SUBORDER c BIMANA 283 



the apes, particularly to the Simiidae (Anthropomorphs) ; hence it is difficult 

 to draw sharp anatomical distinctions between them. According to Huxley, 

 the differences between the highest and lowest apes are far more marked 

 than those separating Man and the anthropoid apes. The highly arched form 

 of the very spacious skull-cap, the considerable preponderance of the cranial 

 over the facial region, and the absence of a sagittal crest very clearly 

 distinguish the head of Man from that of all higher apes, yet in these 

 respects many South American forms approach very closely to Man. In 

 size and weight the human brain very much surpasses that of all apes, but 

 in anatomical structure, in the development of the cerebrum and the 

 complexity of the convolutions, the same general plan prevails in apes and in 

 Man. The fusion of the premaxillary with the maxillary, and the absence 

 of a diastema, together with the relatively weak canine teeth, are unimportant 

 characters. Compared with the produced muzzle (prognathous) of most 

 apes, the face of man is abruptly sloping (orthognathous). With this facial 

 structure is associated the almost vertical symphysial region of the mandible 

 and a somewhat prominent bony chin. 



In form, the lower jaw is horse-shoe shaped, and the two anchylosed 

 rami enclose a much broader space for the tongue than in any apes. In the 

 number and form of the teeth, the dentition agrees with that of the Old 

 World apes ; the canines, however, scarcely project beyond the continuous 

 dental series, and the tubercles of the cheek teeth are more obtuse, broader 

 and lower than in the apes. As a rule, the superior and inferior molars 

 are quadritubercular. On the superior molars, however, the hypocone 

 remains inferior in size to the protocone and is sometimes suppressed, in 

 which case a tritubercular tooth results. In the inferior molars, the four 

 principal cusps are frequently accompanied by a single conule on the posterior 

 border. The single-rooted premolars are less complex and shorter than the 

 molar teeth, and consist of an external and internal tubercle. In Australians, 

 New Caledonians and negroes, a fourth molar sometimes appears, as in 

 the orang, while in civilised races there is a noticeable tendency toward 

 the suppression of the last molar (wisdom tooth). The double sigmoid curve 

 in the spinal column, the considerable length and strong musculature of the 

 limbs, the breadth of the shoulders and the proportionately short length of the 

 arms are correlated with the upright gait. In mobility and capacity for 

 adaptation, the human hand far surpasses the hand of apes. The thumb is 

 strongly developed, opposable and very movable. The sole of the foot is 

 horizontal. The metatarsals and tarsals form an arch, and the stout non- 

 opposable hallux cannot be used in grasping, but merely aids in supporting 

 the weight of the body. 



Numerous authentic remains of fossil Man occur in the Pleistocene, 

 where domestic animals are wanting, and where a number of extinct species 

 are intermingled with forms similar to those of the existing fauna and flora. 

 In Europe the human dwelling-places in caves, rock-shelters and river settle- 

 ments belong chiefly to the so-called " Reindeer Period," for the most part of 

 glacial or post-glacial age. Metal implements and clay vessels are unknown. 

 Flint, bone, horn and ivory were chiefly used for weapons, implements and 

 ornaments. 



The flint implements of the palaeolithic or older Stone Age are dis- 

 tinguished from those of the neolithic by the lack of intelligent handiwork. 



