338 
SEXUAL SELECTION. 
Paht II. 
thinks that, as a general rule, it is the male. Both 
sexes whilst young, as I am informed by the same 
author, usually resemble each other; and both often 
undergo great changes in colour during their successive 
moults before arriving at maturity. In other cases 
the male alone appears to change colour. Thus the 
male of the above-mentioned brightly-coloured Spa- 
rassus at first resembles the female and acquires his 
peculiar tints only when nearly adult. Spiders are 
possessed of acute senses, and exhibit much intelli- 
gence. The females often shew, as is well known, the 
strongest affection for their eggs, which they carry 
about enveloped in a silken web. On the whole it 
appears probable that well-marked differences in colour 
between the sexes have generally resulted from sexual 
selection, either on the male or female side. But doubts 
may be entertained on this head from the extreme 
variability in colour of some species, for instance of 
Theridion lineatum , the sexes of which differ when 
adult ; this great variability indicates that their colours 
have not been subjected to any form of selection. 
Mr. Biackwall does not remember to have seen the 
males of any species fighting together for the posses- 
sion of the female. Nor, judging from analogy, is this 
probable; for the males are generally much smaller 
than the females, sometimes to an extraordinary de- 
gree . 14 Had the males been in the habit of fighting 
together, they would, it is probable, have gradually 
14 Aug. Vinson (‘Araneides des lies de la Reunion , 3 * pi. vi. figs. 1 
•vnd 2) gives a good instance of the small size of the male in Epeira 
nigra . In this species, as I may add, the male is testaceous and the 
female black with legs banded with red. Other even more striking 
cases of inequality in size between the sexes have been recorded 
(‘ Quarterly Journal of Science/ 1868, July, p. 429); but I have not seen 
the original accounts. 
