: Acanthocephala in North American Amphibia........ 175 


Eorhynchus: A Proposed New Name for Neorhynchus Hamann Preoccupied 50 
Variation in Oxyurias: Its Bearing on the Value of a Nematode Formula.. 22 
Ward, Henry B.:.Otacariasis in the Bighorn. 22.21.23. 25.25. 5 eee 123 


The Numbers of Volume I of the JourNAL oF PARASITOLOGY were mailed as 
follows: 
No. 1. Sept. 19, 1914. No. 3. March 22, 1915. 
No. 2. Dec. 18, 1914. No. 4. July 16, 1915. 


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