G ALTON'S HUXLEY LECTURE 



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very precise.) Mr. Gallon's result is that of the 35 + V youths, 

 six come from + V (fourth) parentages ; ten from -I- U (third) ; 

 ten from +T (second); five from +S (first); three from R, 

 and none from below R. 



But along with this very suggestive result, we have to con- 

 sider the numerical strengths of the contributing parentages. 

 When this is done, " we see that the lower classes make their 

 scores owing to their quantity and not to their quality ; for 

 while 35 -fV-class parents suffice to produce six sons of the 

 -fV-class, it takes 2,500 R-class fathers to produce three 

 of them." Thus from the point of view of eugenics, if we 

 wish to increase the number of -fV-class offspring, the most 

 profitable source is to be found among the more prepotent 

 -I- V- class parents ; they are three times more profitable than 

 those of the next class, +U, and 143 times more profitable 

 than those of class R ! 



Other Facts of Heredity. One is tempted to linger over that 

 mode of inheritance which is called true reversion, where ancestral 

 characters that have lain latent for several generations suddenly 

 find opportunity to reassert themselves. It is true that " rever- 

 sion " has been a convenient " free toom " into which much 

 rubbish has been shot. It is true that reversion has been terribly 

 confused with arrests of development (usually of modificational 

 origin), with the not uncommon variations in those numerous 

 vestigial structures of which our body is a walking museum, 

 with independent variations that " happen to hit an old mark 

 in aiming at a new one " or simply suggest to the credulous a 

 harking-back to a more or less hypothetical ancestral type, and 

 even with the normal and everyday occurrence of filial regression. 

 Yet it is undeniable that ancestral traits may remain long latent, 

 apparently but never really lost, and that, in the intricate 

 shuffling of the cards which is associated with the maturation 

 and fertilisation of the germ-cells, they may suddenly find their 

 appropriate liberating stimulus, and assert themselves once more. 



