346 Biology in America 



parently unconcerned beholder of the struggle, and then re- 

 tires with the conqueror. The war is, perhaps, severest be- 

 tween the males of polygamous animals, and these seem 

 oftenest provided with special weapons. The males of car- 

 nivorous animals are already well armed ; though to them and 

 to others, special means of defense may be given through 

 means of sexual selection, as the mane of the lion, and the 

 hooked jaw to the male salmon ; for the shield may be as im- 

 portant for victory as the sword or spear. 



Amongst birds, the contest is often of a more peaceful 

 character. All those who have attended to the subject, be- 

 lieve that there is the severest rivalry between the males of 

 many species to attract, by singing, the females. The rock- 

 thrush of Guiana, birds of paradise, and some others, congre- 

 gate; and successive males display with the most elaborate 

 care, and show off in the best manner, their gorgeous plumage ; 

 they likewise perform strange antics before the females, which 

 standing by as spectators at last choose the most attractive 

 partner. Those who have closely attended to birds in con- 

 finement well know that they often take individual prefer- 

 ences and dislikes : thus Sir R. Heron has described how a 

 pied peacock was eminently attractive to all his hen birds. 

 I cannot here enter on the necessary details; but if man can 

 in a short time give beauty and an elegant carriage to his 

 bantams, according to his standard of beauty, I can see no 

 good reason to doubt that female birds, by selecting, during 

 thousands of generations, the most melodious or beautiful 

 males, according to their standards of beauty, might produce 

 a marked effect." 2 



These various theories of animal color are unfortunately 

 mainly founded on an " anthropomorphic " basis. If it is 

 difficult for us to discover the frog in the grass or a lizard 

 on a stump, assuredly it must be so likewise to the natural 

 enemies of these creatures. If a butterfly or a toad has a 

 foul taste, or an unpleasant odor to man, it must impress 

 its enemies with the same unpleasant feature. If the white 

 tail of the rabbit renders him easier for us to follow as he 

 dashes away, it must also aid the young in their flight, to 

 keep near the mother. It does not follow however that be- 

 cause an object is difficult for man to see, it is likewise difficult 

 for the eye of bird or beast to follow it, or because another 

 object is unpleasant to man's senses, that it is also unpleasant 

 to those of the creatures of the wild. 



Recent experiments tend in particular to refute the theory 

 of warning color. This is based very largely, though not 



Darwin, " Origin of Species," 6th ed., pp. 108-109. By permission 

 of D. Appleton and Company. 



