Chap. VIII. 
SEXUAL SELECTION. 
817 
this, I believe, could be effected through natural selec- 
tion in the manner hereafter to be described. The 
same train of reasoning is applicable in the above, 
as well as in the following case, if we assume that 
females instead of males are produced in excess, for 
such females from not uniting with males would be 
superfluous and useless. So it would be with poly- 
gamous species, if we assume the excess of females 
to be inordinately great 
An excess of either sex, we will again say of the 
males, could, however, apparently be eliminated through 
natural selection in another and indirect manner, namely 
by an actual diminution of the males, without any in- 
crease of the females, and consequently without any 
increase in the productiveness of the species. From 
the variability of all characters, we may feel assured 
that some pairs, inhabiting any locality, would produce 
a rather smaller excess of superfluous males, but an 
equal number of productive females. When the off- 
spring from the more and the less male-productive 
parents were all mingled together, none would have any 
direct advantage over the others ; but those that pro- 
duced few superfluous males would have one great 
indirect advantage, namely that their ova or embryos 
would probably be larger and finer, or their young- 
better nurtured in the womb and afterwards. We see 
this principle illustrated with plants; as those which 
bear a vast number of seed produce small ones ; whilst 
those which bear comparatively few seeds, often produce 
large ones well-stocked with nutriment for the use of the 
seedlings . 73 Hence the offspring of the parents which 
73 I have often been struck with the fact, that in several species of 
Primula the seeds kd the capsules which contained only a few were 
very much larger than the numerous seeds in the more productive 
■capsules. 
