240 THE EEGULATION OF NUMBERS 



men were not recognized. There can be no direct proof of this ; 

 but the fact that, wherever we look, absolutely without exception 

 we find among all primitive races the recognition and careful 

 maintenance of such areas, just as much among hunting and 

 fishing as among agricultural races, must lead us to suppose that 

 among the more bkilled hunters of pre-history similar conditions 

 normally obtained. It is altogether unreasonable and without 

 foundation to suppose that the recognition of areas is a develop- 

 ment subsequent to the separation of primitive races from the 

 main line of social evolution. If then the recognition of areas, 

 which probably arose with the development of social organization, 

 was a characteristic of the later prehistoric races, we are led to 

 conclude that the desirability of attaining to and maintaining 

 the optimum number must have had the same consequences as 

 among primitive races. It must, in other words, have resulted 

 in the practice of infanticide, of abortion, or of abstention from 

 intercourse. For there is no reason to assume that the factors 

 bearing upon fertility and ehmination reached a considerably 

 greater intensity than among primitive races. We have, how- 

 ever, no reason to assume that any one of these habits was 

 practised rather than another, for there is, as we have seen, no 

 correlation between these factors and stages in economic develop- 

 ment. All that we assume is that in one way or another adjust- 

 ment was brought about, and in corroboration of this we may 

 note, as will be pointed out in the next chapter, that as pre- 

 historic races emerge into the hght of history there is abundant 

 evidence of the practice by them of one or other of these customs. 

 14. Lastly we may ask how we are to view the change from 

 the conditions under which the pre-human ancestor must have 

 lived to the conditions which we have found reason to attribute 

 to prehistoric races. The conditions to which species in a state 

 of nature are subjected, and to which therefore we assume the 

 pre-human ancestor to have been subject, were described in the 

 second chapter. We found that the fecundity of any species 

 was connected with the sum of all the unavoidable dangers as we 

 called them to which the young of the species are exposed. 

 A limit is set to the development of the strength of fecundity 

 beyond a certain point by the fact that it cannot be to the 

 advantage of any species that its fecundity should increase 

 considerably beyond the point which ensures the survival of the 



