INTRODUCTION 3 



face in the water was not really another monkey. And the end of 

 this realization was to be man." 



The dawn of consciousness alone can have been the beginning of 

 that curiosity which has led man for ages to attempt the explana- 

 tion of the world about him, and himself. Nothing in the world 

 has been more baffling in this pursuit than the thing called life. 

 Is it some force or quality distinct from all else, or is it merely the 

 product of other forces? Is it divine, or is it an earthly thing? 

 Shall we ever be able to explain it, or must it alwaj^s remain a great 

 mystery? Whatever may be the answer. Philosophy will continue 

 its attempts to explain and Biology its investigations, and if 

 nothing more accrues, they will at least have clarified our under- 

 standing and increased our store of facts. 



It is only natural that in other lives, particularly in very different 

 lives, this spirit of curiosity should find a major stimulus. Animals 

 were competitors of primitive man for the bounties of the earth 

 in various ways. Thej^ must often have used food which he him- 

 self desired, and others must have been ready at any moment to 

 use man himself as food. They must have contributed to his diet 

 early in his existence, and when domesticated they became not 

 only a more important l3ut a more intimate part of his life. They 

 must, as a result of these varied contacts, have impressed them- 

 selves upon him as a conspicuous part of his environment. We can 

 imagine a first scientist pioneering in comparative anatomy as he 

 picked the bones of game at his fireside. He might note that both 

 fish and bird have that peculiar jointed axis of bones which we call 

 the spinal column, and might wonder why they should be so dif- 

 ferent in other ways and so nearly alike in this. He might see the 

 same thing in a rabbit, and the evident resemblance between its 

 legs and the wings of the bird, superficially so different. Or in his 

 chance contacts afield he might wonder why the deer, so different 

 in many ways, should have hair like man and the rabbit, while the 

 bird has feathers and the fish, scales. Out of an infinite accumula- 

 tion of such observations, leading step by step to greater powers of 

 observation and increasing possibilities for inteq^retation, has 

 developed the science of Biology, and out of an insatiable desire 

 to explain these relationships of different organisms, all united by 

 the possession of that unknown thing called life and in varying de- 

 grees by peculiarities of organization, has come our recognition of 

 that process of nature which we call evolution. 



