THE SEXES, AND CRITICISM OF SEXUAL SELECTION. 



25 



In regard to horns, feathers, and the hke, in association 

 with vigorous circulation, two sentences from Rolph may be 

 quoted: — " The exceedingly abundant circulation, which peri- 

 odically occurs in the at first soft frontal protuberances of 

 stags, admits and conditions the colossal development of horn 

 and delicate ensheathing velvet. ... In the same way, 

 the rich flow of blood in the feather papillae conditions the 

 immense growth of the feathers, . . . and the same is true 

 of hairs, spines, and teeth." 



I\lale {c), Worker (^b), and Queen («) Ant. — From Cha7nbers's Enoyc, after Lubbock. 



Some of the even subtler differences between the sexes are 

 of interest in illustrating the general antithesis. Thus in the 

 love-lights of the Italian glow insect {Luciola\ the colour is 

 said to be identical in the two sexes, and the intensity is much 

 the same. That of the female, however, who is in other repects 

 rather male-like in her amatory emotions, is more restricted. 

 It is interesting further to notice, that the rhythm of the light 

 in the male is more rapid and the flashes are briefer, while that 

 of the female is longer and the flashes more distant and tremu- 

 lous. This illustration may thus serve, in conclusion, as a 

 literally illumined index of the contrasted physiology of the 

 sexes. 



§ 5. Sexual Selection : its Limit as an Explanation. — W^e 

 are now in a better position to criticise Mr Darwin's theory. 

 On his view, males are stronger, handsomer, or more emo- 

 tional, because ancestral forms happened to become so in a 

 slight degree. In other words, the reward of breeding success 



