308 EVOLUTION, OLD AND NEW. 



pachyderms have five toes covered with horn ; some 

 four, some three. The ruminants, which appear to be 

 the earliest mammals that confined themselves to a life 

 upon the ground, have but two hooves, while the horse 

 has only one.* 



" Some herbivorous animals, especially among the 

 ruminants, have been incessantly preyed upon by car- 

 nivorous animals, against which their only refuge is in 

 flight. Necessity has therefore developed the light and 

 active limbs of antelopes, gazelles, &c. Kuminants, 

 only using their jaws to graze with, have but little 

 power in them, and therefore generally fight with their 

 heads. The males fight frequently with one another, 

 and their desires prompt an access of fluids to the parts 

 of their heads with which they fight ; thus the horns 

 and bosses have arisen with which the heads of most of 

 these animals are armed. \ The giraffe owes its long 

 neck to its continued habit of browsing upon trees, 

 whence also the great length of its fore legs as com- 

 pared with its hinder ones. Carnivorous animals, in 

 like manner, have had their organs modified in corre- 

 lation with their desires and habits. Some climb, some 

 scratch in order to burrow in the earth, some tear their 

 prey ; they therefore have need of toes, and we find 

 their toes separated and armed with claws. Some of 

 them are great hunters, and also plunge their claws 

 deeply into the bodies of their victims, trying to tear 

 out the part on which they have seized ; this habit has 

 developed a size and curvature of claw which would 

 impede them greatly in travelling over stony ground ; 



* 'Phil. Zool.,' torn. i. p. 253. f Pa g e 25*. 



