The Zoologist— June, 1868. 1241 



minuteness of the male sexin another large group of the same family. 

 In the genus Nephila, which contains some of the giants of the spider 

 race, the males are almost unknown, and where known they are 

 ridiculously disproportionate in size to the females. In Nephila 

 (Epeira) opuntiae, one of the most numerous spiders in Egypt, and in 

 parts of Syria and Palestine, the female measures from a half to three- 

 quarters of an inch in length, while the male does not exceed one- 

 tenth of an inch. This species is gregarious and very abundant, 

 young trees of the date palm, the prickly pear and gum acacia being 

 often in a perfect maze of web, in which thousands of the spiders live 

 in apparent amity : with the closest search, however, I only suc- 

 ceeded in obtaining three adult male specimens, so difficult was it 

 to detect them among the multitudes of yonng individuals of the 

 other sex. 



Two species of this group, figured and described by M. Vinson 

 (' Araneides des iles de la Reunion, Maurice et Madagascar,' pp. 183 

 — 191, plates v. and vi.), Epeira inaurata and E. nigra, present an 

 equally striking difference in the relative size of the sexes. In his 

 observations on the latter species he says, " Rien de plus disparate 

 que de voir la petitesse du male de l'Epeire noire, aupres du volume 

 enorme de la femelle; il se promene sur elle, marche sur ses cotes, 

 fait rapidement en se laissant glisser le long de ses longues pattes 

 comme le long d'un cable, lorsqu'il redoute sa colere. 11 se refugie 

 sur le milieu de son dos pour echapper a son atteinte. : . ." 



In this passage we are reminded of the well-known voracity of the 

 female spider in our common species, of the same family, Epeira 

 diadema, in which there is also a great disproportion in the relative 

 size of the sexes, though nothing so great as in the species to which 

 M. Vinson refers. The remarks of this author also lead me to suppose 

 that this extreme disproportion may be accounted for by an applica- 

 tion of Mr. Darwin's principle of "sexual selection." Thus the 

 smaller the male individuals the more chance they would have of 

 escaping the ferocity of the female, by playing at hide and seek 

 among her limbs and over her body in the mode M. Vinson describes. 

 This " selection " would go on exercising its inevitable influence upon 

 the size of the males until at length they became what in M. Vinson's 

 instances they appear to be — mere parasites upou the female: the 

 indefinite diminution of the male would only be checked by the 

 natural requirement of a certain size for the fulfilment of the offices 

 of impregnation. 



SECOND gEELES — VOL. HI. 2 F 



