Correlation and Application of Statistics to Problems of Heredity 59 



various degrees (pp. 1-2). Such are the three fundamentally novel problems 

 which Galton set himself in Natural Inheritance; we shall endeavour to 

 show the extent to which he has solved them, or at least has suggested 

 methods of solving them, in the following discussion of that work. 



Chapters II and III are general in character, expressing Galton's own 

 views on heredity, and erring, if at all, in rather too much appeal to analogy. 

 In the first of these chapters Galton states his opinion as to "natural" and 

 " acquired " characters, indicating that he considers the inheritance of the 

 latter extremely doubtful ; he emphasises the importance of closely criticising 

 the evidence offered in each case to prove the transmission of acquired 

 faculties, citing especially the possibilities of intra-uterine influence*. He 

 refers to the difficulty of combining male and female measures, and states 

 that: 



"Fortunately we are able to evade it altogether by using an artifice at the outset, else, looking 

 back as I now can, from, the stage which the reader will reach when he finishes this book, I hardly 

 know how we should have succeeded in making a fair start. The artifice is never to deal with 

 female measures as they are observed, but always to employ their male equivalents in place of 

 them. I transmute all the observations of females before taking them in hand, and thenceforward 

 am able to deal with them on equal terms with the observed male values." (p. 6.) 



Galton for stature multiplied every female stature by 1"08 to reach its 

 male equivalent, or added about one inch to every foot of female stature. He 

 does not tell us how he demonstrated that equivalence, whether from the 

 ratio of the mean values in men and women, or more adequately by finding 

 it held (approximately) for all grades f. The true method is to reduce each 

 deviation from the mean by dividing by its standard deviation, or other 

 measure of variability, and it was an inspiration on Galton's part that led 

 him to recognise that at any rate for the case of stature, the ratio of vari- 

 abilities in male and female was close to the ratio of their mean values. See 

 our p. 15 above. 



On p. 7 Galton deals with what he terms Particulate Inheritance. He 

 recognises that an individual may possess characters, which are known 

 to have existed in an ancestor, but were not in the immediate parents. 

 From this idea of latent characteristics Galton reaches the conception of 

 inheritance in the individual as a "mosaic" of ancestral factors, and illustrates 

 his views by two analogies, that of a builder's yard, with fragments of old 

 buildings ready to be used again (p. 8), and the vegetations on two islands 

 which spread to adjacent islets (pp. 10-12). I think he would have done 

 better to have retained his earlier conception of the "stirp" (see our Vol. II, 



* The complexity of this latter source must be borne in mind, if we can accept Galton's state- 

 ments on pp. 15-16, that not a drop of blood passes from mother to child, and yet that a mother's 

 system maybe "drenched with alcohol and the unborn infant alcoholised" during all its intra- 

 uterine existence. 



f Probably in this latter way ; see his p. 42, where he says we are to transmute female to 

 male measures by comparing their respective "schemes," and devising a formula which will 

 change one to the other. A "scheme," supposed normal, depends on two constants, the mean 

 and the variability. Galton does not point this out, or state the inference which follows from 

 his use of the factor 1 -08. 



8—2 



