1 8 THE EVOLUTION OF MAN 



gorilla. Within the jaw at the symphysis there is the genial 

 pit for the attachment of the tongue muscles as in the anthro- 

 poids, and, like them, the bone encroaches on the floor of the 

 mouth. In both these respects the jaw is more simian than 

 human but not sufficiently so to preclude the possibility of rudi- 

 mentary speech. The body of the jaw is not unlike that of 

 the successor of Heidelberg man, the Neandertal race, but the 

 ascending branch which gave attachment for the masticating 

 muscles differs in shape, being gibbon-like, and is much greater, 

 as great in fact as that of a female orang. The teeth, while 

 actually large, are relatively small, and the taurodontism is 

 developed in a marked degree, as shown by the enlarged pulp 

 cavity, dilated crowns, and abbreviated roots. The teeth are 

 regularly placed and the canines are not in any way bestial in 

 their development, less so, indeed, than in some modern men. 

 Without the teeth, the Heidelberg jaw might well be con- 

 sidered as that of an ape, but the teeth affirm its human affini- 

 ties although in their development and in the form of the 

 dental arch they are prophetic of Neandertal, not of modern, 

 man. Keith does not believe that either Heidelberg or Nean- 

 derthal man lies in the direct line of modern descent, but that 

 the taurodont dentition implies a specialization for a rough 

 herbivorous diet and that in this respect both races show a 

 departure from the more simian dentition and implied feeding 

 habits of the main line of descent into Homo sapiens. 



While the skull of Heidelberg man is yet unknown, Doctor 

 McGregor has nevertheless attempted its reconstruction, for 

 of course many dimensions, as well as the character of the 

 upper teeth, can be learned from the lower jaw, while the re- 

 mainder of the skull was studied from its Neandertal succes- 

 sor. The result is a pre-Neandertal skull, elongated, with a 

 low forehead, prominent brow-ridges, and a rounded dental 

 arch, and there is reason to believe that this reconstruction will 

 prove prophetic when the actual cranium is revealed to us by 



