LAW OF ANCESTRAL LNHERLTANCE 329 



Prof. Weldon (1902) states the law of ancestral inheritance in 

 the following terms : " The degree to which a parental character 

 affects offspring depends not only upon its development in the 

 individual parent, hut on its degree of development in the ancestors 

 of that parent." Mr. Yule suggests that, instead of the word 

 " affects," which to some extent implies a direct physical in- 

 fluence, it would be more accurate to read " serves as a basis 

 for estimating the character of." 



In a later paper Prof. Weldon discussed the validity of Galton's 

 Law, and wrote as follows . — 



. . . "The results so far achieved make it probable that Mr. 

 Galton's original prediction will be verified for the large class of 

 cases to which he intended it to apply, and that the influence 

 of the different generations of ancestors, as measured by the 

 regression coefficients between these and existing individuals, 

 will be found to diminish with the remoteness of the ancestors, 

 according to the terms of a simple geometric series, which is 

 sensibly the same at least for all those characters among the 

 higher animals which have been properly examined" (Weldon, 

 1906, p. 108). 



§ 6. Illustration of Results reached hy Statistical Study 



While we can neither explain the methods nor summarise the 

 arguments, it may be permissible to cite some of the results 

 reached by the statistical study of inheritance, always bearing 

 in mind the caution that the validity of a statistical result 

 depends on the value of the data. The world of organisms is 

 very large and heterogeneous, and results that hold good for 

 certain forms of life may not be true of others. 



It has been shown statistically that in the human race the 

 father is prepotent in the matter of stature, and this for offspring 

 of both sexes (Pearson). 



It has been shown statistically that a subtle quality like 



