We thus see what a great
effect, as far as fertility is concerned, was produced by a cross
between the two varieties, which had been long exposed to different
conditions, in comparison with self-fertilisation; the fertilisation
having been in both cases of the legitimate order.
Primula sinensis.
As the Chinese primrose is a heterostyled or dimorphic plant, like the
common cowslip, it might have been expected that the flowers of both
forms when illegitimately fertilised with their own pollen or with that
from flowers on another plant of the same form, would have yielded less
seed than the legitimately crossed flowers; and that the seedlings
raised from illegitimately self-fertilised seeds would have been
somewhat dwarfed and less fertile, in comparison with the seedlings from
legitimately crossed seeds. This holds good in relation to the fertility
of the flowers; but to my surprise there was no difference in growth
between the offspring from a legitimate union between two distinct
plants, and from an illegitimate union whether between the flowers on
the same plant, or between distinct plants of the same form. But I have
shown, in the paper before referred to, that in England this plant is in
an abnormal condition, such as, judging from analogous cases, would tend
to render a cross between two individuals of no benefit to the
offspring. Our plants have been commonly raised from self-fertilised
seeds; and the seedlings have generally been subjected to nearly uniform
conditions in pots in greenhouses.
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