NURTURE AND NATURE I5 



(3) That there is a distinct difference in the 

 correlation coefficients in the different school groups 

 in Glasgow. This is not what we should expect 

 if the population were homogeneous, and leads one 

 to think that some special influence must be at 

 work which has lowered the correlation in the worst 

 school group or raised it in the better school groups. 

 Taking into consideration the value found for the 

 Edinburgh schools I should be inclined to think that 

 the factor we have not yet measured is one that has 

 artificially raised the coefficient in the better school 

 groups. 



We must next compare the influence of the 

 employment of the mother on the physique of her 

 son with the hereditary influence of the actual height 

 of the mother on the height of her son. This 

 hereditary influence is given in Table I for the sake 

 of comparison. The effect of inheritance of stature 

 of mother and son is measured by the coefficient '49. 

 The coefficients for eye-colour for the parental, 

 grand parental, and great grand parental relation- 

 ships are also given, and it will be noticed that the 

 only value at all comparable with the environmental 

 values is that found for great grand parents, which 

 is about equal to that found for the effect of mothers* 

 employment on sons' height in Glasgow, but distinctly 

 higher than the other correlation coefficients. We 

 cannot help being struck by the comparative unim- 

 portance of, at any rate, one environmental factor as 

 compared with the heredity factor. 



I will add one further remark on the differences we 

 have found in the correlations between employment 



