338 
SEXUAL SELECTION. 
Pabt 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 Spn* 
rassus at first resembles the female and acquires biS 
peculiar tints only when nearly adult. Spiders ate 
possessed of acute senses, and exhibit much intelb' 
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 ’ t 
appears probable that well-marked differences in colon 1 ' 
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 extreffl 0 
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. Blackwall does not remember to have seen th 0 
males of any species fighting together for the posses' 
sion of the female. Nor, judging from analogy, is tin- 
probable ; for the males are generally much smaH el 
than the females, sometimes to an extraordinary do' 
gree . 14 Had the males been in the habit of fightiu- 
together, they would, it is probable, have graduallj 
14 Aug. Vinson (‘Arane'ides des Ilea de la Reunion,’ pi. vi. fig 3- , 
and 2) gives a good instance of the small size of the male in 2 Vp ei 
nigra. In this species, as I may add, the male is testaceous and 4 
female black with legs banded with red. Other even more strik> D e 
cases of inequality in size between the sexes have been recon 
(‘ Quarterly Journal of Science,’ 1868, July, p. 429); but I have not see 
the original accounts. 
