A. D. Darbishire. 
172 
the stable, pure-breeding, type with which the cross was made, and 
we might expect that when the green reappears it will breed true : 
and we find that it does. But when we look at the yellows in the 
ancestry of F 2 , we find that there are two types, the pure-breeding 
stable type with which the cross was made, and the unstable type* 
which produces both yellows and greens, which composes F^ So 
that we have three possibilities before us with regard to the yellows 
in F 2 ; they may be all stable or pure-breeding, they may be all 
unstable or hybrid, or some of them may be stable and some 
unstable. Mendel found that the last case obtained; and, moreover, 
determined the proportion in which the two types occurred amongst 
the yellows ; he found that amongst every three yellows in F 2 two 
were, on the average, unstable and one was stable. He also found 
that the composition of the generation produced by F 2 Hybrid 
Yellows was the same as that produced by the Fj Hybrids. 
So that we are now in a position to exhibit the Mendelian 
phenomenon in the following diagram. 
Y x G 
(Hybr.)Y F, 
1 (pure) Y 2 (Hybr.) Y 1 G F 2 
(pure) Y only 1 (pure) Y 2 (Hybr.) Y 1 G G only F 3 
Before we proceed with our argument it may be interesting to 
pause for a moment and see how it was that Goss missed what 
Mendel saw. The cause is not far to seek. Goss was not interested 
in the interpretation of the phenomena before him. The first sen¬ 
tence after the narration of his results is “ The edible qualities of 
this Pea I have not tried, having but few.” To see the phenomenon 
as displayed in the last figure it would have been necessary for him 
to record the peas on ( i.e ., the cotyledon characters of the offspring 
of) each plant separately. He does not say he did this ; and, from 
the fact that when he made a separation of this kind, as in the 
sowing of the yellows and greens in F 2 , he expressly refers to it, 
we may suppose that if he had recorded them separately he would 
have said so. Besides there is no reason, which we can imagine, why 
he should do so. He probably left the plants in the ground until 
they were dry, and picked a few pods from each row at random. 
