DIVERGENCE OF CHARACTER 123 



one nation or district required swifter horses, whilst those of 

 another required stronger and bulkier horses. The early dif- 

 ferences would be very slight ; but, in the course of time, from 

 the continued selection of swifter horses in the one case, and 

 of stronger ones in the other, the differences would become 

 greater, and would be noted as forming two sub-breeds. Ul- 

 timately, after the lapse of centuries, these sub-breeds would 

 become converted into two well-established and distinct 

 breeds. As the differences became greater, the inferior ani- 

 mals with intermediate characters, being neither very swift 

 nor very strong, would not have been used for breeding, and 

 will thus have tended to disappear. Here, then, we see in 

 man's productions the action of what may be called the prin- 

 ciple of divergence, causing differences, at first barely appre- 

 ciable, steadily to increase, and the breeds to diverge in 

 character, both from each other and from their common 

 parent. 



But how, it may be asked, can any analogous principle 

 apply in nature ? I believe it can and does apply most effi- 

 ciently (though it was a long time before I saw how), from 

 the simple circumstance that the more diversified the de- 

 scendants from any one species become in structure, consti- 

 tution, and habits, by so much will they be better enabled to 

 seize on many and widely diversified places in the polity of 

 nature, and so be enabled to increase in numbers. 



We can clearly discern this in the case of animals with 

 simple habits. Take the case of a carnivorous quadruped, 

 of which the number that can be supported in any country has 

 long ago arrived at its full average. If its natural power of 

 increase be allowed to act, it can succeed in increasing (the 

 country not undergoing any change in conditions) only by 

 its varying descendants seizing on places at present occupied 

 by other animals; some of them, for instance, being enabled 

 to feed on new kinds of prey, either dead or alive ; some 

 inhabiting new stations, climbing trees, frequenting water, 

 and some perhaps becoming less carnivorous. The more 

 diversified in habits and structure the descendants of our 

 carnivorous animals become, the more places they will be 

 enabled to occupy. What applies to one animal will apply 

 throughout all time to all animals — that is, if they vary — for 



