hybridiser, namely, the Honourable and
Reverend W. Herbert. He is as emphatic in his conclusion that some
hybrids are perfectly fertile as fertile as the pure parent-species as
are Kolreuter and Gartner that some degree of sterility between
distinct species is a universal law of nature. He experimentised on
some of the very same species as did Gartner. The difference in their
results may, I think, be in part accounted for by Herbert s great
horticultural skill, and by his having hothouses at his command. Of his
many important statements I will here give only a single one as an
example, namely, that every ovule in a pod of Crinum capense
fertilised by C. revolutum produced a plant, which (he says) I never
saw to occur in a case of its natural fecundation. So that we here
have perfect, or even more than commonly perfect, fertility in a first
cross between two distinct species.
This case of the Crinum leads me to refer to a most singular fact,
namely, that there are individual plants, as with certain species of
Lobelia, and with all the species of the genus Hippeastrum, which can
be far more easily fertilised by the pollen of another and distinct
species, than by their own pollen. For these plants have been found to
yield seed to the pollen of a distinct species, though quite sterile
with their own pollen, notwithstanding that their own pollen was found
to be perfectly good, for it fertilised distinct species. So that
certain individual plants and all the individuals of certain species
can actually be hybridised much more readily than they can be
self-fertilised! For instance, a bulb of Hippeastrum aulicum produced
four flowers; three were fertilised by Herbert with their own pollen,
and the fourth was subsequently fertilised by the pollen of a compound
hybrid descended from three other and distinct species: the result was
that the ovaries of the three first flowers soon ceased to grow, and
after a
few days perished entirely, whereas the pod impregnated by the pollen
of the hybrid made vigorous growth and rapid progress to maturity, and
bore good seed, which vegetated freely. In a letter to me, in 1839,
Mr. Herbert told me that he had then tried the experiment during five
years, and he continued to try it during several subsequent years, and
always with the same result. This result has, also, been confirmed by
other observers in the case of Hippeastrum with its sub-genera, and in
the case of some other genera, as Lobelia, Passiflora and Verbascum.
Although the plants in these experiments appeared perfectly healthy,
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