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Production of Hybrids in a state of nature. Note Ch 6

Gærtner p. 583 to 606 (say little) As it has been an old hypothesis that the varied forms in many genera have resulted from the crossing of a few species, — a view even lately sustained by the Dean of Manchester. I may make a few remarks on the subject, & for a full discussion as far as regards plants, the reader may consult Gærtner (* chapter give). This latter author doubts, & apparently with good reason that far greater majority of reported cases, & shows that the intermedial character, often relied on, is not very trustworthy, as a very large proportion of really known hybrids are not exactly intermediate between their pure parent. Even sterility is not a sure test, as many examples in certain genera as in Dianthus & Verbascus occur from unknown cases sterile. But Gærtner does admit some cases. (Example?) Herbert—Crinum wild. Amaryllidae p 343 2 But as these Hybrids in the far greater majority cases are in some degree sterile, as the pollen of either parent, which in most cases will be growing in the vicinity has perpetual effect over the pollen of the hybrid itself then will be the strongest tendency for the hybrid to die out from sterility or to be absorbed in a few generations into either parent form and tend of themselves to go back if not selected. — So this may be added that very rarely will there be peculiar conditions present, which are better adapted to the structure & constitution of the hybrid then to either parent.

[in margin:] My case of Verbascum & many other cases seen

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Herbert Amaryll. p. 343 Crinum wild hybrid

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& without such conditions be present there will be no tendency to preserve the new hybrid form as every plant seeds superabundantly & the best adapted alone will reach maturity.

But I am far from denying probability of such crosses having occasionally taken place, when two lands joined with very close spec; but it is only an hypothesis by w facts I believe to up it. These remarks are all applicable to animals. Several extraordinary crosses been observed in nature. Possibly the pheasant in England can hardly be considered in a perfect state of nature, but we have now recorded -- cases of crosses between pheasant & Grouse. — In Scandinavia between two species of Grouse. In In England between gold & common pheasant. But this is still less state of nature. [illeg] between pheasants. In Ducks (?) Crow & Hooded crow.—These cases are of interest in showing no revulsion between species. ‒ In none of these cases is there any reason to think that par pure specific forms has been altered. (*about Goulds view of Ringed Pheasant.)

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It must be considered somewhere the supposed law of Gærtner of real species producing with a 3d from very distinct offspring.

p. 5811 Variation in Lychnis Petunia

against law

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Mr Wollaston believes that the the insects of Madeira owing to their isolated position, & hence I presume to the ill-effects of interbreeding, are have become in several cases (   ) reduced in size. On comparing some of the birds, obtained by Mr E. Vernon Harcourt in this same island, with British specimens, I find that these & Rock Pigeons are smaller than ordinary British specimens

Some other species seem to be of exactly of the same size. Again at the Galapagos isld (Journal of Researches p. 380) the two of the very few birds which are not confined to the archipelago, are sma smaller than specimens from elsewhere: but as the species & several other birds which are considered more or less doubtfully as distinct species, are smaller than the representative species on the continent; I conclude that c in this & the other cases it must remain doubtful, whether the conditions of existence are not sufficient to account for the reduced size