236 THE EEGULATION OF NUMBEES 



calculated to live to an advanced age '.^ Du Pratz speaks highly 

 of the physical characteristics of the Natchez and much similar 

 evidence could be quoted. ^ Azara, for instance, says that the 

 Payaguas hved to an advanced age ^ and also mentions especially 

 the fine physical features of the Mbayas ^ and of the Charruas.^ 

 Of the Mandrucos Wallace says that ' their figures are generally 

 superb ; and I have never felt so much pleasure in gazing at the 

 finest statue, as at the living illustrations of the beauty of the 

 human form. The development of the chest is such as I believe 

 never exists in the best formed Europeans, exliibiting a splendid 

 series of convex undulations, without a hollow in any part of 

 it.' ^ Humboldt remarks of the Chaymas that both men and 

 women ' are very muscular, but fleshy and plump '? So, too, 

 Spix and Martins, speaking of Brazilian tribes, say that ' the 

 Indians are seldom sick and generally live to an advanced age '.^ 



Lastly it may be observed as evidence of some weight that, as 

 between different races, the higher the skill and the greater the 

 natural richness of the surroundings, the higher, so far as we can 

 judge, is the return per head. Though the return cannot be 

 measured, all that we know of the conditions of life point to this 

 conclusion, whether we contrast the agricultural races in general 

 with the hunting and fishing races, or whether we contrast such 

 hunting and fishing races as those of the north-west coast of 

 America with the Fuegians. 



12. The conclusions derived from a study of the first two 

 groups are therefore to the effect that an approximation to the 

 desirable number is normally attained by the practice of one or 

 more of the three customs mentioned. As a result, the small 

 average size of the family is arrived at — the size being just about 

 that which allows for the average mortality from various causes 

 later in life, so that in the next generation there will be as nearly 

 as possible the same number of adults as in the former generation. 

 It may be that, as an occasional coincidence, just that amount 

 of reduction of fertihty and just that amount of ehmination 

 necessary to bring about approximation are effected by means of 

 those factors which were described as having incidentally these 

 results. But such a coincidence must be very rare and the 



1 Heriot, loc. cit., p. 350. ^ Du Pratz, vol. ii, p. 161. * Azara, 



loc. cit., vol. ii, p. 142. ' Ibid., p. 107. ^ Ibid., p. 8. « Wallace, 



Narrative, p. 478. ' Humboldt, Personal Narrative, vol. iii, p. 233. * Spix 

 and Martius, loc. cit., vol. ii, p. 249. 



