Origin of Species Variorum

→ may, 1859 1860 1861 1866

in contrast with those spontaneously self-fertilised, may, as 1869 1872

→ and of some other genera, which can be far more easily 1860 1861 1866

and with all the species of the genus Hippeastrum, which can be far more easily 1859

Verbascum and Passiflora, can easily be 1869 1872

→ of another and 1859 1860 1861 1866

from a 1869 1872

→ than by their own pollen; and all the individuals of nearly all the species of Hippeastrum seem to be in this predicament. 1860 1861 1866

than by their own pollen. 1859

but not by pollen from the same plant, though this pollen can be proved to be perfectly sound by fertilising other plants or species. 1869 1872

↑ 1 blocks not present in 1859 1860 1861 1866; present in 1869 1872

In the genus Hippeastrum, in Corydalis as shown by Professor Hildebrand, in various orchids as shown by Mr. Scott and Fritz Müller, all the individuals are in this peculiar condition.

→ certain individual plants and 1859 1860 1861 1866

with some species, certain abnormal individuals, and in other species 1869 1872

→ of certain species 1859 1860 1861 1866

OMIT 1869 1872

→ self-fertilised! For instance, a bulb of Hippeastrum au- licum 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." 1866

self-fertilised! 1859 1860 1861

fertilised by pollen from the same individual plant! 1869 1872

→may,

as I

believe, be accounted for by

too close

interbreeding

inter-breeding

having been avoided.

Now let us turn to the results arrived at by

the

third most experienced hybridiser, namely, the Hon. and Rev. W. Herbert. He is as emphatic in his conclusion that some hybrids are perfectly

fertile—

fertile—as

....

fertile as the pure

parent-species—

parent-species—as

....

are Kölreuter and Gärtner that some degree of sterility between distinct species is a universal law of nature. He

experimentised

experimented

on some of the very same species as did Gärtner. The difference in their results may, I think, be in part accounted for by Herbert's great horticultural skill, and by his having

hot-houses

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

fertilized

fertilised

by C. revolutum produced a plant, which

~~(he says)~~

(he says)

I never saw to occur in a case of its natural fecundation." So that

here we

we here

have

perfect,

perfect

or even more than commonly

perfect

perfect,

fertility,

fertility

in a first cross between two distinct species.

This case of the Crinum leads me to refer to a

~~most~~

most

singular fact, namely, that

~~there are~~

there are

individual

plants,

plants

as with

certain species of

Lobelia,

Lobelia

→and of some other genera, which can be far more easily fertilised by

~~the~~

the

pollen →of another and distinct species, →than by their own pollen; and all the individuals of nearly all the species of Hippeastrum seem to be in this predicament. ↑ 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,

individuals

→of certain species can actually be hybridised much more readily than they can be →self-fertilised! For instance, a bulb of Hippeastrum au- licum 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."