108 NEW YORK ZOOLOGICAL SOCIETY. 
caused by the abstraction of blood: from the intestinal mucosa 
from the action of these parasites. One of the most frequent of 
these intestinal parasites found in the animals of the dog family 
is the ankylostoma duodenale, a worm chiefly found in the duo- 
denum, where it attaches itself to the mucous membrane by hook- 
like spikes with which it is provided. These parasites often give 
rise to severe anzmias, “Egyptian Chlorosis’ of man being 
caused by its presence. It has been shown that it may remain 
in the intestine for a long time after the primary infection. The 
eges of the parasite are oval shaped, and enter the intestine 
through infected food or drink; here they undergo partial de- 
velopment, and leaving the gut develop still further in foul water. 
Entering the intestine again through this means they develop 
into sexually mature parasites, and the ove are then discharged 
in the feces of the infected animals. 
CESTODES 
Of various types are frequent in the intestines of the animals 
at the Park; in several instances death has been caused by them. 
They are particularly frequent among the snakes, notwithstanding 
the care which is exercised in the selection of food for these ani- 
mals. These parasites always enter in infected meat. 
There can be no doubt but that the intestinal parasites fre- 
quently induce conditions at least predisposing to the develop- 
ment of fatal disease, hence care should be exercised in the pre- 
vention of this infection. This can in a measure be carried out 
by inspection of the stools of recently acquired animals before 
they are admitted to general enclosures. Frequently also when 
the parasites are found in the feces, if the attention of the veter- 
inarian be called to the fact, proper treatment may relieve the 
animal and prevent the extension of the disease to other animals. 
It is self-evident that all food should be inspected for parasites. 
In last year’s report I mentioned the finding of the mischer- 
schen schleuche (Rainey’s corpuscles) in the heart-muscle of one 
of the elk, where it created sufficient disturbance to cause the 
death of the animal. It was mentioned at this time that, accord- 
ing to the literature on the subject, invasion of the myocardium ° 
by the parasite is rare, and it is generally looked upon as inno- 
cent in most cases. This view of the parasite has been advanced 
by Ostertag, and is endorsed by such authorities as Pfeiffer and 
Ziegler. These investigators do not consider it as highly infec- 
tious, and Pfeiffer was unable to infect animals experimentally. 
Pfeiffer’s conclusions have, however, been disproven by the re- 
