376 HISTORICAL GEOLOGY 



low the surface. In this case, as well as that of Pithecanthropus, 

 the depth of over-lying materials and the close associations of the 

 remains of other Mammals, including certain now extinct species 

 (e.g. Rhinoceros etruscus), pretty clearly point to an age not later 

 than about the early Pleistocene. 



Summarizing the characteristics of the forms represented by 

 these two specimens (Pithecanthropus erectus and Homo heidel- 

 bergensis), Duckworth says: " Evidence exists in each case to the 

 effect that far-distant human ancestors are hereby revealed to 

 their modern representatives. Of their physical characters, dis- 

 tinct indications are given of the possession of a small brain in a 

 flattened brain-case (see Fig. 234) associated with powerful jaws 



a b c 



Fig. 234 

 Comparison of skulls: a, modern Chimpanzee; b, Paleolithic Man; 

 c, modern Frenchman. (After E. Rivet, from New York State 

 Museum Bulletin 173.) 



and massive continuous brow-ridges; the lower part of the face 

 being distinguished by the absence of any projection of the chin. 

 The teeth indicate with some degree of probability that their diet 

 was of a mixed nature, resembling in this respect the condition of 

 many modern savage tribes. . . . Whether they habitually as- 

 sumed the distinctive erect attitude is a point still in doubt. . . . 

 It is probable that in stature they were comparable, if not superior 

 to, the average man of today. " x It seems clear, therefore, that 

 these remains represent a type intermediate between Men and the 

 more highly developed Apes. 



Paleolithic Men. — Many examples of the bones and imple- 

 ments of Pleistocene Men have been found in Europe, principally 

 in caves within and without the glaciated area. It is very difficult, 

 if not impossible, in any case to determine the precise glacial or 

 1 W. H. L. Duckworth: Prehistoric Man, pp. 60-61. 



