INTRODUCTION 41 
conditions may thus be understood. It is also not 
unreasonable to expect that alterations observed as 
natural responses in a large number of specimens in 
nearly normal surroundings would serve as more reliable 
guides to investigative speculation than would changes 
in a few animals under artificial technical experimenta- 
tion. We hope that the few facts we have been able to 
record may afford someone a basis for further biological 
studies. It is also to be hoped that something has been 
learned which in the end will afford an explanation of the 
diseases of man. Too great optimism in this direction 
should be guarded against because the human being is 
indeed an animal sui generis and, from the standpoint of 
normal conditions of nature, a wild animal. 
The zoological classification found on pages 43-46 
was compiled in 1903 by Dr. A. E. Brown on the basis of 
the British System. With a few exceptions the computa- 
tions in the text are made on the basis of zoological 
orders since the number of specimens in families is often 
too small and the complications of so many different 
figures would be confusing. The tables will be found to 
correspond to the sequence of the classification. 
Dr. Corson- White has, however, used for her analysis 
the dietary groupings. A carnivore in her chapter 
implies strictly a meat-eater, in the rest of the book one of 
the zoological group Carnivora. 
The Laboratory of Comparative Pathology at this 
Garden speaks for the earnest desire on the part of the 
Directors to use the material to its fullest extent, and I, 
acting for myself and my associates, wish to record our 
appreciation of the facilities offered to us for study, and 
for the broad-minded, scientific cooperation the Board has 
always displayed. The President, Charles B. Penrose, 
M.D., Ph.D., LL.D., was the active originator of the plan 
whereby this department was started, and he has given to 
it continuously the support of his rich experience. I wish 
to express for myself the deepest appreciation of his 
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