52 Tht Descent of Man. Part I 



many actions it is indispensable that the arms and whole upper 

 part of the body should be free ; and he must for this end stand 

 firmly on his feet. To gain this great advantage, the feet have 

 been rendered flat ; and the great toe has been peculiarly modi- 

 fied, though this has entailed the almost complete loss of its 

 power of prehension. It accords with the principle of the 

 division of physiological labour, prevailing throughout the 

 animal kingdom, that as the hands became perfected for pre- 

 hension, the feet should have become perfected for support and 

 locomotion. With some savages, however, the foot has not 

 altogether lost its prehensile power, as shewn by their manner 

 of climbing trees, and of using them in other ways. 71 



If it be an advantage toman to stand firmly on his feet and to 

 have his hands and arms free, of which, from his pre-eminent 

 success in the battle of life, there can be no doubt, then I can see 

 no reason why it should not have been advantageous to the 

 progenitors of man to have become more and more erect or 

 bipedal. They would thus have been better able to defend 

 themselves with stones or clubs, to attack their prey, or other- 

 wise to obtain food. The best built individuals would in the 

 long run have succeeded best, and have survived in larger 

 numbers. If the gorilla and a few allied forms had become 

 extinct, it might have been argued, with great force and apparent 

 truth, that an animal could not have been gradually converted 

 from a quadruped into a biped, as all the individuals in an 

 intermediate condition would have been miserably ill-fitted 

 for progression. But we know (and this is well worthy of 

 reflection) that the anthropomorphous apes are now actually in 

 an intermediate condition ; and no one doubts that they are on 

 the whole well adapted for their conditions of life. Thus the 

 gorilla runs with a sidelong shambling gait, but more commonly 

 progresses by resting on its bent hands. The long-armed apes 

 occasionally use their arms like crutches, swinging their bodies 

 forward between them, and some kinds of Hylobates, without 

 having been taught, can walk or run upright with tolerable 

 quickness ; yet they move awkwardly, and much less securely 

 than man. We see, in short, in existing monkeys a manner of 

 progression intermediate between that of a quadruped and a 



74 Hack el has an excellent dis- foot as a piehensile organ by man ; 



cussion on the steps by which man and has also written on the manner 



became a biped: ' Natiirliche Schbp- of progression of the higher apes, to 



fungsgeschichte,' 186S, s. 507. Dr. which I allude in the following 



Btichner (' Conferences sur la Th^orie paragraph : see also Owen (' Anatomy 



Darwinienne,' 1869, p. 135) has of Vertebrates,' vol. iii. p. 71) on 



given good c^ses cf the ise cf the this latter subject. 



