SEXUAL SELECTION 331 



females of Ornithopiera croesus, in the Malay Archipelago, 

 are more common and more easily caught than the males; 

 but this is a rare butterfly. I may here add, that in 

 Hyperythra, a genus of moths, Guen^e says that from 

 four to five females are sent in collections from India 

 for one male. 



When this subject of the proportional numbers of the 

 sexes of insects was brought before the Entomological 

 Society, " it was generally admitted that the males of most 

 Lepidoptera, in the adult or imago state, are caught in 

 greater numbers than , the females ; but this fact was attrib- 

 uted by various observers to the more retiring habits of the 

 females, and to the males emerging earlier from the cocoon. 

 This latter circumstance is well known to occur with most 

 Lepidoptera, as well as with other insects. So that, as 

 M. Personnat remarks, the males of the domesticated 

 Bombyx Yamamai are useless at the beginning of the sea- 

 son, and the females at the end, from the want of mates. '" - 

 I cannot, however, persuade myself that these causes suffice 

 to explain the great excess of males in the above cases of 

 certain butterflies which are extremely common in their 

 native countries. Mr. Stainton, who has paid very close 

 attention during many years to the smaller moths, informs 

 me that when he collected them in the imago state, he 

 thought that the males were ten times as numerous as the 

 females, but that, since he has reared them on a large scale 

 from the caterpillar state, he is convinced that the females 

 are the more numerous. Several entomolpgists concur in 

 his view. Mr. Doubleday, however, and some others take 

 an opposite view, and are convinced that they have reared 

 from the eggs and caterpillars a larger proportion of -males 

 than of females. 



Besides the more active habits of the males, their earlier 

 emergence from the cocoon, and in some places their fre- 

 quenting more open stations, other causes may be assigned 



" "Proc. Entomolog. Soc," Feb. 17, 1868. 



s» Quoted by Dr. Wallace in "Proc. Ent. Soc," 3d series, vol. v., ISST, p. 487. 



