(1 2(a)

Mr Herbert considers without doubt old variety more likely to reproduce itself than new—but he throws doubt on this, as if not necessarily effect of ages, but of the chances.—

Negatives a relation between facility in sporting and hybridisation.— but says that stands to reason that the pollen of plant liable to sport does not produce such uniform effects on offspring—as one that does not.—but believes there would be no difference between a permanent variety and easily convertible species: all facts about the reappearance of character must be inferred from the animal kingdom.

The non relation of hybridizing power & variation goes far to overturn my views of fixity of character, being dependent on age, & consequently on time after certain period having any further effect on characters.—& if Mr Herbert is right there should be no effect difference when an Esquimaux dog & Wolf is crossed with other dog: yet to be

[1v]

sure, the Esquimaux & common Dog, breed freely whilst the Holly thorn varieties of plants which grow near each other & do not cross, must have some repulsive tendency.—

The greater fertility of two hybrids very perplexing to my view of hybrids going back to old type when crossed wrong view, because fertility increase by cross with another hybrid with one parent & so becoming fertile.—it is new element the offspring reverting to the constitution most congenial to site—

The fixity of character resistance to hybridisation being consequence of old age of species (inexplicable by Mr Herbert) is so simple an explanation, that I can hardly give it up, though these some species varying & yet not hybridising almost overthrows it.— Is there any case of species which can easily be hybridised & hybrids be fertile & yet does not vary?—

[2]

negatives isolation in series in non-hybridising genera close species of Crinum & Iris will not cross, yet being many & local, probably according to my theory recently produced.

In fact at present all that can be said, is that in wild species, some difference of unknown nature, which cannot be predicated, but which is not always present, originates, which causes two not to breed, or if they do breed, causes offspring to be sterile. And this difference whatever it may be has never been produced amongst tame variations. I must state that no relation of hybridising & variability is opposed to the old view, which still seems innately probable.—

Quote Herbert.— But then we find equally inexplicable amt of variability in organisms taken

[2v]

out of their proper conditions (but here offspring never rendered infertile), & we cannot take these cases of infertility, (we cannot any more explain them) as any criterion of what are species, & why shd we in case of crossing.—

Not more easy to hybridise cultivated than uncultivated Plants