370 
Tricotylous Races. 
the same culture from the seeds of a single seed-parent. 
This is especially the case in Antirrhinum majns and 
Scrophnlaria nodosa, in which species I have often pre- 
ferred as seed-parents, the tricotyls, whose first whorls 
were trimerous. Nevertheless they have not, as a rule, 
proved the better qualified to continue the character of 
the race. Further instances are afforded by Dipsacus 
sylvestris, Lychnis fulgens, Dracoccphalum moldavicwn, 
Dianthus barbatns and so 
on. In the spring of 1887 I 
had some tricotylous seed- 
lings of Acer Pscudo-Plata- 
nns ; two of them are now 
high trees, whose trunks bear 
their branches in trimerous 
whorls. 
The lateral branches of 
ternary main stems tend, as 
mi 
a rule, to revert to the de- 
cussate arrangement. Sub- 
terranean runners, (for in- 
stance in Valeriana officina- 
lis) and the secondary stems 
which are produced at the 
level of the ground (e. g., DiantJuis barbatus), afford, 
however, numerous exceptions. 
In tricotylous cultures, dicotylous individuals some- 
times become ternary later. Thus I possess a plant with 
ternary whorls of Aescithis Hippocastamnn (now 13 
years old), which only had two cotyledons, and from 
the same crop a plant which was tricotylous but has since 
produced leaves on the decussate plan only. In both 
specimens the change in the disposition of the leaves 
Fig. 75. Fagus syhatica. Tri- 
cotylous seedlings. A, with a 
ternary whorl of the first 
leaves ; B, with a leaf with 
two apices and a divided vein. 
