XXIII. MAN, A MAMMAL 



XLI. </L study of man as a vertebrate compared 

 iritli tfiefrog- (Laboratory Manual, Prob. XLI.} 



(a) Comparison of body covering. 



(b) Tlie study of muscles. 



(c) Adaptations in the skeleton. 



(d) Nervous system. 



Man's Place in Nature. Although we know that man is sepa- 

 rated mentally by a wide gap from all other animals, in our study 

 of physiology we must ask where we are to place man. If we 

 attempt to classify man, we see at once he must be placed with 

 the vertebrate animals because of his possession of a vertebral 

 column. Evidently, too, he is a mammal, because the young are 

 nourished by milk secreted by the mother and because his body 

 has at least a partial covering of hair. Anatomically we find that 

 we must place man with the apelike mammals, because of these 

 numerous points of structural likeness. The group of mammals 

 which includes the monkeys, apes, and man we call the primates. 



Although anatomically there is a greater difference between' 

 the lowest type of monkey and che highest type of ape than there 

 is between the highest type of ape and the lowest savage, yet there 

 is an immense mental gap. 



Undoubtedly there once lived upon the earth races of men who 

 were much lower in their mental organization than the present 

 inhabitants. 



Evolution of Man. If we follow the early history of man upon 

 the earth, we find that at first he must have been little better than 

 one of the lower animals. He was a nomad, wandering from place 

 to place, living upon whatever living things he could kill with his 

 hands. Gradually he must have learned to use weapons, and thus 

 kill his prey, first using rough stone implements for this purpose. 

 As man became more civilized, implements of bronze and of iron 



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