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Show 66 INHERITANCE. CHAP. XIV. . . · s case of a ram of a goa t-likc for exportation.6 Godino has given a curJou . . duced offs rin breed of sheep from the Cape of Good Hope, which pr~ "th P ~ hardly to be distinguished from himself, when crosse WI owes o twelve other breeds. But two of these half-bred ewes, wh~n pbut tdo a merino ram produced lambs close1 y r·e som bl"In g the mennoth ree . G:iJ.·ou de Buza;eingues 7 found that of_ two rac~s ~f Fron~h sheo~ 0 °r::~s of one when crossed during successive generatiOns With mertillh , ' th th wos of the o or r-ace. yielded up their character far sooner an ~ e . . ds of shoe Sturm and Girou have given analogous cases with other bree 1 th t and with cattle the r)ropotoncy running. in these cases thr~ug 1th to mha e side· but I was' assured on good authon·t y i·l l So u th Am.o nc'ab ' a w on elL • niata' cattle arc crossed wi· th common ca ttlc , tho ug h the ruata ree t JS pro.- otent whether males or females are used, yet t~at ~he prepo ency IS ~trongest throurrh the female line. The Manx cat IS tailless and ha~ lon~ hind legs; Dr. ~:>Wilson crossed a male Manx with com~on cats, an 'ou of twenty-three kittens, seventeen were destitute of tmls _; but when ~be female Manx was crossed by common_ male cat~ all the kittens had tails, though they were generally short and Imperfect. . . In making reciprocal crosses between pouter and fantail pigeons, t~e pouter-race seemed to be prepotent thro~gh both s~xo~ ove~· the fantml. But this is probably due to weak power ill the fantail rather than to any unusually strong power in the pouter, for I have obsor:e~ t~at barbs al~o preponderated over fantails. This we~kne~s of transmissiO.n ~ the fantail, though the breed is an ancient one, IS smd 9 to be general, but I bav_e observed one exception to the rule, namely, in a cross between a fant~Il and laugher. The most curious inst.'tncc _known to me of weak power~ both sexes is in the trumpeter pigeon. This breed has been well known for at least 130 years: it breeds perfectly true, as I have been assure~ by those who have long kept many birds: it is characterised by a peculiar. tuft of feathers over the beak, by a crest on the head, by a most peculiar coo quite unlike that of any other breed, and by muoh-fe~thered feet. I ha~e crossed both sexes with turbits of two sub-broods, with almond tumblers, spots, and runts, and reared many mongrels and rocross~d them;. and though the crest on tho head and feathered feet were inhented (as IS generally the case with most breeds), I have never seen a vestige of the tuft ov~r the beak or heard the peculiar coo. Boitard and Corbio 10 assert that this is tho invariable result of crossing trumpeters with any other b~eed: Neumeister,11 however, states that in Germany mongrels have been obtamed, though very rarely, which were furnished with the tuft and would trumpet: but a pail· of these mongrels with a tuft, which I imported, never trumpeted. Mr. Brent states 12 that the crossed offspring of a trumpeter were crossed 6 Quoted by Bronn,' Geschichte der Natur,' b. ii. s. 170. See Sturm, 'Ueber Racen,' 1825; s. 104-107. For the niata cattle, see my 'Journal of Researches,' 1845, p. 146. 7 Lucas, 'l'Heredite Nat.,' tom. ii. p. 112. s Mr. Orton, ' Physiology of Breeding,' 1855, p. 9. 9 Boitarcl and Corbie, ' Les Pigeons,' 1824, p. 224. 10 • Les Pigeons,' pp. 168, 198. n 'Das G:mze,' &c., 1837, s. 39. 12 • The Pigeon Book,' p. 46. CHAr. XIV. PREPOTENCY OF TRANSMISSION. 67 with trumpeters for three generations, by which time the mongrels had 7-Sths of this blood in the:iJ.· veins, yet the tuft over the beak did not appear. At tho fourth generation the tuft appeared, but the birds, though now having l 5-16ths trumpeter's blood, still did not trumpet. This case well shows the wide difference between inheritance and prepotency; for here we have a well-established old race which transmits its characters faithfully, but which, when crossed with any other race, has the feeblest power of transmitting its two chief characteristic qualities. I will give one other instance with fowls and pigeons of weakness and strength in tho transmission of the same character to their crossed offspring. The Silk-fowl breeds true, and there is reason to believe is a very ancient race; but when I reared a large number of mongrels from a Silk-hen by a Spanish cock, not one exhibited even a trace of the so-called silkiness. Mr. Hewitt also assetts that in no instance are the silky feathers transmitted by this brood when crossed with any other variety. But three birds out of many raised by Mr. Orton from a cross between a silk-cock and a bantam- hen, had silky feathers.13 So that it is certain that this breed very seldom has the power of transmitting its peculiar plumage to its cwssed progeny. On the other hand, there is a silk sub-variety of the fantail pigeon, which has its feathers in nearly the same state as in the Silk-fowl: now we have already seen that fantails, when crossed, possess singularly weak power in transmitting their general qualities; but the silk subvariety when crossed with any other small-sized race invariably transmits its silky feathers! 14 The law of prepotency comes into action when species are crossed, as with races and individuals. Gartner has unequivocally shown 15 that this is the case with plants. To give one instance: when Nicotiuna paniculata and vincceflora are crossed, the character of N. paniculuta is almost completely lost in the hybrid; but if N. quadrivalvis be crossed with N. vincrejlora, this latter species, which was before so prepotent, now in its turn almost disappears under the power of N. qttadrivalvis. It is remarkable that the prepotency of one species over another in transmission is quite independent, as shown by Gartner, of the greater or less facility with which the one fertilises the other. With animals, the jackal is prepotent over the dog, as is stated by Flourens who made many crosses between these animals; and this was likewise the case with a hybrid which I once saw between a jackal and terrier. I cannot doubt, from the observations of Colin and others, that the ass is prepotent over the horse; the prepotency in this instance Tunning more strongly through the male than through the female ass; so that the mule resembles the ass more closely than does the hinny.16 The 13 'Physiology of Breeding,' p. 22; Mr. Hewitt, in 'The Poultry Book,' by 'fegetmeicr, 1866, p. 224. 14 Boitard and Corbie, 'Les Pigeons,' 1824, p. 226. 15 ' Basta1·derzeugung,' s. 256, 290, &c. Naudin ('Nouvelles Archives du Museum,' tom. i. p. 149) gives a striking instance of prepotency in Datura stramonium when crossed with two other species. 16 Flourens, 'Longevite Humaine,' p. 144, on crossed jackals. With respect to the difference between the F 2 |