SliXUAL COLORATION. 267 



«,re not even enough to prove the " recognition mark " view of 

 ■coloration ; they simply show that insects can recognise colour, 

 and perhaps prefer certain hues to others. The facts of 

 hybridisation may be also quoted as possible errors of recog- 

 ■nition on the part of Lepidoptera. 



Objections to the Theory of Sexual Selection. 

 It is quite common to see the peacock expand his tail and go 

 through all the performances incidental to courtship, while the 

 hen peacefully searches for food, quite uninfluenced by this 

 amatory display. It may be, however, that this is to be 

 explained simply by the fact that the hen is not in a mood to 

 respond to these advances. 



Excitability at Breeding Season of Animals among which there is 



no Pairing. 



It is not only animals which pair that show a departure from 

 their usual habits at the breeding season. The Palolo worm, 

 :greatly esteemed as an article of food by the Pacific islanders, 

 is an instance to the point. This worm, which is of a greenish 

 •colour, appears at certain seasons upon the surface of the sea ; 

 these times coincide with the maturity of the sexual products. 



Another instance of the same phenomenon has been recorded 

 Ijy Mr. Savile Kent. A marine worm belonging to the same 

 family as the Palolo appears in vast numbers in October ; after 

 ■a few hours of active movement on the surface, they entirely 

 •disappear from view. "By a close examination of these worms," 

 says Mr. Kent, " disporting upon the surface of the water, and 

 also isolated in suitable receptacles, and with the aid of the 

 microscope, I was fortunate in discovering the raison d'etre of 

 their early revels. It was, in fact, their general wedding 

 morn, and these their wedding junketings. Each worm was 



