" ARBOREAL MAN " 217 



two different appetites : one refined and temperate, and the 

 other comparatively coarse and indiscriminate. 



Whilst engaged in giving the lie to the teaching of modern 

 orthodox anatomy and anthropology that man had evolved from 

 a quadrupedal pronograde mammalian stage, the author tells 

 us that it was the arboreal habit which saved the particular 

 Mammalian stock which culminated in Man from becoming four- 

 footed pronogrades. For the details of this teaching I must refer 

 the reader to the book itself. In endeavouring to draw a picture 

 of his hypothetical primitive Mammal, taking, not to a terrestrial 

 but to an arboreal life, the author offers, however, the following 

 interesting remarks : 



The ability which such a primitive Mammal would have for climbing 

 might perhaps be gauged by having regard for that skill in clambering 

 which is manifested in the tailed Amphibians, a skill which we must 

 remember develops within the limits of their own Phylum (in the Tree 

 Frogs) into perhaps the most perfected tree-climbing displayed in the 

 Vertebrate series. It may seem a long way to go back when attempting 

 to unravel the influences of tree-climbing among the Primates, to appeal 

 to the clambering activities of the water-newt. And yet the anatomical 

 condition of the limbs of Man demands a shifting backward of the inquiry 

 to some such stage as this. I believe that the truest picture of the evolu- 

 tion of Primate climbing starts with such a scene as we are depicting now. 

 The method of this amphibian or reptilian clambering must be appreciated, 

 for, as we shall see, climbing may be conducted in several different ways ; 

 and the particular method practised by any animal may serve to date the 

 evolutionary stage at which the habit was adopted. An Amphibian, or 

 unspecialised Reptile, ascends an obstacle by clambering up ; its feet 

 are applied to the surface of the obstacle up which it clambers. It makes 

 no attempt to obtain a grip by nails or claws, but it trusts merely to the 

 apposition of its feet to the surface to which it clings, and when this fails 

 the animal falls. 



Two points must be especially noticed. As its progress continues, 

 it repeatedly reaches ahead with one or other of its fore-limbs for a new 

 hold, and whilst doing this its body weight is temporarily thrown upon its 

 hind-limbs. And, again, in reaching out its fore-limb, the freedom of 

 rotation possessed by the second segment of the limb allows the animal 

 to apply the palmar surface of its " hand " against any new hold which 

 may present itself at almost any angle. 



From such a humble beginning great developments are possible ; and 

 here we may observe that, without the apprenticeship served in this lowly 

 clambering, short cuts to tree-climbing have never attained the same 

 ultimate perfection. As arboreal life becomes more complete, the search 

 for a new foot-hold will become a far more exacting business than it is in 

 the mere clambering we have pictured. The more exacting this search 

 becomes, the more will there tend to be developed that most important 



