A CHAPTER OF CONCLUSIONS 501 
Reck, if substantiated, points to the differentiation and 
existence of a pure negro type in the Pleistocene period. 
We know nothing of the fossil remains of the Monc^olian 
RECENT 
PLEISTOCENE 
4,000 ft 
"100,000 years 
PLIOCENE 
5pOO ft 
500,000 years 
MIOCENE 
9,000 f ^ 
900,000 years 
wmmFm 
O LOO WAY 
NEANDERTHAL 
GALLEY HILL 
HEIDELBERG 
EOAN THROPUS 
Pi THECAN THROPUS 
HUMANOID 
STEM 
Fig. 187. — Genealogical tree of man's ancestry. The depth of the deposits and 
the duration of the geological periods are based on estimates published by 
Professor Sollas. 
