The presence of these beaded hairs in both forms, though
occupying such different positions, shows that they are probably of considerable
functional importance. They would serve to guard the stigma of each form from
its own pollen; but in accordance with Professor Kerner's view their chief use
probably is to prevent the copious nectar being stolen by small crawling
insects, which could not render any service to the species by carrying pollen
from one form to the other. (3/23. 'Die Schutzmittel der Bluthen gegen
unberufene Gaste' 1876 page 37.)
The flowers are so small and so crowded together that I was not willing to
expend time in fertilising them separately; but I dragged repeatedly heads of
short-styled flowers over three long-styled flower-heads, which were thus
legitimately fertilised; and they produced many dozen fruits, each containing
two good seeds. I fertilised in the same manner three heads on the same long-
styled plant with pollen from another long-styled plant, so that these were
fertilised illegitimately, and they did not yield a single seed. Nor did this
plant, which was of course protected by a net, bear spontaneously any seeds.
Nevertheless another long-styled plant, which was carefully protected, produced
spontaneously a very few seeds; so that the long-styled form is not always quite
sterile with its own pollen.
Pages:
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185