Origin of Species Variorum

→ the process of artificial 1866 1869 1872

artificial 1859 1860 1861

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

may, 1859 1860 1861 1866

→ Verbascum and Passiflora, can easily be 1869 1872

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

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

→ from a 1869 1872

of another and 1859 1860 1861 1866

→ 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

than by their own pollen. 1859

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

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

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.

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

certain individual plants and 1859 1860 1861 1866

→ OMIT 1869 1872

of certain species 1859 1860 1861 1866

→ fertilised by pollen from the same individual plant! 1869 1872

self-fertilised! 1859 1860 1861

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

→ To give one 1869 1872

For 1859 1860 1861

with hybrid pollen of the same kind, their fertility, notwithstanding the frequent ill effects

from

manipulation, sometimes decidedly increases, and goes on increasing. Now, in →the process of artificial

fertilisation

fertilisation,

pollen is as often taken by chance (as I know from my own experience) from the anthers of another flower, as from the anthers of the flower itself which is to be fertilised; so that a cross between two flowers, though probably

often on

the same plant, would be thus effected. Moreover, whenever complicated experiments are in progress, so careful an observer as Gärtner would have castrated his hybrids, and this would have

insured

ensured

in each generation a cross with

the

....

pollen from a distinct flower, either from the same plant or from another plant of the same hybrid nature. And thus, the strange fact of

the

increase of fertility in the successive generations of artificially fertilised

hybrids

hybrids,

→in contrast with those spontaneously self-fertilised, may, as

as I

believe, be accounted for by

too close

inter-breeding

interbreeding

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—as

fertile—

fertile as the pure

parent-species—as

parent-species—

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

hothouses

hot-houses

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

fertilized

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

here we

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

....

singular fact, namely, that

there are

....

individual

plants,

plants

as with

certain species of

Lobelia

Lobelia,

→Verbascum and Passiflora, can easily be fertilised by

the

....

pollen →from a distinct species, →but not by pollen from the same plant, though this pollen can be proved to be perfectly sound by fertilising other plants or species. 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. ↑ So that →with some species, certain abnormal individuals, and in other species all the

individuals

individuals,

→OMIT can actually be hybridised much more readily than they can be →fertilised by pollen from the same individual plant! →To give one instance, a bulb of Hippeastrum aulicum

produced

pro- duced

four flowers;