328 STATISTICAL STUDY OF INHERITANCE 



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. Criticisms of Galton's Law 



Since the importance of the law is great, we must devote 

 some attention to certain criticisms which have been made. 

 It goes without saying that those who wish to criticise the basis 

 on which the generalisation is founded must consult the original 

 documents, referred to in the bibliography. 



It must be borne in mind that the Law of Ancestral Inheritance 

 is a statistical conclusion dealing with what is true on an average 

 for a large number of cases. To say that we know of particular 

 cases where it does not hold — where, for instance, the amount of 

 resemblance between an individual and his paternal grandfather 

 is far greater than is represented by the theoretical fraction 

 — is no argument against the induction. It is like saying that 

 the statistics showing the percentage of deaths in cases of scarlet 

 fever must be wrong because we know of large families which 

 were visited by the disease without a single fatal result ! 



It may be urged against the crispness of Galton's Law, (1) that 

 the hereditary relation is a complex affair ; (2) that most or- 

 ganic qualities, and the amounts of resemblance in successive 



