36 COMPARISONS OF STRUCTURE IN AiraiALS. 



address ; and the animals are said to introduce 

 it into the hollows and fissures of trees, iu 

 order to hook out eggs, which they relish as 

 food. The naked portion of the prehensile 

 tail of the Australian phalangers is also highly 

 sensitive. 



In all the ape and monkey tribes, the arms 

 are proportionally longer than in man: but 

 there is considerable difference among them. 

 In the orang and gibbons, the arms are so long 

 that when the animals stand in an erect 

 position they nearly touch the ground; the 

 hands too are of extreme length, while the 

 hinder limbs are greatly abbreviated ; but, in 

 the baboons, which are far more terrestrial in 

 their habits, and never attempt to assume an 

 erect posture, there is more equahty between 

 the anterior and posterior limbs. In many, 

 the fore-arm greatly exceeds the upper-arm, or 

 humerus, in length, and of the two bones of 

 the fore-arm that called the radius, on which 

 the pronation and supination of the hand 

 depend, is the stoutest, a condition the reverse 

 of that which we find in the human skeleton. 

 As a rule the blade-bones are far more lateral 

 than in man, and the clavicles or collar-bones 

 are shorter and straighter. Such, then, are 



