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Show 102 CAUSES WlliCII CllECK CHAP. XVI. the Falkland Islands the cattle are breaking up into herds of different colours; and those on the higher ground, which are generally white, usua11y breed, as I am informed by Admiral Sulivan, three months earlier than those on the lowlands; and tllis would manifestly tend to keep the herds from blending. Certain dom.estic races seem to prefer breeding with their own kind; and tllis is a fact of some importance, for it is a step to·wards that instinctive feeling which helps to h:eep closely allied species in a state of nature distinct. vVe have now abundant evidence that, if it were not for this feeling, many more hybrids would Le naturally produced than is the case. vVe have seen in the first chapter that the alco dog of Mexico dislikes clogs of other breeds ; and the hairless dog of Paragnay mixes less readily with the European races, t.ban the latter do with each other. In Germany the female Spitz-dog is said to receive the fox more readily than will other dogs; a female Australian Dingo in England attracted the wild male foxes. But these differences in the sexual instinct and attractive power of the various breeds may be wholly due to their descent from distinct species. In Paraguay the horses have much freedom, and an excellent observer 4 believes that the native horses of the same colour and size prefer associating with each other, and that the horses which have been imported from Entre Hios and Banda Oriental into Paraguay likewise prefer associating together. In Oircassia six sub-races of the horse are known and have received distinct names; and a native proprietor of rank 5 asserts that horses of three of these races, whilst living a free life, almost always refuse to mingle and cross, and will even attack each other. It has been observed, in a district stocked with heavy Lincolnshire and light Norfolk sheep, that both kinds, though bred together, when turned out, " in a short time separate to a sheep;" the Lincolnshires drawing off to the rich soil, and the N orfolks to their own dry light soil ; and as long as there is plenty of grass, "the two breeds keep themselves as distinct as rooks and pigeons." In this case different habits of 4 Rcnggcr, • Saugcthicrc von Paraguay,' s. 336. 5 See a memoir by l\'Il\1. Lherbette and De Quatrefagcs, in ' Bull. Soc. d'Acclimut.,' tom. viii., July, 1861, p. 312. CITAP. XVL TilE CROSSING OF VARIETIES. 103 lifo tend to koep the races distinct. On one of the Faroe islauds, not more than half a mile in diameter, the half-wild native black sheep are said not to have readily mixed with the imported white sheep. It is a more curious fact that the semimonstrous ancon sheep of modern origin "have been observed to keep together, separating themselves from the rest of the flock, when put into enclosures with other sheep." 6 vVith re::;pect to fallow deer, which livo in a semi-domestic.ated condition, l\Ir. Bennett 7 states that the dark and pale coloured herds, which have long been kept together in the Forest of Dean, in High l\Ieadow vVood.s, and in the New Forest, have never been known to mingle: the dark-coloured deer, it may be added, are believed to have been first brought by James I. from Norway, on account of their greater hardiness. I imported from the island of Porto Santo two of tho feral rabbits, which differ, as described in the fourth chapter, from common rabbits; botll proved to be males, and, though they lived during some years in the Zoological Gardens, the superintendent, l\Ir. Bartlett, in vain endeavoured to make them breed with various tame kinds; but whether this refusal to breed was due to any change in instinct, or simply to their extreme wildness ; or whether confinement had rendered them sterile, as often occurs, cannot be told. \Vhilst matching for the sake of experiment many of the most distinct breeds of pigeons, it frequently appeared to me that the birds, though faithful to their marriage vow, retained some desire after their own kind. Accordingly I asked l\Ir. \Vicking, who has kept a larger stock of various breeds together than any man in England, whether he thought that they would prefer pairing with their own kind, supposing that there were males and females enough of each ; and he without hesitation answered that he was convinced that this was the case. It has often been noticed that the dovecot pigeon «eems to have an actual aversion towards the several fancy breeds; 8 yet all have 6 For the Norfolk sheep, see Murshall" s 'Rural Economy of Norfolk,' vol. ii. p. 13G. See Rev. L. Landt's ' Description of Faroe,' p. 66. For the aneon sheep, see ' Phil. Tran act.,' 1813, p. 90. 7 White's 'Nat. Hi:;t. of Selbourne,' edited by Bennett, p. 39. With respect to the origin of the dtuk-colourecl doer, see ' Some Account of English Deer Parks,' by E. P. Shirley, Esq. s • The Dovecote,' by the Rev. E . S. Dixon, p. 155; Bechstein, 'Naturgesch. Doutschlands,' Band iv., 1795, s. 17. |