Crossing of Bearded and Beardless Wheats. 
51 
as the parent. In this case, then, there was no appearance 
of an intermediate form resulting in the production of 
a semi-bearded type as one might have expected from the 
example quoted previously. The reciprocal cross gave the 
same result. The hybrids, then, were similar to the beardless 
parent, and where that was chosen as the mother one might 
well have supposed that the cross had failed to take, and 
normal grain had been set. Mendel termed the character 
which appeared in the hybrid, to the exclusion of the 
other, “ dominant,” and its fellow “ recessive.” Using this 
terminology, the beardless condition is said to be dominant 
over the bearded, and the bearded recessive to the beardless. 
On sowing the grains of the hybrid, they produced beard- 
less and bearded offspring, three of the former being present 
to each of the latter. On the assumption that the hybrid 
produces gametes carrying either the beardless or the bearded 
character, this result is readily explained. The possible 
chances of combination are represented diagrammatically as 
before : — 
Pollen grains Egg cells 
Male gametes Female gametes 
A Beardless 
Beardless A 
They are A A, AB, BA, BB. Where A and A meet or 
B and B, the resulting plant will be beardless in the one case 
and bearded in the other. Where the unlike gametes A and B 
meet, as in the original cross, then they give rise to beardless 
plants, A being dominant over B. 
If this explanation is correct, then two of the three beard- 
less plants, namely AB and BA, should give a mixed progeny 
similar to that of the original hybrid, whilst the third, A A, 
though indistinguishable by eye, should breed true. The plant 
BB, showing the recessive character, should also breed true. 
The succeeding generation (Fig. 2, F 3 ) showed that this 
was the case. On the average, two out of every three of the 
beardless plants (f 2) threw bearded as well as beardless 
individuals, whilst one bred true to type. All plants with 
beards, that is, the recessives, on the contrary, bred true. 
The beardless plants which give a mixed progeny corre- 
spond with the intermediates of the previous case, but owing 
to the complete dominance of the one character they are 
inseparable as far as external appearances go. 
Neither of these crosses has produced fresh types in a 
stable condition, but they supply the breeder with some 
essential facts which may be stated here and their application 
