External Conditions and Hereditary / 'allies. 487 
the main stem, and they produce a correspondingly smaller 
number of synootyls, but only in the proportion of 87 to 
80%, on an average for 12 plants. If the seeds of single 
inflorescences are harvested in three lots in such a way 
that the outer, inner and middle areas are separated, the 
former generally contain slight- 
ly more syncotyls, for the fruits 
in the middle of the head tend 
to be somewhat weaker. From 
each of these three groups I 
have allowed the best seedlings 
to flower and bear fruit, but 
I found no essential difference 
in their hereditary values. It 
appears that improved condi- 
tions during the early stages of 
the plant, have some small in- 
fluence in a positive direction, 
but crowding in later life and 
partial removal of the leaves 
during the flowering period had 
little noticeable effect (1891). 
Furthermore a culture on good 
Fig. 103. Helianthus annuus 
syncotyleus. A and B, seed- 
lings whose plumule has 
not developed during the 
course of several weeks ; the 
syncotyl is abnormally en- 
larged. C, Amphi-syncotyl- 
pus plant, also with inhib- 
ited development of the 
stem. 
sandy soil, instead of garden 
soil, made no difference in the values (1892). 
Striking exceptions, however, sometimes occurred, for 
instance in the year 1891, when three plants in my main 
culture became affected with Peziza a short time after 
flowering, and died, not however without ripening some 
of their seed. These three produced the smallest values 
of the whole group. (76, 84 and 85% as against 86 to 
99% V But perhaps they were the weakest individuals 
and contracted the disease for this reason. 
