316 
THE PRINCIPLES OP 
Part 
cases an inequality would be no advantage or disa«' 
vantage to certain individuals more than to others; and 
therefore it could hardly have resulted from natural 
selection. We must attribute the inequality to tk e 
direct action of those unknown conditions, which wit* 1 
mankind lead to the males being born in a somewhat 
larger excess in certain countries than in others, ° r 
which cause the proportion between the sexes to di& eI 
slightly in legitimate and illegitimate births. 
Let us now take the case of a species producing fro# 1 
the unknown causes just alluded to, an excess of on 1 ' 
sex — we will say of males — these being superfluous 
useless, or nearly useless. Could the sexes be equalised 
through natural selection ? We may feel sure, from 
characters being variable, that certain pairs would pi 0, 
duce a somewhat less excess of males over females tha» 
other pairs. The former, supposing the actual numh er 
of the offspring to remain constant, would necessarily 
produce more females, and would therefore be more pi®" 
ductive. On the doctrine of chances a greater numW 
of the offspring ot the more productive pairs would su 1 ' 
vivo ; and these would inherit a tendency to procrea*® 
fewer males and more females. Thus a tendency t0 " 
wards the equalisation of the sexes would he brougO 
about. But our supposed species would by this proces* 
be rendered, as just remarked, more productive; an 1 * 
this would in many cases be far from an advantage* 
for whenever the limit to the numbers which exist, <1®' 
peuds, not on destruction by enemies, but on the atnoU 1 ^ 
of tood, increased fertility will lead to severer comp®* 1 " 
tion and to most of the survivors being badly fed. I 11 
this case, if the sexes were equalised by an increase & 
the number of the females, a simultaneous decrease i 11 
the total number of the offspring would be beneficial > 
and this, I believe, could be effected through natura 
