575.2 115 
es 
On the Scientific Measure of Variability 
‘NO review the reviewer is always a profitless task, and yet I 
am tempted to repeat what must be more or less of a failure. 
In this case, however, the reviewer happens to be a man whose 
opinion deservedly carries weight, and many readers may consider 
that he must have fairly epitomised the statements made in my 
paper on “ Variation in Man and Woman.” This does not seem to 
me to be the case; and, in justice to myself, I wish to distinctly 
repudiate one or two opinions Professor Weldon fastens upon me 
(Natural Science, vol. xi., pp. 50-54), 
In the first place, Professor Weldon states that the object of 
my paper “is to support the contention that women are, on the 
whole, more variable than men.” I wish to entirely disclaim any 
such object. The paper was written with the purely scientific 
aim of comparing the variation of man and woman, and was due 
to the fact that a study of numerous writers on the subject had led 
me to believe that there was as yet no evidence to show greater 
variation in one sex than the other; that most of the reasoning on 
the subject was invalid and nearly all partizan. I may safely say 
that the two friends who undertook with me the lengthy arithmetic 
involved had no “contention” and no bias. We simply thought 
that no evidence of a satisfactory kind was _ forthcoming, 
in the case of man, for Darwin’s law of the greater variability 
of the male; and we determined, so far as was possible, to 
undertake a thorough investigation of the question. And what is 
the general conclusion reached? That the female is more variable 
than the male—which is the impression any reader must form 
from Professor Weldon’s review? Not at all. In the summary 
I distinctly state that, in the material considered, there is no 
evidence of greater male variability, but rather of a slightly 
greater female variability. In the body of the paper it is stated 
that the less civilised races have nearly equal variability for the 
two sexes, while, in the more highly civilised, woman—probably 
owing to the lessening of her struggle for existence as compared 
with man—has apparently greater variability. I conclude :—“I 
would ask the reader to note that I do not proclaim the equal 
variability of the sexes, but merely assert that the present results 
show that the greater variability often claimed for man remains as 
