NATURE CROWNED IN MAN 557 



of human offspring, would help in the growth of gentleness. 

 The lengthening of the period of gestation would not of 

 itself mean much in the way of racial advance unless we 

 believe that it could as it were repercuss on the germinal 

 organisation. But it would mean much if there was at the 

 same time a germinal variation in the direction of an en- 

 larged brain. Great importance, as we have seen, is to be 

 attached to ' temporal variations ' which consist in altering 

 the ' time ' of different periods in the life-cycle, lengthening 

 out here and shortening down there; and the prolongation 

 of youth, also characteristic of mankind and of many very 

 clever mammals, means, as Dr. Chalmers Mitchell has well 

 shown, giving time for breaking down instincts and replac- 

 ing them by remembered results of experiment, for proving 

 all things, for tentatives in self-expression. It is a significant 

 fact that " Man's brain is only about one-fifth of its adult 

 weight at birth, that of the anthropoid is already two-thirds. 

 . . . By the end of the second year the human brain has 

 reached two-thirds of its adult size, it has then reached the 

 same relative degree of development that the anthropoid has 

 reached at birth ' (Keith, The Human Body, p. 37). 



Consideration must also be given to the possible result of 

 walking erect, of using sticks and stones, of making beds 

 and shelters, of living in families and co-operating socially, 

 of talking a good deal. And all these are illustrated among 

 Primates lower than Man. The Anthropoid Apes are not 

 social creatures, but it must be borne in mind that many 

 of the lower Primates are. There is the raw material of 

 social organisation at many a level among mammals, and 

 there are springs of good conduct, too, which no one need be 

 ashamed to have inherited. 



We are ignorant of the factors in the ascent of Man, 



