10 and 1.11.
The most interesting point in Hildebrand's experiments is the difference in the
effects of illegitimate fertilisation with a flower's own pollen, and with that
from a distinct plant of the same form. In the latter case all the flowers
produced capsules, whilst only 67 out of 100 of those fertilised with their own
pollen produced capsules. The self-fertilised capsules also contained seeds, as
compared with capsules from flowers fertilised with pollen from a distinct plant
of the same form, in the ratio of 72 to 100.
In order to ascertain how far the present species was spontaneously self-
fertile, five long-styled plants were protected by me from insects; and they
bore up to a given period 147 flowers which set 62 capsules; but many of these
soon fell off, showing that they had not been properly fertilised. At the same
time five short-styled plants were similarly treated, and they bore 116 flowers
which ultimately produced only seven capsules. On another occasion 13 protected
long-styled plants yielded by weight 25.9 grains of spontaneously self-
fertilised seeds. At the same time seven protected short-styled plants yielded
only half-a-grain weight of seeds. Therefore the long-styled plants yielded
nearly 24 times as many spontaneously self-fertilised seeds as did the same
number of short-styled plants.
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