10 CONTROLLED NATURAL SELECTION 
have an advantage over other pairs, in which 
the chance of male and female surviving is 
equal. 
If the female be destroyed, the character of 
the female and the male will not be repro- 
duced; at any rate the chance of his, the 
male, reproducing himself is less than males 
in general, for he must find another mate. 
If the male be destroyed, it by no means 
follows that the male characters will be de- 
stroyed, for it is likely that he has already 
fertilised the female, especially as the society, 
a pair in the majority of animals, only occurs 
during the breeding season. 
Directly the percentage of males in the population 
become much reduced polygamy results, and the value 
of the male will rise until it equals that of the female: 
directly this balance is struck, further evolution of the 
male, making him more liable to be selected, will cease. 
Similarly with any other society of unequally valuable 
individuals, they will become marked according to their 
value, and in such a way that Natural Selection will be 
controlled and compelled to take the less valuable rather 
than the more valuable. 
A review of the exposition. Facts: 
1. Individuals of a species not of equal 
value : male and female, old and young. 
2. Individuals form themselves into so- 
cieties : pairs, families, herds, &c. 
