Chap. XX.J SUMMARY. 367 



tific precision. He who does not admit this agency in 

 the case of the lower animals, will properly disregard all 

 that I have written in the later chapters on man. "We 

 cannot positively say that this character, but not that, 

 has been thus modified ; it has, however, been shown that 

 the races of man differ from each other and from their 

 nearest allies among the lower animals, in certain charac- 

 ters which are of no service to them in their ordinary 

 habits of life, and which it is extremely probable would 

 have been modified through sexual selection. We have 

 seen that with the lowest savages the people of each tribe 

 admire their own characteristic qualities — the shape of the 

 head and face, the squareness of the cheek-bones, the 

 prominence or depression of the nose, the color of the 

 skin, the length of the hair on the head, the absence of 

 hair on the face and body, or the presence of a great 

 beard, etc. Hence these and other such points could 

 hardly fail to have been slowly and gradually exagger- 

 ated from the more powerful and able men in each tribe, 

 who would succeed in rearing the largest number of off- 

 spring, having selected during many generations as their 

 wives the most strongly-characterized and therefore most 

 attractive women. For my own part I conclude that of 

 all the causes which have led to the differences in exter- 

 nal appearance between the races of man, and to a certain 

 extent between man and the lower animals, sexual selec- 

 tion has been by far the most efficient. 



