Letter to the Rev. John Bachman, D.D., on the question of hybridity in animals : considered in reference to the unity of the human species / by Samuel George Morton.
- Samuel George Morton
- Date:
- 1850
Licence: Public Domain Mark
Credit: Letter to the Rev. John Bachman, D.D., on the question of hybridity in animals : considered in reference to the unity of the human species / by Samuel George Morton. Source: Wellcome Collection.
Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)
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![other words, the mixed progeny hegins and ends with the first cross. A large proportion of the known mixed breeds belong to this class, and they embrace animals of entirely different genera. Several of them have been indicated in the foregoing pages ; and for some curious infor- mation on this head, the reader is referred to the researches of M. Selys- Longchamps, who has recorded authenticated examples of hybrids of twenty-four crosses between different species of swan, goose and duck, all of which proved sterile excepting those between Anser cygnoides and .1. dnereus, Cygnus olor and C. mutabilis, and Anas boschas and A. acuta* Indeed, nearly all domesticated birds, however different in generic relations, are capable of producing a mule offspring by mingling with each other. The second degree of hybridity is that in which the hybrids, whether generic or specific, are incapable of re-producing inter se, but multiply, to any extent, by uniting the hybrid with a full-blood animal of either of the parent stocks. The American bison, Bos Americanus, re-pro duces in this way with the common breed of cattle, as you have fully shown ; and Kalm, the Swedish traveller, states that these animals mixed with each other independently of the influence of domestication. The same remark is true with respect to all the known species of the genus Bos, whether in Asia, Africa or America ; and this second remove from the original stock, is capable, so far as my knowledge troes, of breeding inter se and without limit, provided a sufficient number of hy- brids of the same grade are brought together, to prevent the stock from being destroyed by too close inter-breeding. Races might be formed and perpetuated in this way. were they worth the trouble ; but this not being the case, the hybrids are permitted to lined with the parent stocks, in which they soon become lost, on account of the great prepon- derance of individuals of those stocks. The several species of goats, as we have seen, belong to this class of hybrid-forming animals. So also various other animals capable of domestication, as 1 have already pointed out, especially in my Essay. I will now only add two other examples. Two specie- of ferrets, Mustelafuro and M. putoriug, are often crossed in England, in order to obtain improved breeds ;f and two doves, the common turtle, Columba turtur, and the collared turtle, C. risoria, though specifically and remarkably different from each other, unite to- gether, and, according to Beckstein, produce fruitful hybrids.]; •Hybrides des Anatidees. Bulletin de I'Acad. Roy. de Bruxelles. T. XII. f Bewick. Quadrupeds, p. 252. $ Singing Birds, p. 287.](https://iiif.wellcomecollection.org/image/b21142592_0013.jp2/full/800%2C/0/default.jpg)
