91 inches, and the fifteen
self-fertilised plants 19.54 inches in height, or as 100 to 89. These
plants did not differ in fertility, as far as could be judged by the
number of capsules produced, for there were seventy-five on the crossed
side and seventy-four on the self-fertilised side.
Eschscholtzia californica.
This plant is remarkable from the crossed seedlings not exceeding in
height or vigour the self-fertilised. On the other hand, a cross greatly
increases the productiveness of the flowers on the parent-plant, and is
indeed sometimes necessary in order that they should produce any seed;
moreover, plants thus derived are themselves much more fertile than
those raised from self-fertilised flowers; so that the whole advantage
of a cross is confined to the reproductive system. It will be necessary
for me to give this singular case in considerable detail.
Twelve flowers on some plants in my flower-garden were fertilised with
pollen from distinct plants, and produced twelve capsules; but one of
these contained no good seed. The seeds of the eleven good capsules
weighed 17.4 grains. Eighteen flowers on the same plants were fertilised
with their own pollen and produced twelve good capsules, which contained
13.61 grains weight of seed. Therefore an equal number of crossed and
self-fertilised capsules would have yielded seed by weight as 100 to 71.
(4/4. Professor Hildebrand experimented on plants in Germany on a larger
scale than I did, and found them much more self-fertile.
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