40 THE EVOLUTION OF MAN 



the greater size of the cranium and the brain, the relatively 

 smaller and less projecting face, and the relatively and abso- 

 lutely longer lower extremities. Man does not differ much 

 more from the tailless apes, like the gorilla, than they differ 

 from the old-world tailed apes. 



Anthropologists generally agree that living man is repre- 

 sented by one genus Homo and a single species sapiens, and 

 that the various races are merely varieties of Homo sapiens. 

 Fossil remains of man have been found, as has been explained 

 in the previous chapter, which represent several other species 

 and which show marked ape-like characters. It is not certainly 

 known whether present man has evolved through these fossil 

 forms or whether they rather represent collateral lines now 

 extinct. 



The races differ notably in many parts of their bodies. The 

 most important differences are shown in the size and form of 

 the head, in the skeletal and physiognomic characters, in the 

 color of the skin, the form and color of the hair, and the body 

 proportions. There are also differences in the susceptibility 

 to disease and, although less marked, psychic differences 

 in the races, particularly as exhibited in the temperament. 

 The soft tissues likewise show racial differences although little 

 in regard to them is known. This subject offers a large field 

 for further investigation. It is possible also that the races 

 differ in protein reactions and hormones, as held by some au- 

 thorities, a subject as yet quite unexplored. 



Blumenbach's classification of the races is as satisfactory 

 as any, although the use of a single criterion of race distinc- 

 tion, namely, skin color, is open to objection. Blumenbach 

 classifies the races as follows: (i) Caucasian, having a white 

 skin, (2) Mongolian, having an olive skin, (3) Ethiopian, 

 having a black skin, (4) American, having a dark skin with 

 more or less of a red tint, (5) Malay, having a brown or 

 tawny skin. Some classifications include the Australians as a 



