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CHAPTER XLIII 

 MAN'S PLACE IN NATURE 



Man the Apex of the Animal Series. — If the pres- 

 entation of the facts and principles of biology given in 

 this book has accomplished its purpose, it should be clear 

 in the mind of the reader that no sharp line separates 

 man from other living creatures. The world of nature 

 presents a vast array of forms, varying in complexity, but 

 all having a common basis of protoplasm and all show- 

 ing a high degree of adjustment to their environment. 

 Man is without doubt the most highly specialized of 

 them all, and yet his metabolic processes are essentially 

 like theirs. Man occupies, then, a definite position in 

 nature. The fact that his position is at the peak of the 

 scale of development should not cause man to lose sight 

 of the fundamental fact that he is a part of the order of 

 nature and is subject to the same laws by which the 

 activities of other living things are controlled. 



Man's Similarity to the Higher Animals. — From 

 what has been said in previous sections of this book it 

 should be clear that in physical constitution man differs 

 only slightly from many of the higher animals. His 

 plan of bodily structure is the same as that of mammals 

 generally. Except for a few details, his physical structure 

 is strikingly similar to that of the highest mammalian 

 groups, the monkeys and apes. The fundamental basis 

 of nervous functioning in man is — so far as we can 

 learn — precisely similar to that of other mammals, and 

 in fact, of all except the most lowly animals. In man as 

 in other animals simple reflexes, complex reflex actions, 

 the properties of memory and association, form the basis 



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