178 A. D. Darbishire. 
of the corollary, which follows from the demonstration that the 
character of offspring are not determined by their remoter ancestors, 
that the somatic characters of the parents themselves play no part 
in determining the character of their progeny. 
Let us return to the fact that Mendel did not publish the 
proportions in which greens segregated out, in any generation below 
F 2 . Taken in conjunction with the fundamental difference between 
Mendel’s and Nageli’s points of view, this fact is of deep interest. 
It simply shows that Mendel had no preconceived ideas with regard 
to that which strikes those of us who have not been fed on 
Mendelian pap from our intellectual youth up, as the most remarkable 
thing about what follows from the Mendelian theory (and does 
actually occur for six generations), namely, the phenomenon of the 
production by the hybrids (bearing the dominant character) in every 
generation, of individuals bearing the recessive character, in 
proportions which do not diminish as we proceed further from the 
original cross. It does not strike me as a very wonderful thing that 
an Hybrid should produce 25 % greens, but it does strike me as a 
wonderful thing that an F 10 Hybrid will do precisely the same 
thing. Yet it is just those generations about which we who are just 
freeing ourselves from a belief in ancestral contributions are most 
anxious to know, about which Mendel gives us least information. 
This would certainly seem to indicate that Mendel approached his 
subject unprejudiced by the theory of ancestral contribution in any 
form. And if this is true it helps to explain how it was that Mendel 
came to attack the problem in the right quarter by directing his 
attention exclusively to the contents of the germ-cells, and 
incidentally how it was that Nageli entirely failed to appreciate 
Mendel’s point of view. 
Nevertheless, although 1 have grown out of expecting the 
proportions in which recessives will be produced by hybrids are 
bound sooner or later, in the course of generations, to diminish, I 
feel that it is very important to dwell on the distinction between 
being certain on a priori grounds that the proportion of recessives 
in F 10 hybrid families will be the same as in F 2 , and a posteriori 
knowledge that this is the case. The F 8 generation from the cross 
made by Mr. Hurst in 1902 I hope to record this autumn—the 
plants are in flower now—so that I hope to be able to place on 
record the composition of generations F 2 to F 10 inclusive, during 
the winter of 1911. 
I have laid this stress on the manner in which the Mendelian 
