106 THEORY OF THE EAKTH. 



may take place with regard to the horns of rein - 

 deer and stags. But let us compare two elephants 

 the most dissimilar, and we shall not discover the 

 slightest difference in the number and articula- 

 tions of the bones, the structure of the teeth, &c. 



Besides, the herbivorous species, in the wild 

 state, seem more restrained from dispersing than 

 the carnivorous animals, because the sort of food 

 which they require, combines with the tempera- 

 ture to prevent them. 



Nature also takes care to guard against the al- 

 teration of the species, which might result from 

 their mixture, by the mutual aversion with which 

 it has inspired them. It requires all the inge- 

 nuity and all the power of man to accomplish 

 these unions, even between species that have the 

 nearest resemblances. And, when the indivi- 

 duals produced by these forced conjunctions are 

 fruitful, which is very seldom the case, their fe- 

 cundity does not continue beyond a few genera- 

 tions ; and would not probably proceed so far, 

 without a continuance of the same cares which 

 excited it at first. Thus, we never see in our 

 woods individuals intermediate between the hare 

 and the rabbit; between the stag and the doe; or 

 between the martin and the pole-cat. 



But the power of man changes this order ; it 

 discloses all those variations, of which the type 



