Contribution of each Ancestor to the Heritage of Offspring. 401 



than tbe left. The difference between the means of the two sides 

 would appear to vary in different races ; also it is distinctly greater in 

 woman than in man. 



(1L) The absolute correlation between the lengths of the long 

 bones is high, while, on the other hand, the correlation between 

 length and breadth would appear to be w^eak. 



(12) On comparing w r ith the Aino it would seem that serially 

 homologous bones are more strongly correlated with one another than 

 are non-homologous bones. Also the femur and tibia are more 

 closely correlated than the humerus and radius. Distal bones would 

 appear to be somew r hat less correlated with one another than are 

 proximal bones, e.g., there is slightly less correlation between the 

 tibia and radius than between the femur and humerus. 



In the New Race woman was distinctly less correlated than man. 



(13) Sometimes it is desirable to refer the variations to some 

 standard, such as stature. The index-correlations tend to be lower 

 than the absolute correlations. From the results v, r o have obtained 

 it appears doubtful as to what meaning we can attach to the dif- 

 ference between the observed correlation of ratios and Professor 

 Pearson's " spurious correlation." 



(14) The New Race approached the Negro in the proportional 

 lengths of the limb-bones to one another, but the sacral and scapular 

 indices were nearly identical with those of Europeans. 



" The average Contribution of each several Ancestor to the 

 total Heritage of the Offspring." By Francis G ALTON, 

 D.C.L., Sc.D., F.R.S. Received and Read June 3, 1897. 



In the following memoir the truth will be verified in a particular 

 instance, of a statistical law of heredity that appears to be universally 

 applicable to bisexual descent. I stated it briefly and with hesitation 

 in my book 'Natural Inheritance' (Macmillan, 1889; page 134), 

 because it was then unsupported by sufficient evidence. Its exist- 

 ence was originally suggested by general considerations, and it might, 

 as will be shown, have been inferred from them with considerable 

 assurance. Consequently, as it is now found to hold good in a' 

 special case, there are strong grounds for believing it to be a general 

 law of heredity. 



I have had great difficulty in obtaining a sufficient amount of 

 suitable evidence for the purpose of verification. A somewhat exten- 

 sive series of experiments with moths were carried on, in order 

 to supply it, but they unfortunately failed, partly owing to the 

 diminishing fertility of successive broods and partly to the large 

 disturbing effects of differences in food and environment on different 



