EIGHTH ANNUAL REPORT. 109 
as in our previous experience with this disease, the undoubted 
cause was the cropping of the grass which grows in the enclosures. 
From our observations there can be no doubt but that the propo- 
sition made in an earlier report must be complied with before we 
are reasonably free frorn it; that is, that the entire food and water 
supply of all the animals, particularly of the native Herbivora, 
must be placed immediately under the control of the keepers. It 
is worse than useless, after our experience, to attempt to furnish 
a natural food supply within the ranges. The complete absence 
of fatal gastro-enteritis among the Primates, whose food and 
water supply has been very carefully supervised during the past 
year, entirely demonstrates the benefits guaranteed by these 
methods. 
PARASITIC DISEASES. 
Deaths from parasitic diseases have been much reduced during 
the past year, only 7 fatalities arising from this cause. This fa- 
vorable result, in the case of intestinal parasites, in my opinion is 
mostly due to the fact that, under the direction of your Veterina- 
rian, vermifuges have been systematically employed, and often- 
times the result has been the voiding of large numbers of para- 
sites, fortunately before the animal had been directly killed by the 
parasites, or before they had set up a serious gastritis or enteritis. 
This one fact alone places far beyond question any doubt as to 
the value of medicinal treatment of wild animals in captivity, for 
animal men tell us that intestinal parasites are among the most 
serious factors with which they have to deal, and certainly our 
experience before these methods were introduced bears out this 
idea. One badger died as the result of intestinal nematodes, but 
no fatal cases of tenia infection have occurred during the past 
season. 
Cysticerci—There has been a marked diminution in the number 
of cases exhibiting cysticerci and hydatid cysts. During the past 
year but two cases were found, while, as I mentioned in a previous 
report, at one time these cysts were present in nearly every case 
dying in the Park. Doubtless this year’s records in regard to this 
have been partly a matter of good fortune, but it is also certain 
that the general methods of cleanliness, now so universally en- 
forced about the animal enclosures, has reduced the number of 
infections occurring in the Park itself. The careful supervision 
of the food is also doubtless a factor; however, I do not believe 
that it will ever be possible to eradicate the disease entirely, since 
