36 
SEXUAL SELECTION. 
Pabt II- 
first conjecture which will occur to every one is that 
they are used by the males for fighting together ; but 
Dr. Gunther, to whom I am indebted for the foregoing 
details, does not believe that such peacable crea- 
tures would ever become pugnacious. Hence we are 
with the previously-mentioned Cophotis and with the 
Acantliodactijlus capensis of S. Africa. In a Cordylus 
of the latter country, the male is either much redder or 
greener than the female. In the Indian Calotes nigri- 
labris there is a greater difference in colour between 
the sexes ; the lips also of the male are black, whilst 
those of the female are green. In our common 
little viviparous lizard ( Zootoca vivipara ) “ the under 
“ side of the body and base of the tail in the male arc 
“ bright orange, spotted with black; in the female 
“ these parts are pale greyish-green without spots.” 4 ' 
We have seen that the males alone of Sitana possess a 
driven to infer that 
these almost mon- 
strous deviations 
of structure serve 
as masculine orna- 
ments. 
Fig. 36. Chameleon Owenii. Upper figure, male ; 
lower figure, female. 
With many kinds 
of lizards, the sexes 
differ slightly in co- 
lour, the tints and 
stripes of the males 
being brighter and 
more distinctly de- 
fined than in the 
females. This, for 
instance, is the case 
57 Bell, ‘ History of British Bepliles,’ 2nd edit. 1S49, p. 40. 
