ClI AP. XII. 
FISHES. 
19 
e vidence on this head. We can see that one sex will 
n °t be modified through natural selection for the sake 
of protection more than the other, supposing both to 
Vai 'y > unless one sex is exposed for a longer period 
to danger, or has less power of escaping from such 
danger than the other sex ; and it does not appear that 
"ith fishes the sexes differ in these respects. As far as 
there is any difference, the males, from being generally 
smaller size, and from wandering more about, are 
ex posed to greater danger than the females ; and yet, 
' v ken the sexes differ, the males are almost always the 
^ost conspicuously coloured. The ova are fertilised 
Bnmediately after being deposited, and when this pro- 
Cess lasts for several days, as in the case of the salmon , 30 
the female, during the whole time, is attended by the 
n ' ale - After the ova are fertilised they are, in most 
cases, left unprotected by both parents, so that the 
ma les and females, as far as oviposition is concerned, 
are equally exposed to danger, and both are equally 
11,1 P°i' taut for the production of fertile ova ; consequently 
the more or less brightly-coloured individuals of either 
Sex would be equally liable to be destroyed or pre- 
Sei 'ved, and both would have an equal infiuenco on the 
c °l°urs of their offspring or the race. 
Certain fishes, belonging to several families, make 
lles ts ; and some of these fishes take care of their 
•° Un g when hatched. Both sexes of the brightly- 
coloured Crenilabrus massa and melons work together in 
nilding their nests with sea-weed, shells, &c . 31 But the 
tt'ales 0 f certa j n fi s ] ieg ( | 0 a il the work, and afterwards 
d ve exclusive charge of the young. This is the case 
m Y arrell > ‘ British Fishes,’ vol. ii. p. 11. 
e . '“- CC01 'ding to the observations of M. Gerbe; see Gunther’s ‘Ke- 
°f Zoolog. Literature,’ 1865, p. 194. 
