MENTAL AND PHYSICAL RESULTS. 259 



grade of mental activity, and the most marked difference between 

 the ages of the fathers and mothers. With the Arabs, Turks, and 

 the higher casts of the Hindus, we also have classes of bearded 

 men who habitually have wives much younger than themselves. 



While the beard is not of itself a functioning character, and 

 consequently is not influenced by use or disuse, it grows upon the 

 face and is dependent upon sexual maturity, as we see from the 

 fact that a eunuch raises little or no beard. Our beardless boy- 

 father is a sexually immature person, and while he transmits sexual 

 intensity, he also transmits sexual immaturity, and in a few gen- 

 erations this sexual 'immaturity will exhibit itself by a lack of that 

 character which is developed from maturity. 



SECONDARY SEXUAL CHARACTERS IN LOWER ANIMALS. 



This illustration of the beard on a man is typical of a long line 

 of secondary sexual characters which appear in the lower animals. 

 Darwin has pointed out that polygamous animals exhibit the greater 

 number and most marked of secondary sexual characters, and he 

 ascribes their existence to selection. While admitting that perhaps 

 selection plays a part in this matter, I feel confident that the abso- 

 lute or relative age of the male plays a more important part. We 

 know that as long as the male lives the sexual characteristics 

 become more and more pronounced, and we also know that the 

 polygamous male who is the head of a considerable harem is a 

 vigorous old male, the younger males being either killed or driven 

 away. The younger females are under no such disadvantages, and 

 as a consequence the disparity in age between the male and the 

 female is very marked. With monogamous animals there is no 

 reason why the average age of males and females should differ 

 much, and we find little difference between the sexes, though 



