742 PRIMATES 



through the potency of various kinds of selection acting upon the 

 slight variations which appeared in individuals in obedience to the 

 tendency planted in all living things. These differences manifested 

 themselves externally in the colour of the skin, the colour, quality, 

 and distribution of the hair, the form of the head and features, and 

 the proportions of the limbs, as well as in the general stature. 



Geographical position must have been one of the main elements 

 in determining the formation and permanence of races. Groups of 

 Men isolated from their fellows for long periods, such as those 

 living on small islands, to which their ancestors may have been 

 accidentally drifted, would naturally, in course of time, develop a 

 new type of features, of skull, of complexion, or hair. A slight set 

 in one direction in any of these characters would constantly tend 

 to intensify itself, and so new races would be formed. In the same 

 way different intellectual or moral qualities would be gradually 

 developed or transmitted in different groups of Men. The longer 

 a race thus formed remained isolated the more strongly impressed 

 and the more permanent would its characteristics become, and less 

 liable to be changed or lost when the surrounding circumstances 

 were altered or under a moderate amount of intermixture from 

 other races — the more " true," in fact, would it be. On the other 

 hand, on large continental tracts, where no mountain ranges or 

 other natural barriers form obstacles to free intercourse between 

 tribe and tribe, there would always be a tendency towards uni- 

 formity, from the amalgamation of races brought into close relation 

 by war or by commerce. Smaller or feebler races would be 

 destroyed or absorbed by others impelled by superabundant popu- 

 lation or other causes to spread beyond their original limits ; or 

 sometimes the conquering race would itself disappear by absorption 

 into the conquered. 



Thus for untold ages the history of Man has presented a shift 

 ing kaleidoscopic scene : new races gradually becoming differenti- 

 ated out of the old elements, and, after dwelling a while upon the 

 earth, becoming either suddenly annihilated or gradually merged 

 into new combinations ; a constant destruction and reconstruction ; 

 a constant tendency to separation and differentiation, and a tendency 

 to combine again into a common uniformity — the two tendencies 

 acting against and modifying each other. The history of these 

 processes in former times, except in so far as they may be inferred 

 from the present state of things, is a difficult study, owing to the 

 scarcity of evidence. If we had any approach to a complete 

 palaeontological record, the history of Man could be reconstructed ; 

 but nothing of the kind is forthcoming. Evidence of the anatomi- 

 cal characters of Man as he lived on the earth during the time 

 when the most striking racial characteristics were being developed, 

 during the long ante-historic period in which the Negro, the Mon- 



