5 seeds. In 1863 I tried a much better experiment: a
long-styled plant was grown by itself, miles away from any other plant, so that
the flowers could have received only their own two kinds of pollen. The flowers
were incessantly visited by bees, and their stigmas must have received
successive applications of pollen on the most favourable days and at the most
favourable hours: all who have crossed plants know that this highly favours
fertilisation. This plant produced an abundant crop of capsules; I took by
chance 20 capsules, and these contained seeds in number as follows:--
20 20 35 21 19
26 24 12 23 10
7 30 27 29 13
20 12 29 19 35
This gives an average of 21.5 seeds per capsule. As we know that the long-styled
form, when standing near plants of the other two forms and fertilised by
insects, produces on an average 93 seeds per capsule, we see that this form,
fertilised by its own two pollens, yields only between one-fourth and one-fifth
of the full number of seed. I have spoken as if the plant had received both its
own kinds of pollen, and this is, of course, possible; but, from the enclosed
position of the shortest stamens, it is much more probable that the stigma
received exclusively pollen from the mid-length stamens; and this, as may be
seen in Table 4.
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