128 



Miss M. A. Whiteley and Prof. Karl Pearson. 



with a vernier, so that the readings conld be nominally made to 

 1/100 inch. Both the hands of 551 women were measured. At first it 

 was proposed to include only those of more than 20 years of age, but 

 no sensible difference was found for the means of those between 18 

 and 20, and accordingly some sixty or more between these years 

 were included in the final results. While more than a moiety of the 

 measurements and nearly all the laborious arithmetical reductions were 

 made by one of us, Miss M. A. Whiteley, we owe measurements on 

 the students of University, Girton, Newnham, and Westfield Colleges 

 to the energetic assistance of Miss Dorothy Marshall, B.Sc, and a 

 further ninety sets, principally from the students of Bedford College, 

 to Miss Edith Humphrey, B.Sc, to both of whom we wish to acknow- 

 ledge our great indebtedness. 



In the tabulation of results the grouping was done to 1/20 inch, and 

 the means, standard deviations, coefficients of variation, and coefficients 

 of correlation, together with their probable errors, calculated by the 

 processes and formulae already fully described in papers of the series 

 " Mathematical Contributions to the Theory of Evolution," by one of 

 the present writers. Pianists were specially noted on the data cards, 

 but their numbers did not seem sufficiently large to justify any con- 

 clusions as to the effect of use on variability and correlation — a subject 

 which deserves very careful and special investigation.* 



The following notation is used : — 



Ei = 



first joint of right-hand index finger. 



Eii = 



„ „ middle „ 



Eiii = 



ring 



Eiv = 



„ „ little „ 



Li = 



„ left-hand index „ 



Lii = 



„ „ middle „ 



Liii = 



ring 



Liv = 



little 



3. Relative Size of the Hands. — Turning first to the absolute dimen- * 

 sions of these joints we have, the measurements being in inches : — 



Table I. — Lengths of First Joints of Fingers. 



R. L. 



i. 2-2482 ± 0-0030 2*2252 ± 0*0031 



ii. 2-3879 ± 0-0033 2*3667 ± 0-0033 



iii. 2-2108 ± 0-0031 2-1878 ± 0*0031 



iv. 1-8427 ± 0-0028 1-8197 ± 0-0028 



* What effect ma; particular trades or forms of exercise have in modifying the 

 variability of the limbs used and their correlation to other limbs ? The relative 

 importance of use and of selection in determining the current values of variability 

 and correlation will one day require very careful investigation. 



