246 'i^aiS JJKSCENT OF MAN. 



have been much struck by the apparently enormous preponder- 

 ance of the males." Thus Mr. Bates,"' In speaking of several spe- 

 cies, about a hundred in number, which inhabit the Upper Ama- 

 zons, says that the males are much more numerous that the fe- 

 males, even in the proportion of a hundred to one. In North 

 America, Edwards, who had great experience, estimates in the 

 genus Papilio the males to the females as four to one; and Mr. 

 Walsh, who informed me of this statement, says that with P. 

 turnus this is certainly the case. In South Africa, Mr. R. Trimen 

 found the males in excess in 19 species;™ and in one of these, 

 which swarms in open places, he estimated the number of males 

 as fifty to one female. With another species, in which the males 

 are numerous in certain localities, he collected only five females 

 during seven years. In the island of Bourbon, M. Maillard states 

 that the males of one species of Papilio are twenty times as nu- 

 merous as the females.'' Mr. Trimen informs me that as far as he 

 has himself seen, or heard from others, it is rare for the females 

 of any butterfly to exceed the males in number; but three South 

 African species perhaps offer an exception. Mr. Wallace™ states 

 that the females of Ornithoptera 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, GuenSe 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 attributed by various observers to the 

 more retiring heabits 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 i-e.marks, the males of the domesticated 

 Bombyx Yamamai, are useless at the beginning of the season, and 

 the females at the end, from the want of mates.*' I cannot, how- 

 ever, persuade myself that these causes suffice to explain the 



■'''lyeuckart quotes Melnecke (WagTier, 'Handworterbuch der Phys.' 

 B. iv. 1853, s. 775) that the males of Butterflies are three or four times 

 as numerous as the females. 



'5 'The Naturalist on the Amazons," vol. ii. 1863, pp. 228, 347. 



" Four of these cases are given by Mr. Trimen in his 'Rhopalocera 

 Africae Australis.' 



" Quoted by Trimen, 'Transact. Ent. Soc.,' vol. v. part iv. 1866, p. 330. 



™ 'Transact. Linn. Soc.,' vol. xxv. p. 37. 



" 'Proc. Bntomolog. Soc," Feb. 17th, 1868. 



80 Quoted by Dr. Wallace in 'Proc. Ent. Soc.,' 3rd series, vol. v. 1867, 

 p. 487. 



