CHAPTER II. 



TRACES OF UNITY IN THE LIMBS OF 

 VERTEBRATE ANIMALS. 



THE hand of man is in no sense a peculiar organ. It is 

 the foot ennobled : that is all. Moreover, a comparison 

 of the human hand and foot with the members corres- 

 ponding to them in other vertebrate creatures only leads 

 to the same conclusion by very many different ways. 



In the quadrumana, in place of two hands and two feet, 

 as in man, there are, as the name implies, four hands : and 

 very generally the two which correspond to the feet in 

 man are more handlike than the other two, in that the 

 great toe is larger and better fitted for acting after the 

 fashion of a true thumb. So also in the scansorial 

 lizards and in many birds. The chameleon, for ex- 

 ample, is a quadrumanous animal rather than a quad- 

 ruped, rivalling the monkey in its power of climbing 

 among the branches of trees : and the parrot, as is seen 

 in the way in which it continually handles its food with 

 one of its feet while it clutches at its perch with the 

 other, is quite as much a bimanous animal as a biped. 

 Indeed, the five-toed foot of the reptile and the four- 

 toed foot of the bird may be looked upon as more hand- 

 like than the hand as to thumb-power, for in both 

 the thumbs are doubled. 



In quadrupeds, on the contrary, the four hands of 

 the quadrumana are replaced by four feet : but even 



