But the small number of fruit yielded by the 18 long-styled
flowers in the first line was probably accidental, and if so, the difference in
the proportion of legitimately and illegitimately fertilised flowers which yield
fruit is really greater than that represented by the ratio of 100 to 35. The 18
long-styled flowers illegitimately fertilised yielded no seeds,--not even a
vestige of one. Two long-styled plants which were placed under a net produced
138 flowers, besides those which were artificially fertilised, and none of these
set any fruit; nor did some plants of the same form which were protected during
the next summer. Two other long-styled plants were left uncovered (all the
short-styled plants having been previously covered up), and humble-bees, which
had their foreheads white with pollen, incessantly visited the flowers, so that
their stigmas must have received an abundance of pollen, yet these flowers did
not produce a single fruit. We may therefore conclude that the long-styled
plants are absolutely barren with their own-form pollen, though brought from a
distinct plant. In this respect they differ greatly from the long-styled English
plants of P. officinalis which were found by me to be moderately self-fertile;
but they agree in their behaviour with the German plants of P. officinalis
experimented on by Hildebrand.
Pages:
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157