SEVENTH ANNUAL REPORT. 115 
mals which take kindly to that provided. I may mention as ani- 
mals of this group especially the ruminants, and particularly if 
these animals be allowed to feed at will on the natural foods of 
their range in addition to receiving prepared fodder. In the nat- 
ural state these animals do not feed as undisturbed as in the Park, 
but must be constantly on the lookout, rendering constant feeding 
impossible. Coupled with this natural method is a large amount 
of exercise which the beasts must take in the securing of their 
food. During inclement weather their rations are doubtless often 
reduced to a minimum. Thus we find in nature that the amount 
of food is generally limited, and that the procuring of it requires 
the expenditure of a considerable amount of energy. At the same 
time the foods selected by the animals are naturally those de- 
signed for them by nature, varying according to natural require- 
ments. In captivity almost opposite conditions obtain. The 
- amount of food is generally too great, unless absolutely under 
the control of keepers, as with the carnivora or such omnivora 
as the bears. The amount of exercise necessarily expended in 
the securing of the food is reduced to a minimum, and finally the 
inclosures of the animals are generally so limited in extent that 
sufficient exercise is not encouraged. We may conclude more 
or less confidently that animals are very much like man and are 
not inclined to do more than the necessary amount of labor, suf- 
ficient to provide them with food and comfort. It is well known 
that the most healthy people are those who earn their food under 
proper hygienic conditions by abundant physical exercise. In 
captivity, in most cases, the foods cannot be selected with the 
strict adherence to the demands of each peculiar animal as in 
the open. 
These factors, improper alimentation coupled with insufficient 
physical exercise, throw on the excretory and absorbtive struct- 
ures of the body increased work, accompanied generally with a 
diminished oxidation. Digestive and other metabolic disturb- 
ances follow, and metabolic toxins are thrown into the circula- 
tory fluids exciting parenchymatous and fatty degeneration of 
the parenchyma cells, accompanied by the arterio-sclerosis and 
interstitial hyperplasia. I believe that we may not inaptly com- 
pare these conditions to those of high living men, and the results 
on the body tissues are the same in both instances. 
Resulting from these lesions we have a general lowering of 
the tone and resistance of the body. This condition predisposes 
to many infective diseases, of which doubtless pneumonia is the 
most frequent. The condition is well exemplified in the preva- 
