Concerning the parasites and parasitic diseases of this miscellaneous
assemblage of large mammals, I shall first speak of those of the
proboscideans (Elephantidæ). Except by myself, they have been but
little studied, and I am yet waiting for an opportunity to give further
time to their consideration. When Diesing published his ‘Systema’ only
two helminths were referred to the Indian elephant, namely, _Ascaris
lonchoptera_ and an undescribed fluke supposed to be a distome. The
whole subject requires revision, but I think the following species must,
for the present at least, be allowed recognition:--_Fasciola Jacksoni_
(mihi), _Amphistoma Hawkesii_ (mihi), _Ascaris lonchoptera_ (Diesing),
_Sclerostoma Spinuliferum_ (Baird), and _Dochmius Sangeri_ (mihi).
Either the _Ascaris_ or the _Sclerostoma_ is probably identical with
Rudolphi’s _Strongylus elephantis_.
At the Norwich Meeting of the British Association, in 1868, I exhibited
two flukes received from J. S. Thacker, V.S., of the Madras Army. They
were handed to me by the late Dr Baird, and were labelled “Distoma
taken from liver of elephant and forwarded for classification.” I
stated at the time that these entozoa were identical with certain
flukes previously obtained from the duodenum and biliary ducts of an
Indian elephant, and which, though carefully preserved in the Boston
Museum, U.S., had never been properly described. They were only briefly
noticed by Dr Jackson in his ‘Descriptive Catalogue’ of the Museum. In
the summer of 1868 fifteen specimens of fluke, removed from Burmese
elephants, had been forwarded to and received by Professor Huxley
from Rangoon, accompanied by a statement to the effect that they were
the cause of an extensive and fatal disease in Burmah. Through the
kindness of Prof. Huxley I was allowed to make use of his specimens
for the purpose of comparison and identification, and thus it became
evident that our specimens were of the same species. It was also evident
that the species could be none other than that represented by the
Boston specimens. Further examination having made it clear that the
organisation of these flukes departed from the ordinary distome type, I
named the parasite _Fasciola Jacksoni_, at the same time offering the
following description (‘Entozoa,’ Supp., 1869, p. 80):--“Body armed
throughout with minute spines, orbicular, usually folded at either end
towards the ventral aspect, thus presenting a concavo-convex form; oral
sucker terminal, with reproductive papillæ about midway between it and
the ventral acetabulum; intromittent organ 1/4″ in length; digestive
apparatus with two main zigzag-shaped canals, giving off alternating
branches at the angles thus formed, the ultimate cæcal ramifications
occupying the whole extent of the body; length, when unrolled, from
1/2″ to 5/8″, breadth 1/3″ to 1/2″.” Now, if reference be made to the
appendix of the late C. M. Diesing’s ‘Systema Helminthum,’ it will be
found that Jackson’s statement had not escaped that helminthologist’s
notice, though, not having seen any specimens, he was not unnaturally
led to place the species amongst the distomes proper. In Diesing’s
subsequently published ‘Revision der Myzelminthen,’ the species
is formally characterised as the _Distomum elephantis_ of Jackson
(‘Sitzungsberichte d. Math.-nat. Cl. d. k. Akad. d. Wissenchaften,’ Bd.
xxxii, 1858). In my “Synopsis of the Distomidæ,” which appeared in the
‘Journal of the Linnean Society’ for 1861, I had also placed it amongst
the distomes, not considering it to be a doubtful form (‘Proceed.
Linn. Soc.,’ “Zoology,” vol. v, p. 9). These references exhausted the
literature of the subject up to the time of the issue of my ‘Manual’
in 1873, where this fluke is again briefly noticed (p. 13). Several
of Prof. Huxley’s specimens have been added to the entozoological
department of the Hunterian Museum. It is clear that all these notices
and descriptions point to the same parasite. The worm has since been
more carefully described by Dr R. H. Fitz, from a series of dissections
and preparations made by Dr H. P. Quincy, and deposited in the Warren
Museum, Boston, U.S.
About the middle of June, 1875, I received a letter from General Hawkes,
of the Madras Staff Corps, dated Secunderabad, May 12th, 1875, and in
reference to the subject before us he writes as follows:--“My attention
has been recently directed to a very unusual mortality of elephants
at this station. Out of twenty-eight elephants under my charge, no
less than twelve have died within the last sixteen months, whereas the
average annual mortality has been hitherto only two per annum out of
thirty-eight in our establishment. In every case of death there appeared
to exist serious organic disease quite sufficient to account for such
death, but as the mortality increased I had a post-mortem examination
made in each case; and although here also organic disease sufficient
to account for death was present in each case, yet in every one of
these elephants we found the liver-fluke in greater or less abundance.”
General Hawkes adds:--“Meanwhile I have sent you a small box containing
three bottles, one containing the liver-fluke (_Fasciola Jacksoni_)
referred to in your work on the parasites of domesticated animals. It
seems possible that the other two species of parasites may not have
been brought to your notice. Both of these, namely, the “masuri” and
the “soorti,” are very common in elephants. They are both found in the
intestines only. The “masuri,” when present in any quantity, cause
considerable disturbance, and the animal instinctively resorts to the
_eating of earth_, which it consumes in large quantities until the
bowels are acted on and the worm expelled. The soorti is more common
than masuri, and does not seem to inconvenience the animal very much.
When expelled from the animal the soorti is a round white worm, like
most of the threadworms; the masuri, on the other hand, is of a delicate
flesh color.” Shortly after the receipt of this letter I obtained the
entozoa in a good state of preservation. Accordingly I wrote to General
Hawkes, stating that the flukes were clearly referable to _Fasciola
Jacksoni_; that the parasites to which the natives of Hindostan apply
the term “soorti” were evidently examples of _Ascaris lonchoptera_
(Diesing), previously called strongyles by Rudolphi; and that the
worms which he called “masuri” were trematodes new to science. I named
the species _Amphistoma Hawkesii_, in honor of the donor. The bottle
contained as many as forty-nine specimens. I may here remark that I
have made inquiries of the keepers of the elephants at the Zoological
Gardens as to whether they have ever seen entozoa that were passed by
the animals under their care. They replied in the negative, the keeper
of the African elephants (Scott) having made frequent inspection of the
fæces. I was the more anxious to secure information on this point since,
during my frequent visits to the menagerie, I had observed that the
African elephants were in the habit of swallowing large quantities of
mud and dirt from small hollows in the ground near the great water-tanks
in which they bathe. Prof. Garrod (who had dissected three elephants)
also assures me that there has been no trace of an entozoon in any of
the Indian elephants examined by him. In one dissected at Edinburgh
the same negative result was obtained. From the facts at present in
my possession, I conclude that the habit of earth-eating, displayed
alike by Indian and African elephants (and, as stated in my account of
the equine parasites, shared by horses), is not necessarily due to the
presence of parasites. I apprehend rather, that it is resorted to by
these animals under any circumstances of intestinal irritation, whether
created by entozoa or other foreign agents. The notion of the elephant’s
intelligent self-cure by eating earth is a very old fable. Captain
Forsyth, as quoted by Mr Fleming, alludes to it in his ‘Highlands of
Central India,’ and I find the same ideas recorded by Williamson and
Howitt. Forsyth says:--“Elephants are very liable to intestinal worms.
They generally cure themselves by swallowing from ten to twenty pounds
of earth.” Captain Williamson says:--“They are much troubled with
worms, for the cure of which the elephant eats earth. If the dung be
inspected there will be seen an amazing number of moving objects, which
much resemble pieces of chewed sugar-cane.” Some excellent practical
remarks are added, testifying to the value of the native remedy called
_Kallah-nimok_, or _bit-noben_, which is a saline purgative. In Lieut.
Ouchterlony’s essay (quoted below) no allusion is made to the subject of
worms.
General Hawkes afterwards supplied me with further information. In a
letter from Secunderabad, dated July 30th, 1875, he says:--“As regards
the liver-fluke (_F. Jacksoni_), it appears from your treatise to
have been first observed in 1847. The only other published notice
that I have been able to find of it is contained in a letter to a
newspaper, dated ‘Rangoon, 16th July, 1867,’ and is signed ‘R. B.’
In this letter the unusual mortality of seven elephants in about
fifteen days is attributed to the presence of this liver-fluke, the
two other parasites (_Amphistoma_ and _Ascaris lonchoptera_) being
also present in the intestines.” “Now (continues General Hawkes), in
every case at which I was present _flukes were found in greater or
less numbers_ in the gall-ducts of the liver, and the _Amphistoma_ was
also as constantly present in the intestines, the soorti (_Ascaris
lonchoptera_), contrary to the general experience of the elephant
attendants, being less frequently met with, though from its color and
slender shape it is not so easily detected among the huge mass of
fæces as the larger _Amphistoma_.” Speaking of the amphistoma General
Hawkes says:--“This internal parasite is well known to all who
possess elephants. It is alluded to by Dr Gilchrist in his treatise on
the ‘Diseases of Elephants,’ first published in 1841, but he merely
mentioned it under its local name, _masuri_, and made no attempt
either to describe it scientifically or to ascertain its place in the
natural system. As far as my experience goes it is only found in the
intestines. These parasites appear to be very generally present in the
elephant. When their numbers are few the ‘host’ is probably not much
inconvenienced, but when present in any great quantity they undoubtedly
cause much irritation. When this is felt, the animal, as before
remarked, instinctively resorts to a simple and effectual remedy. He
eats a quantity of earth, which purges him thoroughly and expels the
amphistoma. The mahawats are of opinion that whilst the elephant is
eating earth to relieve himself of the pests the daily allowance of rice
should be scrupulously withheld; and they say that if the rice, which
is given uncooked, is eaten by the animal under these circumstances,
excessive purgation is induced, which frequently results in death.
How far this opinion is founded on fact I am unable to say, but the
mahawat’s name for this disease means ‘fasting,’ and bears testimony to
the generally received notion of the necessity of withholding the rice
when the animal is eating earth.”
When describing the parasites of the horse (p. 358), I spoke of
Collins’ amphistome from that animal, but in the letter addressed to
me from Simla, 22nd March, 1875, Mr. Collins made no allusion to the
earth-eating habit. He wrote:--“I forward you by this mail parasites
found in the colon of a horse that died, a subject of fever peculiar to
this country. There were _about a thousand_ of the parasites, and nearly
the whole of them were situated close to the cæcum, and were loose in
the gut. Not having seen parasites at all similar to these, I have
forwarded them for identification. They were of a brick-red color when
first obtained.” These explicit statements by Mr Collins are interesting
from many points of view. One has only to place his specimens side
by side with those from the elephant in order to satisfy one’s self
that the two forms are distinct. For the reasons already stated I
provisionally called the worm _Amphistoma Collinsii_. It is probable
that other veterinary surgeons have encountered this entozoon in India;
but, unless they can point to some published account of the fact, Mr
Collins is entitled to be considered as its discoverer. Doubtless many
other European residents in India, Ceylon, and Burmah, must, like Dr
Gilchrist, be well acquainted with the _masuri_ as such, though unaware
of their zoological position.
In a record of the post-mortem examination of one of the victims of the
Secunderabad epizoöty, the veterinary surgeon said:--“No doubt disease
of the lungs and subacute inflammation of the bowels were the immediate
cause of death, but the large number of flukes in the liver and the
intestinal parasites (_i. e._ the amphistomes) account in a great
measure for some of the symptoms shown, and these symptoms accord in
many respects with those shown in elephants that died in Burmah during
the epizoöty (rot) in 1867, as recorded by R. B., notably, refusal of
food, standing with mouth open, restlessness, and puffiness about the
head and shoulders. The liver parasite is no doubt the same referred
to by R. B., and is that termed by Dr Cobbold _Fasciola Jacksoni_.” In
reference to a later case the same officer remarks:--“I carried out
the post-mortem examination with special reference to inquiry as to the
probability of the mortality amongst elephants at this station being
of parasitic origin. This was suggested to me by the former case. The
post-mortem appearances differed in every respect. There were flukes in
the liver, but in no great quantity, and the structure of the liver was
sound. Although not assisted by this case in attributing the mortality
to parasitic origin, I am strengthened in my opinion that the death
of the previous elephant was due to disease caused by the presence of
the liver fluke.” This report, by Mr W. S. Adams, is to some extent in
harmony with later information. An epizoötic outbreak amongst elephants
has occurred in England, at Sanger’s Circus, and I had opportunity to
examine one of the dead animals. In my own opinion, and in that of Mr F.
Smith, the veterinary surgeon who attended the animals professionally,
the disease was due to parasites. I obtained large quantities of
_Amphistoma Hawkesii_ from the intestinal canal, and also other worms.
The death of one of the elephants was made the subject of litigation,
when, as might be expected, great diversity of opinion as to the cause
of the fatal issue prevailed.
Mr Smith, an old pupil of mine, regarding the amphistomes and strongyles
as the cause of death, wrote to the effect that “some of the worms were
found between the coats of the intestine, and others on the free surface
of the gut, whilst the excretory ducts of some of the glands were found
blocked with them.” The animal examined by myself on the 24th of August,
1876, yielded numerous examples of _Amphistoma Hawkesii_, _Ascaris
lonchoptera_, and _Dochmius Sangeri_, the last species being so named
by me after the owner of the circus who lost the herd of elephants by
the epizoöty. The male _Dochmii_ measured 5/8 and the females 3/4 of an
inch in length. Here I must reluctantly quit the helminths of elephants,
adding only an expression of surprise that Dr Max Schmidt should have
had so little to say concerning them in his otherwise instructive memoir
on ‘The Diseases of Pachyderms’ (quoted below).
I have but a few words to offer respecting the ectozoa. A species of
mite has been described whose generic position appears doubtful. I
allude to _Homopus elephantis_ of Fürstenberg, or _Symbiotes elephantis_
of Gerlach. According to Mégnin it is a _nymphe adventive_ or _hypope_
of a variety of _Tyroglyphus siro_. This acarus is abundant in old
forage. Another ectozoon is _Hæmatomyzus elephantis_. It differs
from the lice proper in many respects, but, according to Piaget, the
reproductive organs resemble those of _Hæmatopinus_. In ‘Science Gossip’
for June, 1871, Mr H. C. Richter describes “a new form of parasite,”
which is called _Idolocoris elephantis_. The insect, which was one line
in length, was found upon an elephant in Ceylon. According to Walker it
not only constituted the type of a new genus, but of an altogether new
family of the Hemiptera Heteroptera, coming very near to the bed-bugs
(_Acanthidæ_). It is a huge sucking louse. From the discussion which
followed, it seems that the parasite had several times been seen before,
and was none other than E. Piaget’s _Hæmatomyzus elephantis_. Excellent
figures accompany Richter’s and Piaget’s descriptions. Notwithstanding
Piaget’s explanation, I think the specific name, _longirostris_, would
have been a more appropriate appellation.
BIBLIOGRAPHY (No. 51).--(Anonymous), “Diseased Elephants,” see ‘Lancet,’
Sept. 2, 1876; also “Report of the Case at Law (Jamrach _v._ Sanger),”
given in the ‘Veterinarian,’ Dec., 1877, p. 886.--_Cobbold, T. S._,
“Description of a species of Trematode from the Indian Elephant, with
remarks on its Affinities,” ‘Quart. Micros. Journ.,’ Jan., 1869; see
also ‘Entozoa,’ supp., 1869, p. 80.--_Idem_, “On the Destruction of
Elephants by Parasites, with remarks on two new species of Entozoa and
on the so-called Earth-eating habits of Elephants and Horses in India,”
‘Veterinarian,’ Oct., 1875.--_Idem_, “Further Remarks on Parasites
from the Horse and Elephant, with a notice of new Amphistomes from the
Ox,” _ibid._, Nov., 1875.--_Diesing_ (l. c., in text).--_Fitz, R. H._,
“Anatomy of _Fasciola Jacksoni_,” ‘Rep. of Boston Soc. Med. Sci.,’ in
the ‘New York Med. Journ.,’ Nov., 1876.--_Fleming, G._, “The Diseases
of Elephants” (chiefly from Captain Forsyth’s work on the ‘Highlands of
Central India’), ‘Veterinarian,’ March, 1873, p. 181.--_Mégnin_, “Mém.
sur les Hypopes,” in Robin’s ‘Journ. de l’Anat. et de la Physiol.,’
1874 (_H. elephantis_), p. 248.--_Ouchterlony, J. W._, “An Essay on the
Management of the Elephant, and its Treatment in ordinary Diseases,”
‘Rep. of Vet. Med. Assoc.,’ Nov., 1872, and pub. in ‘Veterinarian,’
Jan., 1873, p. 65.--_Piaget, E._, “Description d’un parasite de
l’éléphant,” ‘Tijschrift voor Entomologie,’ 1869, p. 249.--_Richter,
H. C._, “A new form of Parasite (_Idolocoris elephantis_),” ‘Science
Gossip,’ 1871, pp. 131, 185, 211, 278.--_Schmidt, Max_, “Die Krankheiten
der Dickhäuter,” ‘Deutsche Zeitschrift f. Thiermed. und vergleichende
Pathologie,’ f. Nov., 1878, s. 360.--_Williamson, T._, ‘Oriental Field
Sports,’ London, 1807, vol. i, p. 138.
The parasites of the _Rhinoceridæ_ have been even less studied than
those of elephants. In 1856 Prof. Peters described a tapeworm from
Bruce’s rhinoceros (_R. Africanus_), which he named _Tænia gigantea_.
In 1870 Dr Murie, under the provisional name of _T. magna_, published
a description of the strobile of the same cestode from an Indian
rhinoceros (_R. unicornis_). From a total misconception of the character
of the proglottides, Murie was led to suppose that the segments of
the strobile were very deep as well as broad; whereas the proglottids
are remarkably narrow, thus partaking of the characters of the Tæniæ
of the larger herbivora in general. In a subsequent paper Peters
pointed out these errors. Murie had, in fact, rolled several segments
into one. In 1877 Professor Garrod encountered the same cestode in
_Rhinoceros sondaicus_, and, following Peters’ example, separated it
from the Tæniæ proper (_Plagiotænia gigantea_). The idea of generically
separating tapeworms possessing a more or less striking breadth of
strobile is not one which commends itself to my view, seeing that
many of the tapeworms of herbivora closely resemble the rhinoscerine
cestodes in this respect. As Diesing hints, this tapeworm comes near
to _T. perfoliata_, but Garrod’s and Peters’ figures both show that
_Plagiotænia_ wants the neck-lobes. The presence of cephalic appendages
may be regarded as generically distinctive, but it does not appear
that Blanchard separated the perfoliate tapeworm of the horse from the
Tæniæ proper on this ground. Therefore, in my account of the equine
tapeworms, I have not adopted his genus _Anoplocephala_. I may remark,
in passing, that if the distinctions, as between armed and unarmed, or
between proboscis-bearing (_Rhynchotæniada_) and non-proboscis-bearing
tapeworms (_Arhynchotæniada_), are to be maintained, they should
be expressive of divisional or subordinate value. Dr Weinland’s
arrangement, having reference to the thick- and thin-shelled ova
(Sclero- and Malaco-leptidota), is, perhaps, preferable. The whole
subject of classification requires revision, but it should be undertaken
by some helminthologists practically acquainted with a large number of
cestode types. As Garrod has well observed, _Plagiotænia_ enjoys a wide
geographical distribution, infesting alike Indian and African hosts.
Prof. Garrod, I observe, speaks of the _head_ of the mature tapeworm
as the _scolex_--an extension of the meaning of a term not usually
recognised. In this, however, he only follows Peters’ unfortunate
example.
The wide distribution enjoyed by Peters’ Plagiotænia is probably
equalled by that of the rhinocerine stomach-bot (_Gastrophilus
rhinocerontis_, Owen). This parasite was originally described in 1840,
and since that time it has been frequently encountered both in India
and Africa. To Mr Spooner Hart, of Calcutta, I am indebted for a large
number of specimens; their size exceeding that of any other bots that
have come under my notice. Probably this parasite infests the stomach of
rhinoceroses generally; at all events, it occurs in _R. unicornis_, _R.
bicornis_, and _R. simus_. At present the imago is unknown. The longest
larvæ in my possession measure 1-1/8″, but Brauer records specimens
up to 35 mm. in length by 10 mm. in thickness. In African hosts M.
Delegorgue found these parasites in prodigious numbers.
BIBLIOGRAPHY (No. 52).--_Brauer_, “Bot of the Rhinoceros,” ‘Monogr.
der Œstr.,’ 1863, s. 92.--_Cobbold_, “Note on Parasites presented
by Messrs Danford, Hart, and others,” ‘Veterinarian,’ 1875, p.
513.--_Coquerel_ and _Sallé_, in ‘Ann. Soc. Entom. de France,’ 1862
(quoted by Brauer).--_Delegorgue_, ‘Voyage dans l’Afrique’ (quoted by
Brauer).--_Garrod_, “On the Tænia of the Rhinoceros of the Sunderbunds
(_Plag. gig._, Peters),” ‘Proc. Zool. Soc.,’ Nov. 20, 1877, p.
788.--_Hope_, in ‘Trans. Entom. Soc.,’ 1840, p. 259.--_Joly, M. N._,
“Recherches Zool. (&c.) sur les Œstrides (&c.),” in ‘Ann. des Sciences
(&c.) de Lyon,’ 1846 (quoted by Brauer).--_Murie, J._, “On a probably
new species of Tænia (_T. magna?_) from the Rhinoceros,” ‘Proc. Zool.
Soc.,’ 1870, p. 608.--_Peters, W._, “Note on the Tænia from the
Rhinoceros, lately described by Dr J. Murie,” ‘Proc. Zool. Soc.,’ 1871,
p. 146.
Very little has been written respecting the parasites of the
_Hippopotamidæ_ and _Tapiridæ_. I think it was Livingstone who first
drew attention to the fact that the river-horse or sea-cow is much
infested by tapeworms, but I have not seen any published description of
the worm. Dr. Murie, during his sojourn in Egypt, found a solitary bot
embedded in the soft parts surrounding the eye, and judging from his
figure the species is new to science. Provisionally I speak of it as the
_Hypoderma Muriei_. In the paper (quoted below) Murie appends a list of
all the animals in which bots have been found. Though chiefly taken from
Brauer, it is useful and tolerably complete. So far as I am aware no
cestodes have been described as infesting tapirs; nevertheless, at least
five other kinds of helminth have been found in _Tapirus Americanus_.
Of these, two are flukes (_Amphistoma asperum_ and _A. pyriforme_),
and three are nematodes (_Sclerostoma monostechum_, _Spiroptera
mediospiralis_, and _Sp. chrysoptera_). The three species first named
occupy the cæcum, whilst the others are found in the stomach. According
to Molin’s description, both species occupy tuberous excrescences of
the mucous membrane, thus reminding us of the similar habit enjoyed by
_Sp. megastoma_ in the horse. The _Sp. chrysoptera_ is a comparatively
large species, the males measuring an inch, and the females as much as
an inch and a half in length. Both of the spiropteras were obtained from
tapirs by the indefatigable Natterer, _Sp. mediospiralis_ being also
procured by him from the aguti. If I have read Molin correctly, as many
as thirty-four examples of _S. mediospiralis_ were taken from a single
excrescence in the stomach of the tapir. Upwards of a hundred specimens
were procured, collectively, from three similar stomach-excrescences
in _Dasyprocta aguti_. These, and the other tapirine parasites above
mentioned, were originally discovered in Brazil.
BIBLIOGRAPHY (No. 53).--_Diesing_, “Neue Gattungen von Binnenwürmen
nebst einem Nachtrage zur Monographie der Amphistomen,” in ‘Annalen
d. Wien. Museums,’ Feb., 1839, s. 236.--_Idem_, ‘Systema,’ Bd. ii, s.
306.--_Molin_, “Una monografia del genere Spiroptera,” in ‘Sitzungsb.
der math.-naturw. Cl. d. k. Akad. d. Wissensch.,’ Bd. xxxviii, s. 1001,
1859.--_Murie_, “On a larval Œstrus found in the Hippopotamus,” ‘Proc.
Zool. Soc.,’ 1870, p. 78.
The osculant position of the anisodactyle pachyderms (_Hyracidæ_),
formerly classed as rodents, renders it desirable that their parasites
should be briefly noticed in this place. Probably these animals,
zoologically speaking, come nearest to the rhinoceroses, but Prof.
Owen showed that, anatomically, they possessed marked affinities with
the sloths. The klipdas or dasse (_Hyrax capensis_) is infested by a
tapeworm, of which hitherto the proglottides only appear to have been
seen (_Tænia hyracis_, Pallas). Under the name of _Cœnurus serialis_ a
larval cestode has been described by Gervais, the same parasite being
called _Arhynchotænia critica_ by Pagenstecher (“Zur Naturgeschichte
der Cestoden,” in ‘Sieb. u. Köll. Zeitschrift’). A variety of
nematodes have also been observed in the Cape hyrax. Of these, the
so-called _Physaloptera spirula_ is classed as doubtful by Molin and
Diesing. Hemprich and Ehrenberg furnished brief descriptions of four
other nematodes. Two of these worms were placed in the genus Oxyuris
(_O. pugio_ and _O. flavellum_), and the other two in the new genus
Crossophorus, which they formed for their reception (_C. collaris_ and
_C. tentaculatus_). The whole of these nematoids were obtained either
from the cæcum or large intestine.
An able article in the ‘Natural History Review’ for July 1865,
attributed to Professor Huxley, expressed very clearly the popular
notion as to the great danger of the flesh of swine considered as a
source of human parasites. No doubt the filthy pachyderms in question
(_Suidæ_) are much infested by helminths, some of which gain access to
man, but swine are neither attacked by a greater variety of entozoa
than other domesticated animals, nor are they so frequently a source of
human tapeworms as cattle. In the article above quoted the following
passage occurs:--“Of all animals, feral or domestic, the common pig is
beyond all doubt the most fertile source of human entozoa; at least, of
important parasites, _Trichina spiralis_ and the tapeworm would, there
is good reason to believe, cease to infest us, did not this favorite
quadruped act the part of a communicating medium.” This paragraph was
evidently written under the impression that “the tapeworm” most commonly
found in man was derived from the hog. So far back as 1864 I showed that
this was an entire mistake.
[Illustration: FIG. 66.--Head and neck of _Cysticercus_ from the Red
River hog. Magnified 60 diameters. Original.]
Flukes are rare in swine; nevertheless, _Fasciola hepatica_ and
_Distoma lanceolatum_ are occasionally present in the domestic hog,
and the peccaries (_Dicotyles_) are infested by an Amphistome (_A.
giganteum_). This large species, 3/4″ in length, formed the basis
of an admirable account of the anatomy of this genus of worms which
the learned Vienna helminthologist, Diesing, wrote before he was
deprived of his eyesight. The merits of that respected systematist’s
investigations have, I think, been much underrated, in consequence, no
doubt, of the artificial character of his system of classification.
For all that, his writings remain invaluable. Turning to the cestodes
of swine, there is not, so far as I am aware, any evidence of the
occurrence of sexually-mature tapeworms either in the hog or its allies;
but the frequency of larval cestodes, known as measles (_Cysticercus
telæ cellulosæ_), was well known to the early Jewish writers. In the
first part of this work I devoted as much space as I could spare to
the consideration of Cysticerci in general, and the pork-measle in
particular; but an exhaustive knowledge of the subject in relation
to hygiene can only be acquired by consulting the principal original
memoirs (quoted in the Bibliographies Nos. 13 and 14). In a Westphalian
ham, part of which was sent to me for examination, I calculated that
each pound of the flesh must have contained upwards of 600 Cysticerci.
I was informed by the donor, Dr Prior, that in spite of the disgusting
state of the meat much of it had been eaten by the well-to-do family
who purchased the ham. Cysticerci occasionally occupy the brain of the
pig in considerable numbers. Florman recorded a case of this kind where
their presence gave rise to vertigo in all respects resembling the gid
ordinarily produced by _Cœnurus_ in the sheep. As regards the larger
cestode larvæ, _Cysticercus tenuicollis_ and _Echinococcus veterinorum_
are of frequent occurrence. One not unfrequently encounters the former
in the mesentery, whilst the liver of the hog is sometimes so crowded
with hydatids that scarcely any of the glandular substance of the organ
remains visible. It is surprising how little the infested bearers
appear to be inconvenienced in such cases. In the winter of 1859, and
in the autumn of 1860, I found large cystic entozoa in an African
Wart-hog and in a Red River hog. These animals had died at the London
Zoological Society’s Menagerie; and as the worms appeared to me at the
time to be quite distinct from the ordinary slender-necked hydatid, they
were named, respectively, _Cysticercus phacochæri æthiopici_ and _C.
potamochæri penicillati_. The solitary example from the wart-hog was
found in a cyst near the colon; whilst of the five large bladder-worms
obtained from the Red River hog, one infested the liver and the other
four were lodged in the folds of the mesentery. The caudal vesicle of
the worm from the wart-hog measured 3-1/2″ in diameter, the vesicle of
the other bladder-worm being much longer. A reference to the original
figures will show that these forms are distinct. Swine are largely
infested by nematodes. The best-known form is _Ascaris lumbricoides_,
which Dujardin regarded as distinct (_A. suilla_). The hitherto disputed
identity of this worm with the human lumbricoid being no longer
questionable, the importance of the entozoon in relation to lumbricoid
endemics must at once be obvious; I have already, however, dwelt upon
this subject when treating of the human parasites. In like manner, the
subject of the flesh-worm disease, which is due to _Trichina spiralis_,
cannot be discussed in this place, as I have fully entered upon it
in connection with trichinosis in the human subject. What may be the
nature of the small threadworms found by Leidy in the extensor muscles
of the hog I cannot say, but Diesing inferred that they might represent
a distinct species (_Trichina affinis_). As regards the allied genus
_Trichocephalus_, the common species infesting swine (_T. crenatus_),
appears to be rarely absent. It not only infests the common domestic and
wild hog, but the peccaries and wart-hogs. These entozoa are probably
harmless to their bearers. In reference to them Krabbe says:--“When
the eggs are expelled with the excrement and pass into water, then the
embryos, after several months’ furlough, and there undergoing further
development, are transferred to the swine’s intestinal canal.” If I
rightly understand the paragraph (‘Husdyrenes Indvoldsorme,’ p. 28),
Krabbe states that the embryos are still within their egg-coverings when
infection takes place. The maw-worm of the hog is known as _Spiroptera
strongylina_. It was described and figured by Gurlt. The males measure
1/2″ and the females 3/4″ in length. Specimens of this worm were
supposed to have been found by Natterer in _Dicotyles albirostris_; but
it seems that the worms in question represent a distinct species, if
not an altogether new genus. In the year 1864 Professor Simonds placed
in my hands a very singular nematode, to which I gave the binomial
term _Simondsia paradoxa_. Numerous examples of this worm were found
by Prof. Simonds occupying cysts within the walls of the stomach of a
hog which had died at the London Zoological Society’s Menagerie. In my
introductory treatise I wrote of it as follows:--“The worm in question
has been regarded by Mr Simonds as a species of _Strongylus_, but I am
inclined to think that its affinities will place it nearer to the genus
_Spiroptera_. At present I have only examined the female, which is
characterised by the possession of a multitude of large tentacle-like
appendages surrounding the neck. These processes, by their aspect,
remind one of the so-called branchial projections on the back of
_Eolis_, but in this worm I believe them to be special folds formed for
the lodgment of unusually developed uterine organs. The female worm is
about 3/4″ in length.”
In the interval that has elapsed I have been unable to supply further
particulars, and unfortunately the original drawings of the worm
have been lost. The habits of the parasite remind us of _Spiroptera
megastoma_ infesting the walls of the stomach of the horse. Not
improbably this singular entozoon may turn out to be identical with
Molin’s _Spiroptera sexalata_, and if so, it may correspond with
_Spiroptera strongylina_. However, Diesing afterwards recognising, as
I had done, the desirability of separating this last-named worm from
the Spiropteræ proper, formed for it his new genus _Physocephalus_. He
then called the worm _Physocephalus sexalatus_. If, as is probable,
my _Simondsia_ and Diesing’s _Physocephalus_ are identical, the
species found by Simonds ought to be recognised by the generic title
which Diesing proposed. His genus was established about four years
before I described my _Simondsia_. Diesing was evidently led up to
the recognition of the generic distinction of the worm by Molin’s
examination and description of the worm. As, in my original account
of the worm found by Simonds, I spoke of numerous appendages to the
neck, it is evident that further investigation is necessary to clear
up the question of identity. According to Molin and Diesing the male
_Spiroptera sexalata_ measures rather beyond 1/4″ and the female beyond
1/2″ in length. Neither Diesing nor Molin speak of Natterer’s worms as
being found encysted. In fact they were free. Molin simply remarks:--“Io
ne esaminai in oltre 6 esemplari maschi e 77 femine raccolti in parte
dal muco che revestiva le pareti dello stomaco, ed in parte dal pasto
contenuto nello stesso organo di un _Dicotyles albirostris_ femina ai 24
Aprile, 1826.” After all that has been said it may be that my _Simondsia
paradoxa_ and Diesing’s _Physocephalus sexalata_ are quite distinct,
and that like the large- and small-mouthed maw-worms of the horse
(_Spiroptera megastoma_ and _S. microstoma_) they play a corresponding
rôle. Before very long I hope to set this question definitively at rest.
Passing to the strongyloid nematodes one of the most remarkable and
important species is _Stephanurus dentatus_. In the ‘Annalen des Wiener
Museums’ for 1839 (s. 232) this worm was first described by Diesing,
who employed the generic title as expressive of the crown-like figure
of the tail of the male worm. Diesing wrote as follows:--“At Barra do
Rio Negro, on the 24th of March, 1834, Natterer discovered this peculiar
genus of worms occurring singly or several together in capsules situated
amongst the layers of fat in a Chinese race of _Sus scrofa domestica_.
The males measure from ten to thirteen lines long, the females from
fifteen to eighteen lines, the former being scarcely a line in breadth
at the middle of the body, whilst the latter are almost a line and
a half in thickness. The curved body thickens towards the tail, is
transversely annulated, and viewed with a penetrating lens is seen to be
furnished with integumentary pores. The oral aperture opens widely. It
is almost circular, and is supplied with six teeth at the margin. Two of
these standing opposed to one another are larger and stronger than the
rest. The tail of the male, when spread out evenly, is surrounded by a
coronet of five lancet-shaped flaps; the combined flaps being connected
together from base to apex by means of a delicate transparent membrane.
The single spiculum situated at the extreme end of the tail projects
slightly forward and is surrounded by three skittle-shaped bodies. The
tail of the female is curved upon itself, rounded off, and drawn out at
the extreme end into a straight beak-shaped point; whilst to both sides
of the stumpy caudal extremity of the body short vesicular prominences
are attached. The female reproductive outlet occurs at the commencement
of the second half of the body. Thus, judging by its external characters
this genus is most closely allied to _Strongylus_.” In reproducing
Diesing’s description I have here rendered the translation somewhat more
freely than in my previous record of the discovery given in ‘Nature’
(1871). The original description is supplemented by a brief account of
the internal anatomy of the worm.
So far as I am aware no subsequent notice of this entozoon appeared
until the year 1858, when Dr J. C. White gave some account of a “find”
made in the United States. This re-discovery was reported in the sixth
volume of the ‘Proceedings of the Boston Natural History Society.’ Dr
White says:--“The worms were found in the leaf-yard of an apparently
healthy hog, in the adipose tissue near the kidney. They occupied a
space of the same about the size of a man’s fist and had burrowed
through the mass in every direction, forming canals three or four
millimètres in diameter, which terminated in cysts. On cutting open
these cavities, which did not communicate with each other, they were
found filled with pus, and in each were two worms, male and female.” Dr
White expresses his opinion that the worms gained access to the tissues
“by boring through the circulatory system while in the embryonic
condition.” I think that Dr White deserves great credit for his correct
diagnosis of the species, and all the more so because he was evidently
not acquainted with Diesing’s original memoir. He expressly speaks
of the “scanty descriptions” hitherto given of the worm. As Dr White
had accurately determined the species in the presence of an American
Scientific Society, it is remarkable that neither Verrill nor Fletcher
should have identified the worm.
On the 10th of January, 1871, I received a letter from Prof. W. B.
Fletcher, of Indianapolis, Indiana, U.S.A., and in it he announced that
he had “found a worm” infesting the hog. The parasite was so abundant
in swine that he obtained it in “nine out of ten hogs” which he had
examined. Dr Fletcher sent me specimens of the worm for description
and identification, when I at once recognised them as examples of
Diesing’s _Stephanurus dentatus_. As Dr Fletcher’s first communication
to myself was undated I do not know precisely when he first encountered
the worm, but it was in 1870. In that same year Prof. Verrill received
specimens of the worm. He says that they were received from Dr J. C.
White. Failing to identify the parasites as _Stephanuri_, Verrill
(making no allusion to the ‘Proceedings of the Boston Society’) not
unnaturally supposed he had to deal with an entozoon that was new to
science. Accordingly he immediately described and figured the worm
under the combined title of _Sclerostoma pinguicola_. If these data
are correctly given, the re-discovery of the worm in America was due
to Dr J. C. White; its identity with _Stephanurus_ being subsequently
acknowledged by Diesing, and afterwards, quite independently, by
myself. I gather this partly from Diesing’s ‘Kleine helminthologische
Mittheilungen’ (s. 281), published as a supplement to his ‘Revision
der Nematoden’ (1860-61). Until quite recently Diesing’s recognition
of the identity of White’s parasites with Stephanuri was unknown
in America. My conclusions arose from an examination of the actual
specimens, whereas Diesing was entirely guided by White’s description.
In this connection, moreover, a still more interesting re-discovery
remained to be recorded. The original announcement which I made in
the ‘British Medical Journal’ for January 14th, 1871, was followed
by another in the same periodical for September, 1871. As stated in
my second letter and repeated in my notice of Krabbe’s memoir on
“Parasites” (‘London Medical Record,’ April 2, 1873), the President
of the London Microscopical Society (through Mr Slack, who was at
that time the secretary) forwarded to me a box of microscopic slides
received by the Society from Australia. The slides displayed parasites
of various kinds. Having been requested to identify the parasites I had
the good fortune to recognise amongst them characteristic examples of
_Stephanurus dentatus_. Thus was first made known the fact that this
singular genus was not confined in its geographical distribution to the
two American continents, but that it extended to Australia. The order of
the principal “finds” and descriptions may therefore be thus restated.
Natterer discovered the worm in Brazil in 1834. Diesing described it in
1839. Dr J. C. White re-discovered and identified the worm in 1858. It
was subsequently found by Dr N. Cressy and by Dr Fletcher. These three
observers all encountered the parasite in the United States (1858-70).
Prof. Verrill re-described the worm as new to science in September,
1870. Diesing confirmed White’s diagnosis in 1860. I identified the worm
from Fletcher’s “find” in 1871. Dr Morris supposed he had discovered
a new entozoon in Australia in July, 1871. The Australian worms were
identified by me as examples of _Stephanurus dentatus_ in October, 1871.
The importance of _Stephanurus_ in relation to porcine epizoöty and the
supply of animal food cannot be ignored. As remarked in my communication
to ‘Nature,’ it must be quite obvious that so large a parasite, when
present in the hog in any considerable numbers, would give rise to
serious disease, even if it were not productive of fatal results to
the bearer. In one of his numerous communications to myself, Prof. W.
B. Fletcher writes as follows:--“It is my opinion that this parasite
is the cause, in some way, of the hog cholera, which has created such
sad havoc within the past ten years over the pork-producing parts of
America. One farmer told me, a few days ago, that within a month his
loss alone from this cause was over one hundred head; and sometimes,
in one neighbourhood, in a few days’ time, thousands have perished,
although this season is not a cholera year, as our farmers say. I
advised one farmer to burn or bury the dead animals, but he informed
me that he believed that fewer hogs die of the disease after eating
the dead animals than those kept from them. Unfortunately, in this
State there is no law guarding the spread of disease, neither is there
any reward of reputation or gain for pursuing any investigation that
would bring pork and beef packers into disrepute. I myself could not
get a pig’s kidney or beef’s liver in our city market, because I made
investigations in some Texas cattle (being cut up in our market), which
damaged their sale a few years ago.” In a third letter Dr Fletcher
tells me that greater facilities for examining the carcases of hogs
had since been accorded him through the liberality of a Liverpool
firm of pork-packers, who had already killed 75,000 hogs during the
summer season, _i.e._ up to the date of the first week in July. In hot
weather the slaughtering is conducted in ice-houses. Prof. Fletcher’s
views receive confirmation from the statements made by Dr Morris, who
speaks of the pigs as dying from some mysterious disease, and thinks
that the worms may be the cause of the porcine mortality. Writing to
the President of the London Microscopical Society from Sydney (July
12th, 1871), Dr Morris says:--“It is just possible that some pigs may
survive the irritation such a swarm of young worms must set up; others,
again, may die from peritonitis, hence the sudden deaths amongst the
pigs.” I think Dr Morris’ view is perfectly correct, but whether it be
so or not, it is (as observed by me in ‘Nature’) interesting to notice
the remarkable correspondency of the conclusions arrived at by Drs
Fletcher and Morris independently. It will probably not be difficult
to ascertain hereafter whether or not the maladies respectively termed
“hog cholera” and “mysterious disease” are one and the same disorder,
but whatever happens in this respect, it is now quite clear that this
parasite, hitherto little regarded, and for many years past persistently
overlooked, is extraordinarily prevalent in the United States, and,
perhaps, equally so in Australia; it being further evident that its
presence in the flesh of swine is capable of producing both disease and
death. The statement of the worthy American farmer that the swallowing
of infested flesh by pigs does not necessarily involve the pig-eating
hog in a bad attack of the so-called “cholera disease” requires to
be further tested, and it also remains to be proven whether or not
the _Stephanurus_ be capable of passing through all its developmental
changes from the egg to the adult form within the body of the bearer
without having at some time or other gained access to the outer world.
The comparatively large size of the ova, which I find to be about
1/105″, or more than four times the size of Trichina-eggs, is not
without significance, but as yet we are entirely unacquainted with the
larvæ of _Stephanurus_. If no intermediary bearers are necessary to its
development, we ought not to have to wait long for a complete record
of the life-history of _Stephanurus dentatus_. In conclusion, I will
only further remark that since thousands of hogs are infested by this
entozoon the subject is worth further investigation. I believe that
Prof. Fletcher brought the matter under the notice of the United States
National Swine Breeder’s Association, which met at Indianapolis in
November, 1872, but with what success I have been unable to learn. The
wealthy agricultural societies of Great Britain pay little or no regard
to the subject of parasites, although thousands of valuable animals
annually perish from the injurious action of entozoa.
Of the remaining nematodes infesting swine I must particularly mention
_Sclerostoma_ (_Strongylus_) _dentatum_ and _Strongylus paradoxus_,
the last named being generally regarded as identical with Dujardin’s
_S. elongatus_. The first of these two parasites infests the small
intestines, the male and female worms alike measuring about 1/2″ in
length. The females are sometimes a trifle longer. The _Sclerostoma
dentatum_ is an abundant parasite, infesting all varieties of swine and
also peccaries; but it is apparently incapable of serious injury to the
bearer. Schneider selected the male _S. dentatum_ for classificatory
purposes. In this worm the arrangement of the rays of the hood is
simple, forming a good central type. Dr D. V. Dean, in his excellent
report of St Louis Board of Health (1874), speaks of _Strongylus
dentatus_ as if it were the same entozoon as _Stephanurus_. The
confusion of nomenclature would have been avoided if Diesing had called
the renal worm _Stephanurus Nattereri_. I hope this title will yet be
adopted to prevent future mistakes. The lung-worm (_S. paradoxus_) is
by no means harmless, being a frequent cause of fatal husk in young
pigs. It is a viviparous worm, the females acquiring a length of 1-1/2″,
whilst the males rarely exceed 3/4″. Under the title _Gongylonema
pulchrum_, Molin has noticed yet another filariform nematode infesting
the wild hog; and, lastly, the lamented Russian traveller, Fedschenko,
has published a full description of a new species of Gnathostoma (_G.
hispidum_), which infests the coats of the stomach alike of the wild
and domestic hog. One of the most interesting parasites of swine is the
large acanthocephalous entozoon (_Echinorhynchus gigas_). It infests
the small intestines both of the wild and domesticated hog, and it
was also obtained by Natterer from the collared peccary of Tayazou.
Common as the great Echinorhynchus is in the United States (and it
is scarcely less so on the Continent) I believe that few, if any, of
the museums in the United Kingdom of Great Britain contain this large
entozoon. It is a curious fact that it does not exist in the Hunterian
Collection, where, however, there is displayed a very fine set of
acanthocephalous parasites from whales. When in the year 1865 I mounted,
with my own hands, 200 preparations of entozoa for the Museum of the
Royal College of Surgeons, I had not so much as seen a specimen of
this worm. Much scientific interest attaches to this parasite from the
fact that Schneider discovered that the embryos of _E. gigas_ take up
their residence in the larvæ of the cockchafer (_Melolontha vulgaris_).
He thinks it identical with the _Echinorhynchus hominis_ of Lambl.
Leuckart disputes this identity, and compares Lambl’s worm with the
_Echinorhynchus angustatus_ of our fresh-water fishes. The _E. spirula_
of certain Brazilian monkeys and of the Barbary ape bears a strong
resemblance to the species from the hog. On the strength of Lambl’s
case--and it is the only genuine instance of the kind on record--Prof.
Leuckart devotes no less than 125 pages of his great work to the
consideration of the structure and development of the thorn-headed
intestinal worms. This worm demands especial attention. Speaking of
the hog’s Echinorhynchus, Prof. Verrill, in his ‘Connecticut Report,’
says that “sometimes the intestine of a hog is found perforated by so
many holes that it cannot be used in the manufacture of sausages.” From
Mr George Wilkins I learn that the pig-slaughterers of our English
metropolis are well acquainted with these perforations, which are
sometimes so numerous that the gut looks as if it had been “riddled”
with swan-shot. No wonder that diseased hogs, afflicted with these
formidable parasites, go about, as Verrill expresses it, “continually
squealing and grunting, especially in the morning.” That they are
also “cross and morose, and given to biting and snarling at their
companions,” is by no means astonishing. “In severe cases,” remarks
Verrill, “hogs afflicted with this parasite are weak in the loins, and
have the membranes in the corners of the eyes swollen, watery, and
lighter colored than usual.” It is some comfort to know that Lambl’s
human case is unique, and that so long as people abstain from eating
cockchafer larvæ they are not likely to be infested by _Echinorhynchus
gigas_. In the first book of this work I have given my reasons for
not regarding Welch’s “encysted _Echinorhynchus_ in man” as a genuine
example of this curious genus of entozoa.
The external parasites of swine are not so numerous as might be
expected from the habits of their hosts. The most common ectozoon is
the hog louse (_Hæmatopinus suis_). This disgusting little insect is
about 1/8″ in length. Almost equally common is the hog mite. Though
hitherto considered as a distinct species (_Sarcoptes suis_, Gurlt),
it is regarded by Mégnin as a mere variety of _Sarcoptes scabiei_. As
Gerlach and others have remarked, it is readily transmissible to man.
The _Sarcoptes squammiferus_, of Fürstenburg, is only another name
for this variety of _S. scabiei_. Speaking of this scab-insect Mégnin
says:--“This parasite was first encountered by Spinola and Gurlt, and
afterwards by Müller.” He then adds:--“A Ceylon wild boar died at the
menagerie of the Museum of Paris of a chronic affection of the skin
which had transformed its integument into a vast _lichen_.” Lastly, as
regards the protozoal parasites I can only remark that the psorosperms
(spoken of as Rainey’s corpuscles or as Miescher’s utricles) are often
very abundant in the flesh of otherwise perfectly healthy swine.
Having dwelt upon the character of such organisms in the first moiety
of this work, I will only remark that the full significance of these
singular bodies yet remains to be determined. Rainey’s notion that they
represented early stages of cysticercal growth is altogether untenable.
According to Behrens, as quoted by Davaine, psorosperms are especially
abundant in the flesh of swine which have recovered from the disease
called _mal rouge_. On the subject generally, the writings of Rivolta,
Waldenburg, Eimer, and Siedamagrotsky are especially trustworthy. Full
references to these and other authorities are given in the synopsis of
the 2nd edition of Davaine’s well-known treatise.
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Measles, of the Pig,” from ‘Scottish Farmer and Horticulturist,’
in ‘Edin. Vet. Rev.,’ p. 688, 1861.--_Ballard, E._, “On Diseased
Meat, and what to observe in cases of suspected Poisoning by Meat or
Sausages (infected with Entozoa, &c.),” ‘Med. Times and Gaz.,’ Jan.,
1864.--_Bowditch, H. J._, “Raw Pork as an Aliment (without reference
to the question of Entozoa.--T. S. C.),” ‘Boston Med. and Surg.
Journ.,’ vol. lv, 1857; see also ‘Comments,’ vol. lvi, pp. 23 and
69, 1857.--_Cobbold_, “On the Discovery of Stephanurus in the United
States and in Australia,” in ‘Nature,’ Oct. 21, 1871, p. 508, and
in ‘Brit. Med. Journ.,’ Jan. and Sept., 1871; also in the ‘Monthly
Micros. Journ.,’ Nov., 1871.--_Idem_, “Internal Parasites of the
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Wart-Hog and Red River Hog,” ‘Proc. Zool. Soc.,’ 1861.--_Idem_, “On
Simondsia,” ‘Entoz.,’ p. 79.--_Idem_, “Note on Worms in the Lungs
of a Pig,” in the ‘Field’ for Jan. 9, 1864.--_Idem_ (in relation to
Cysticerci or Measles, see Bibl. Nos. 13 and 14, and, for remarks
on psorosperms, Bibl. No. 41).--_Cressy, N._, ‘On the Diseases of
Domestic Animals in Connecticut (2nd and 3rd Ann. Reports),’ Hartford,
U.S., 1873-74.--_Idem_, “The demands of Agriculture on Veterinary
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1872.--_Fleming, A._, “Measly Pork as Food for Man,” ‘Edin. Vet. Rev.,’
vol. i, p. 485, 1858-59.--_Idem_, “On the Measle of the Pig, and on
the Wholesomeness, as Food for Man, of Measly Pork,” ‘Dubl. Quart.
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in ‘Vetensk. Acad. Nya Handlingar,’ 1810, pp. 179-182.--_Gairdner,
W. T._, “Case of Tapeworm occurring in connection with the Eating of
Raw Pork,” ‘Edin. Month. Journ.,’ 1856, and in the ‘Veterinarian,’
vol. xxix, p. 228, 1856.--_Gamgee, J._, “On Diseased Meat,” ‘Pop.
Science Rev.,’ Jan., 1861.--_Gordon_, “On Tapeworm from Unwholesome
Food,” ‘Med. Gaz.,’ 1857.--_Gross, S. D._, “Note on the frequency
of Acephalocysts in Swine at Cincinnati,” in his ‘Elements of Path.
Anat.,’ p. 118, 1845.--_Gurlt, E. F._, ‘Lehrbuch der path. Anat. der
Haus-Saügethiere,’ 1831, s. 46, 51, 142, 385.--_Heller_ (see Bibl. No.
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review in ‘Lond. Med. Rec.,’ April 2, 1872, p. 206).--_Leidy_, “Note on
_Trichina spiralis_ from the Pig,” from ‘Rep. Acad. Philad.,’ in ‘Ann.
Nat. Hist.,’ vol. xix, 1847.--_Leuckart_ (see Bibl. No. 13).--_Lewis_
(Bibl. No. 13).--_Martin, J._, “Case of Hydatids in the Liver of a Sow,”
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14).--_Molin_, ‘Una Monog. del Gen. Spiroptera,’ Wien, 1860.--_Morris_,
“Report on Australian Parasites,” ‘Month. Microsc. Journ.,’ Nov.,
1871.--_Percy, S. R._, “On Diseased Meat in relation to Public Health
(Prize Essay),” ‘New York Med. Journ.,’ 1866.--_Idem_, “On the Food
of Cities (an Address),” ‘New York,’ 1864.--_Perroncito_ (Bibl. No.
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