214 Mr. S. B. J. Skertchly on the 



female sailed down with stately flight, showing her white spots 

 clearly, and commenced to woo. For a long time they circled 

 over us about 6 inches apart, the female always uppermost 

 and a little behind, so that she could see the emerald feathers 

 of her mate. She did all the wooing. The flight was a 

 sailing motion with a peculiar tremour of the wings, very 

 unlike the quivering while feeding. The female during the 

 whole time pointed her abdomen downwards. A solitary 0. 

 flavicollis was about and made several feeble attacks on the 

 lovers, which rhey totally ignored. At length they settled 

 high up in a tree and united, the female still uppermost. 



Darwin, dealing with the courtship of butterflies, draws the 

 conclusion that where the males are the brighter they are 

 chosen by the females and where the females are the hand- 

 somer the males are the selecting parties *. He says : '' Now 

 the males of many butterflies are known to support the females 

 during their marriage-flight ; but in the species just named 

 [C. edusa^ II. jonira, Pleris, Thecld] it is the females which 

 support the males ; so that the part which the two sexes play 

 is reversed, as is their relative beauty. Throughout the animal 

 kingdom the males commonly take the more active share iu 

 wooing, and their beauty seems to have been increased by the 

 females having accepted the more attractive individuals ; but 

 with these butterflies the females take the more active part iu 

 the flnal marriage ceremony, so that we may suppose that 

 they likewise do so in the wooing ; and in this case we can 

 understand how it is that they have been rendered more 

 beautiful." 



The case of O. Brookeana is the exact opposite of this. 

 The female is so much rarer than the male that Kiinstler, who 

 has caught over a thousand males, has taken only fifteen 

 females. Distant says " it is still exceedingly scarce " f. 

 The female is quite dull in comparison with her splendid 

 mate, yet she does all the wooing, or did in the case described, 

 which is probably a typical one. If sexual selection be really 

 a fact of evolution, this is a case in which it can work. Tiie 

 females have unlimited chances of selection, and the males may 

 be supposed to be only too glad to accept any lover. Indeed, 

 I can only imagine sexual selection acting where there is a 

 disparity of numbers between the sexes. Selection implies 

 rejection, and where the sexes are practically equal in number, 

 though the handsomer individuals may choose or be chosen 



* 'Descent of Man,' ed. 2, p. 819. 

 t Rhop. Mai. p. 331. 



