66 inches, so that the
crossed plants are to the self-fertilised in height as 100 to 76. It
should be observed that this difference is not due to a few of the
crossed plants being extremely tall, or to a few of the self-fertilised
being extremely short, but to all the crossed plants attaining a greater
height than their antagonists. The three pairs in Pot 1 were measured at
two earlier periods, and the difference was sometimes greater and
sometimes less than that at the final measuring. But it is an
interesting fact, of which I have seen several other instances, that one
of the self-fertilised plants, when nearly a foot in height, was half an
inch taller than the crossed plant; and again, when two feet high, it
was 1 3/8 of an inch taller, but during the ten subsequent days the
crossed plant began to gain on its antagonist, and ever afterward
asserted its supremacy, until it exceeded its self-fertilised opponent
by 16 inches.
The five crossed plants in Pots 1 and 2 were covered with a net, and
produced 121 capsules; the five self-fertilised plants produced
eighty-four capsules, so that the numbers of capsules were as 100 to 69.
Of the 121 capsules on the crossed plants sixty-five were the product of
flowers crossed with pollen from a distinct plant, and these contained
on an average 5.23 seeds per capsule; the remaining fifty-six capsules
were spontaneously self-fertilised.
Pages:
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66