On Mendel's Laws. 
1 95 
phenomena only makes me regret the more the defects of his style 
and manner of treatment. The assumed separation of characters 
in the germ cells of the hybrid on which Mendel based his expla¬ 
nation of the results he had observed, may, as Mr. Bateson suggests, 
very possibly be proved in the future to hold good over a much 
wider field than has yet been experimentally tested. Mendel’s 
phenomena may bring us to revise fundamentally some of our 
conceptions of heredity, they may suggest new directions in which 
to seek for solutions of some problems of the cell, they may throw 
fresh light on the process of fertilization in general, and on the 
nature of variation. But it must be remembered that at present 
Mendel’s Laws are only known to hold for cases of hybridisation, 
and do not appear to hold invariably then; in the present state of 
our knowledge it is speculation—legitimate, even desirable, but 
still speculation, pure and simple,—to postulate the existence of 
similar phenomena when breeding only with a pure strain. It is well 
that such a possibility should be borne in mind, and that the whole 
case should be fully and impartially discussed and considered. Yet 
Mr. Bateson has taken the very action most effectually calculated 
to render calm criticism and unbiassed judgment impossible, as he 
may by now have realized. The language of unbridled enthusiasm 
and lavish abuse creates nothing but mistrust. It is most regret¬ 
table that this convenient translation of Mendel’s papers should 
appear in so disadvantageous a context. Many of the conclusions 
at which Mr. Bateson arrives seem so entirely due to his misunder¬ 
standings of various passages in the writings of Mr. Galton and 
Professor Pearson that I propose, in the first place, to deal not 
with Mendel’s work at all, but with that of the statistical or 
biometrical school. Having cleared the ground in that direction, 
it will be easier to institute comparisons between the results 
obtained by the two schools, and to discuss the bearing of the two 
classes of observations on each other. 
There has always been a good deal of misunderstanding between 
biologists in general and those who have done pioneer work in the 
use of statistical methods, due in great part, I believe, to the fact 
that the two do not use such terms as heredity, variation, variable, 
variability, in precisely the same signification. The employment of 
quantitative methods necessarily leads to the use of such expres¬ 
sions in a more precise signification, and hence to a greater or less 
amount of divergence from the older and more popular usage. 
“Heredity” is, for instance, most usually defined by biologists as 
