60 COMPARISONS OF STRUCTUEE m ANDULS. 



and eacli protected at tlie tijDs with a strong 

 hard hoof; these hoofs are short, and pointed 

 at the tip, and are hooked down somewhat 

 like a claw ; they are compressed laterally, 

 and the upper surface presents an acute ridge, 

 sloping off on each side. The under surface is 

 linearly concave, and consequently adapted for 

 catching hold of any rugosity or projection. 

 The llama's foot is thus fashioned as an instru- 

 ment for clinging, or gaining a sort of hold in 

 difficult passes, and this structure enables the 

 animal to proceed with a free and fearless step. 

 As in the camel the limbs are meagre, yet the 

 llama will carry a weight of about one hundred 

 pounds, and travel for foui- or five leagues a 

 day. 



So far have we hastily traced the modifica- 

 tions of the anterior limbs as they present 

 themselves in ordinary quadrupeds. "We find 

 that when we descend the scale from man, 

 though, in many instances, the paws or 

 graspers retain a prehensile power, they cease 

 to be organs of tact or touch. What, indeed, 

 would the lower animals gain by such organs ? 

 what to them are the nicer quahties of matter 

 to be learned by this sense ? what have they 

 to do with those unnumbered operations, to 



