vin THE HUMAN" EACES 369 



which precipitates that of anthropoid apes, as well as that of man. 

 Another proof that the chemical and physiological constitution of 

 anthropomorphous apes is fundamentally the same as that of man 

 is afforded by the fact that certain diseases, such as syphilis, which 

 were formerly supposed to be peculiar to man can be experi- 

 mentally transmitted to these animals. 



This does not, however, alter the fact of the existence of great 

 and far-reaching differences between man as we know him and the 

 anthropoid ape of the present day. Apart from the undeniable 

 psychological differences which place man on a level so far above 

 the rest of the living world, there are morphological differences 

 characteristic of the human race. These are: the shape and 

 capacity of the skull, the shape and weight of the brain, which 

 are rightly considered of the greatest importance ; the formation of 

 a chin ; the existence of an external nose ; the redness of the lips ; 

 the characteristic distribution of the hair in the adult ; the erect 

 position and the differentiation of the function of the upper 

 limbs, the hands, as the organs of touch and grasp, and of the feet 

 as those of support in the erect attitude. Anthropomorphous apes 

 use both upper and lower limbs for climbing trees. Eecent 

 palaeontological research has, however, shown man's erect attitude 

 to be no recent acquisition, since it characterised various Saurians 

 of the secondary age now extinct ; apart from birds, the shape of 

 whose skeleton differs too widely from that of man, the kangaroo 

 and the bear are the only living animals who can adopt this 

 position, and they only do so exceptionally. 



Viewing these premisses, it is obvious that man must be de- 

 scended from animal forms resembling the anthropomorphous apes 

 of the present day ; this does not, however, involve the hypothesis 

 that these anthropoids represent ancestors of the human race who 

 have happened to survive. On the contrary, it is far more prob- 

 able that these animals and man are alike descended from some 

 common ancestor, collateral branches of the same genealogical tree. 



Klaatsch considers that at the beginning of the tertiary age 

 a large number of lower mammals, with limbs and jaws possessing 

 some of the characteristics of the apes of our own day, inhabited 

 the then existing continents, a theory which is borne out by the 

 researches of palaeontology and comparative anatomy. These 

 mammals may be called primatoids, i.e. the original group from 

 which were derived the various forms which gradually became 

 differentiated in order to compose the three great groups of 

 ape, anthropoid, and man. We may assume with Klaatsch that 

 the common precursor of these three groups was a being who 

 walked in a semi-upright position, but who usually climbed 

 trees, whose trunk and limbs were of medium proportions, that is, 

 whose arms and legs were of much the same length, whose feet 

 and hands were suited to grasping things, whose skull was fairly 



VOL. v 2 B I: 



