82 ZOOLOGY 



and future of the human race has always been a topic of 

 absorbing interest. The most superficial examination will 

 convince us that our bodies are constructed on the same general 

 plan as those of all other Vertebrata, and that all the argu- 

 ments used in favour of the blood-relationship of various groups 

 of Vertebrata with one another, apply equally strongly in 

 favour of the kinship of the human race with the higher 

 Vertebrata. We are typical Mammalia with a covering of 

 hair protecting our skins, a four-chambered heart and an 

 apparatus of sweat glands to regulate our temperature, and the 

 division of the Mammalia to which we show most resemblance 

 and with which we should undoubtedly be classed by an 

 intelligent visitor from Mars is the order of the Primates or 

 Monkeys. In fact, at the present day it may be confidently 

 asserted that there is no intelligent naturalist who is not con- 

 vinced that the human race is descended from monkey-like 

 ancestors ; and the quibbling objection which is sometimes 

 raised, that our ancestors could not have been identical with 

 any race of monkeys existing now, is entirely beside the point. 

 Our ancestors may have so closely resembled a race of monkeys 

 still living that they would have been included in the same 

 species. Yet it would in nowise follow that human beings 

 should in that case be in process of evolution now ; for, as we 

 have seen, a new species arises out of an old one through 

 spreading into a new environment : now the environment into 

 which an incipient new race of men would spread is fully 

 occupied by the present human race, and there is thus no room 

 for the development of any other race of man-like creatures 

 from living monkeys. 



When we come to examine where the environments of 

 monkeys and men differ, we find that much light is thrown 

 on the factors which led to the development of mankind. 

 Monkeys are tree-loving animals ; without exception the lives 

 of all species are passed in climbing from branch to branch, 

 and their descents to ground are quite exceptional, and 

 this applies equally to those monkeys like the Gorilla and 

 Chimpanzee, which most closely resemble man, as to those 

 lower races like the Spider-monkeys and Marmosets of 

 Brazil, which least resemble the human species. The human 

 race, in contrast with the monkeys, are Ground-Apes 



