QUADRUPEDS. 



329 



foot can never be anything else than an instrument of loco- 

 motion. In the Apes and Monkeys, the feet become 

 hands ; all of them having a thumb set on a different line 

 from the other toes, and susceptible of being opposed to 



Hands of 

 a. Bat: b. Mole; c. Dolphin. 



them, whereby the prehensile power is immensely increased, 

 and the capabilities of the organ are greatly varied. 



In all these cases, all of the extremities are of the same 

 form, but there are some in which the fore and hind feet 

 differ from each other. Thus, in the Bats, while the hind 

 feet have five short clawed toes, the fore ones have the first 

 four fingers immensely lengthened, like the ribs of an um- 

 brella, across which a delicate membrane is stretched, and 

 thus the fore limbs become organs of flight. And in Man, 

 who, by his organic nature, comes into this Class, the feet 

 are merely fitted for walking, while the anterior extremi- 

 ties, forming hands incomparably more delicate and more 



