80 
PROFESSOR K. PEARSON AND DR, A. LEE ON 
NOTE. 
This memoir was originally presented to the Society on August 5, 1899, and read on November 16, 
1899. In working out by the same theory the coefficients of inheritance for Basset Hounds, Mr. Leslie 
Bramley-Moore discovered that the method adopted was not exact enough in its process of propor¬ 
tioning. Accordingly, with the assistance of Mr. L. N. G. Filon, we immensely developed the theory, so 
that it was necessary to rewrite the theoretical part of the original memoir. This has been carried out in 
Part VII. of this series. The present memoir consists substantially of the portions of the original 
memoir relating to the inheritance of coat-colour in Horses and eye-colour in Man, with the numerical 
details and the resulting conclusions modified, so far as the extended theory rendered this necessary. In 
the very laborious work of reconstructing my original tables I have received the greatest possible assistance 
from Dr. Alice Lee, and I now wish to associate her name with mine on the memoir.* The memoir 
was at my request returned to me for revision after it had been accepted for the ‘ Philosophical 
Transactions.’ 
Part I.—Introductory. 
(1.) A certain number of characters in living forms are capable of easy observation, 
and thus are in themselves suitable for observation, but they do not admit of an 
exact quantitative measurement, or only admit of this with very great labour. The 
object of the present paper is to illustrate a method by which the correlation of such 
characters may be effectively dealt with in a considerable number of cases. The con¬ 
ditions requisite are the following :— 
(i.) The characters should admit of a quantitative order, although it may be 
impossible to give a numerical value to the character in any individual. 
Thus it is impossible at present to give a quantitative value to a brown, a bay, or a 
roan horse, but it is not impossible to put them in order of relative darkness of shade. 
Or, again, we see that a blue eye is lighter than a hazel one, although we cannot 
a priori determine their relative positions numerically on a quantitative scale. 
Even in the markings on the wings of butterflies or moths, where it might be 
indefinitely laborious to count the scales, some half dozen or dozen specimens may 
be taken to fix a quantitative order, and all other specimens may be grouped by 
inspection in the intervals so determined. 
We can even go a stage further and group men or beasts into simply two 
categories—light and dark, tall and short, dolichocephalic and brachycephalic — and 
so we might ascertain by the method adopted whether there is, for example, correla¬ 
tion between complexion and stature, or stature and cephalic index. 
(ii.) We assume that the characters are a function of some variable, which, if we 
* I have further to thank Mr. Leslie Bramley-Moore, Mr. L. N. G. Filon, M.A., Mr. W. R. 
Macdoneli., M.A., LL.D. and Miss C. D. Fawcett, B.Sc., for much help in the arithmetic, often for 
laborious calculations by processes and on tables, which were none the less of service if they were 
afterwards discarded for others. To Mr. Bramley-Moore 1 owe the extraction and part of the 
arithmetical reduction of the horse-colour tables. 
