228 Heredity. 



tcction of her brood, and for her own defence while in- 

 cubating, as the cock's spurs and ornaments are in an- 

 other way to him: nor can we doubt that such organs 

 would be preserved and perfected by natural selection 

 if proper variations should appear and should become 

 hereditary. 



Among the mammalia the peculiar organs of the male, 

 his so-called secondary sexual characters, are often of 

 great use to him in ways which are not connected with 

 reproduction. This is especially true of his weapons of 

 offence, for the bull not only uses his horns in fighting 

 with other males for the females, but also in protecting 

 himself and the rest of the herd from enemies. The 

 elephant uses his tusks in many ways. He tears down 

 trees with them for the sake of the foliage, and he rips 

 open palm trees in order to obtain the nutritious farina- 

 ceous core. He uses them to prod the ground to discover 

 whether it is firm enough to bear his weight, and with 

 them he attacks and kills his enemies. Many mountain 

 goats, when they accidentally fall from great heights, 

 strike upon their strong and elastic horns, and thus 

 break the force of the blow. In fact, most of the weap- 

 ons which occur in male animals are used for defence 

 or protection, as well as in their conflicts with other 

 males. The presence of these organs often saves the life 

 of their possessor, and it would therefore seem as if they 

 would be more modified by natural selection than by 

 sexual selection, for natural selection usually means 

 death to the unarmed male, while the result of sexual 

 selection is simply a decreased number of descendants. 

 But natural selection acts upon the female as well as the 

 male, and as the care and protection of the young usually 

 falls to the female mammal, it would seem as if she ;is 

 well as the male ought to have special weapons of de- 



