84 THE ENTOMOLOGIST. 



The President mentioned that Mr. Darwin was engaged in 

 elaborating the snbjecl of" secondary sexual diffevences and 

 sexual selection, and would be obliged by the comnuinication 

 of detailed observations on the numerical proportion of the 

 sexes of insects in nature. He had numerous cases of well- 

 authenticated numerical excess of the n)ale over ihe female, 

 and was desirous to ascertain whether in other cases a co- 

 responding excess of the female over the male had been 

 noticed. 



Mr. M'Lachlan mentioned Apatania Mulrebris, of which 

 he had captured hundreds, but the male had never been 

 seen ; and Boreus hiemalis, of which only three or four 

 males had been known to occur in this country. Mr. 

 Janson mentioned Tomicus villosus, the female of which 

 was ahnost a plague, whilst tlie male was hardly known. 

 Mr. S. Stevens referred to Drilus flavescens, the second 

 known British female of which was exhibited at the 

 previous Meeting (' Entomologist,' iv. 81). Mr. F. Smith cited 

 Tenthredo cingulatus, the male of which was rare, whilst the 

 female abounded, and Hemichroa AIni, of which the male 

 was quite unknown. Of the latter Mr. Smith had a large 

 number of cocoons, and if there were such a thing as a male 

 of that species he hoped soon to breed it. 



The President remarked that the different habits of the 

 sexes must be taken into account. Among the South - 

 American butterflies, the males of many were more handsome 

 than the females, and exceeded them in number in the pro- 

 portion of a hundred to one ; the male sported in the sun- 

 shine, whilst the female was slow in flight, never appeared in 

 in the open sun, but remained in the shade of the forest : 

 under such circumstances it might be that a superabundance 

 of males was necessary in order to ensure the impregnation 

 of ihe females and to prevent the extinction of the species ; 

 but he was unable to suggest any explanation of an excess 

 of females over males. 



Mr. Stainton thought that, by reason of the difference of 

 habit of tlie sexes, little reliance could be placed upon records 

 of a supposed disproportion of the number of the saxes of 

 any insect when in a state of nature : it was only by breeding 

 the insect that the relative numbers of the sexes could be 

 ascertained with any certainty. In Micro-Lepidoptera he 



