Tricotylons Half Races. 379 
cases, can be clearly recognized as consisting of two 
leaves (Fig. 81 D). 
The fact that so rare a teratological phenomenon 
should occur so regularly in two well-known varieties of 
the same species, the one uniform red, and the other 
striped yellow and red means perhaps that the char- 

acter in question has existed for a long time in the Snap- 
dragon and will be found, after a close investigation, 
to exist in other cultivated varieties also and possibly 
even in the wild ancestral form. Of course the fact that 
I found them in a tricotylous race need not necessarily 
indicate a causal relation between this character and 
tricotyly, because, at the beginning of my cultures, I 
started by selecting the tricotyls and continued the race 
from their seeds alone. If such a relation did exist the 
fact that the anomaly occurs both on dicotylous and on 
tricotylous individuals would be very important, for it 
would show that it is not the visible tricotyly itself, but 
some corresponding internal character, which must be 
regarded as the cause. It is to be hoped that the abund- 
ance in which the anomaly can now be obtained will 
render possible a closer examination of this problem. 
4. TRICOTYLOUS HALF RACES. 
Occasional tricotylous seedlings will be found among 
samples of seed in very many species. All that is neces- 
sary, therefore, to start a culture is to buy a sufficient 
quantity of seed and to sow it. The seed will either 
give no aberrant forms, or very few, or a considerable 
number. In the first case the possibility of obtaining 
tricotyls still remains open if a larger quantity of seed 
is sown. In the second case the variants can be used as 
