Habit and Instinct. 441 



as well as to the individual. Breeders of cattle wish the 

 flesh and fat to be well marbled together ; an animal thus 

 characterized has been slaughtered, but the breeder has 

 gone with confidence to the same stock, and has succeeded. 

 Such faith may be placed in the power of selection, that a 

 breed of cattle always yielding oxen with extraordinarily 

 long horns could, it is probable, be formed by carefully 

 watching which individual bulls and cows, when matched, 

 produced oxen with the longest horns ; and yet no one ox 

 would ever have propagated his kind. . . . Hence we may 

 conclude that slight modifications of structure or of instinct, 

 correlated with the sterile condition of certain members of 

 the community, have proved advantageous ; consequently, 

 the fertile males and females have flourished, and trans- 

 mitted to their fertile offspring a tendency to produce 

 sterile members with the same modifications. This process 

 must have been repeated many times, until that prodigious 

 amount of difference between the fertile and sterile females 

 of the same species has been produced which we see in 

 many social insects." 



Now let us apply this illustration to the case of habits 

 intelligently acquired. Instead of the possession of long 

 horns, suppose the performance of some habitual action 

 be observed in the oxen. Then, by carefully watching 

 which individual bulls and cows, when matched, produced 

 oxen which performed this intelligent habitual action, a 

 breed of cattle always yielding oxen which possessed this 

 habit might, on Darwin's principles, "be produced. The 

 intelligence of oxen might in this way be enhanced. Such 

 faith may be placed in the power of selection that a breed 

 of cattle <always yielding oxen of marked intelligence 

 could, it is possible, be formed by carefully watching which 

 individual bulls and cows, when matched, produced the 

 most intelligent oxen ; and yet no ox would ever have 

 propagated its kind. Eegarding, then, a nest of ants or 

 bees as a social community, mutually dependent on each 

 other, and subject to natural selection, that community 

 would best escape elimination in which the queen produced 



