SECTION XVIIl 
THE ANIMAL PARASITES, THEIR INCIDENCE 
AND SIGNIFICANCE 
Feed D. Weidman, M. D. 
It is quite to be expected that animal parasites would 
be found in the animals of zoological gardens, garnered 
as these beasts are from all parts of the world, tropical 
and other-wdse. It inevitably follows that many of the 
forms should be strange and new, enticing one to the 
fascinating determination of their identity, life history 
and hygienic importance ; and, developing from all this, 
one can easily imagine how limitless the opportunities 
are for scientific work in parasitology in a laboratory 
like ours. 
As in other biological fields, the taxonomic range of 
parasites here is wide. It extends from the lowly proto- 
zoa to the insecta, and, dropping to the smaller subdivi- 
sions, includes not only most of the genera familiar to 
human parasitology but many kno^vn only among the 
lower animals. From the standpoint of the host, the bio- 
logic state of parasitism extends from the lowest protozoa 
to homo. 
The above ^vill suflBce to indicate the vdde range of 
parasitism in animals, but the extent of work actually 
done thus far in ^\^ld animal material is a different story. 
Collated, consistent studies, so far as I am aware, have 
been undertaken only at the London Garden, here at 
Philadelphia, and at Washington, D. C, by Dr. Charles 
W. Stiles and Albert Hassal. The data collected by the 
last mentioned workers are incidental to the Index Cata- 
logue of Veterinary and Medical Zoology, and embrace 
only the (index) phase indicated by the title, but it is so 
valuable, and ^\'ithal so altruistic, that it must be credited. 
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