32 
the pro ventricle, just as does that fatal parasite of birds, 
Spiroptera incerta. This one, however, induces no tissue 
changes, and furthermore it cannot be producing any 
important toxic substance to interfere notably with the 
host's health, because the ova of this parasite were found 
over eight years ago in the dejecta of our concave horn- 
bill (still living) and during that time the infestation has 
not caused any symptoms. 
Uncinariasis: — There has been one case of hookworm 
disease this year, i. e., in a Red Fox (No. 5681). 
Hepaticola hepatica: — There has been but one develop- 
ment this year in this subject which has been investi- 
gated (and remarked in the annual reports) here for the 
last four years; but it is an important one because it 
indicates extension of the disease. Now a beaver (No. 
5547) has come to autopsy with an infestation of its 
liver almost as extreme as any we have seen in the prairie 
dogs and white rats which we have experimentally in- 
fested or which have contracted the disease spontane- 
ously. The course of the disease down-hill from the 
prairie dog enclosure to the beaver dam (water-borne?) 
may explain the extension, or it may have been a direct 
one from the rats just as the prairie dogs contracted it. 
This is the first time the beaver has been reported as 
affected by the parasite. 
Amoebic Spider Monkeys: — This year the sole survivor 
of last years dysentery enzootic died. Amcebic cysts 
had been found in the animals stools, it had been quaran- 
tined, and treated with emetine and nutmeg. At autopsy 
only the healed scars of the ulcers remained, i. e., the 
beast had recovered from his amoebic infection. We are, 
from this, inclined to think the better of nutmeg as a 
therapeutic agent; and we give credit to it rather than 
to emetine because amcehce were still found in the stools 
after the course of emetine treatment. 
We mention in passing that a spider monkey newly 
arrived in the Garden showed no amcebic structures in 
the stool. 
