Correlation and Application of Statistics to Problems of Heredity 53 



length, though partly for the sake of compactness, it is only those of length that 

 will be here given as examples" (loc. cit. p. 137). Galton already saw clearly 

 that his new method enabled comparison to be made on equal terms between 

 variates with such intrinsic diversity as acuity of vision and head breadth*. 

 I have endeavoured to check Galton's work. I expect he found his 

 medians and quartiles by plotting an "ogive curve" (see our p. 31 and 

 Plate II) and smoothing it. The process of checking is rendered difficult by 

 the following statements on p. 138: 



" It is unnecessary to extend the limits of Table II [that of stature and cubit reproduced 

 above] as it includes every line and column in my MS. table that contains not less than twenty 

 entries. None of the entries lying within the flanking lines and columns of Table II were used." 



The first statement seems to suggest that the whole table has not been 

 printed, the second leaves one in doubt as to how to find the medians of the 

 arrays, or indeed of the marginal totals, if none of the entries in the flanking 

 lines and columns had been used. Unfortunately I have not succeeded in dis- 

 covering the original work and manuscript tables for this memoir among 

 Galton's papersf . Putting aside the possibility of re-examining Galton's own 

 work by more modern methods, we can, I think, indicate how closely his semi- 

 graphic median, quartile and regression slope methods accord with those 

 obtained from much longer series by more accurate processes. First let us 

 consider the correlation coefficients : 



The values in the first column of this table were the first organic corre- 

 lations ever published, and on that account are of great historical interest. 



* It is not without interest to note that more than a quarter of a century later, Major 

 Leonard Darwin could assert that the influences of environment and heredity could not be com- 

 pared, because there was no common unit of measurement applicable to them both ! He 

 appeared still ignorant of Galton's use of Q. See Eugenics Review, Vol. v, p. 152. 



f My colleague, Miss E. M. Elderton, has taken out the first 348 entries for male adults 21 

 years and upwards from Galton's Laboratory records, and the resulting values from her tables, 

 computed by modern methods, are given in brackets in the above and the following tables. 

 Our table for stature and cubit differs somewhat from Galton's but with a probable error of 

 •01 1 3 the correlation is hardly significantly different from Galton's value. Both Knee Height and 

 Cubit are measured in the Anthropometric Laboratory at University College, but the former is 

 measured to the lowest point of the patella with the subject standing at rest, while Galton 

 measured to the top of the knee with the subject sitting. Galton deducted the measured heel, we 

 measure with boots off. Our correlation for male students of Knee Height and Cubit is only 0-66. 





