178 DISEASE IN WILD MAMMALS AND BIRDS 
(4) The appropriateness of the food is a very impor- 
tant factor in the health of an animal under captive 
conditions. Diet lists are made up by officials largely 
according to the known habits and general physiology of 
an animal, but the food offered can at best only approxi- 
mate what the wild beast obtains for himself. It does not 
follow because a selected diet may seem to provide all the 
elements contained in the food available under natural 
conditions that it actually does so, especially since we are 
aware that some essential food factors, known under the 
term vitamins, are necessary to best development. These 
substances vary in closely similar foods, and seem to be 
higher in simple natural foods than in prepared diets. 
We have seen in this Garden that the inorganic constitu- 
ents must be correctly represented in the food, else 
degenerative osseous condition may develop. Inappro- 
priate diet may express itself at once after the receipt of 
an animal, by its sickness or death, or after some time in 
the development of chronic t^nnpanites, chronic intestinal 
catarrh or bony deformities. 
(5) The physical condition of food is a matter of no 
small moment. The taking of soft food in large quanti- 
ties especially by herbivorous animals, permits too short 
a sojourn in the gastric fundus and is often followed by 
pyloric and duodenal disease. Too firm food may pack 
the rumen, fundus or proventricle as the case may be, and 
be succeeded by distention of these parts and catarrh of 
the pyloric and intestinal area. The effect of foreign 
bodies mixed with food is difficult to evaluate unless of 
course they be of such a nature (pointed metal and the 
like) as directly to traumatize the mucosa. Many birds 
and mammals come to autopsy with a relatively large 
number of stones and small sticks in the stomach without 
any distinct evidence that they have been hurt thereby. 
In the bird the stones may be so large and numerous as to 
leave little room for food, or small enough to pass out into 
the intestine where they undoubtedly may pave the way 
