288 SECRETS OF ANIMAL LIFE 



it in performing bipedal dogs and bears. But 

 bipedal progression is one thing and the upright 

 position is something more. The problem is : What 

 induced man and his relatives to attempt it and 

 persevere in it successfully? We think that the 

 answer is given in Professor F. Wood Jones* 

 recent brilliant study of " Arboreal Man," and in an 

 earlier not less brilliant study by Dr. R. Anthony, 

 a French zoologist. 



Professor Wood Jones has worked out very con- 

 vincingly the thesis that Man had no quadrupedal 

 ancestry, but that the Primate stock to which he be- 

 longs was, from the first, bipedal and arboreal, and 

 that the leading peculiarities of man and his distant 

 relatives w r ere wrought out during a long arboreal 

 apprenticeship. When we say " from the first " we 

 mean from the time when the Primate race diverged 

 from a stock of generalized placental mammals, or 

 from a stock of bipedal arboreal reptiles, represented 

 perhaps by some of the extinct Therapsids. It is 

 interesting to remember the view of some experts 

 that birds were also evolved from an ancient stock 

 of arboreal reptiles. All these pedigrees are hidden 

 in the mist, but this need not hinder a discussion 

 of the organic lessons that may have been learned 

 in the primeval school of the tree-tops. The first 

 great gain of arboreal life on bipedal erect lines 

 (and not in the fashion of sloths, bats, and the like) 

 was the emancipation of the hand. The typical 

 quadruped needs its fore limb as a stable supporting 

 pillar and organ of progression upon the earth, but 



