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Show 70 DOMESTIC PIGS. C IIAl', Ill. is the face furrowed, but thick folds of skin, which arc harder than tho other parts, almost like the plates on the Indian rhinoceros, hang about the shoulders and rump. It is coloured black, with white feet, and breeds true. That it has long been domesticated there can be little doubt; and thitl might have been inferred oven from tho fact that its young are not longitudinally striped; for this is a chn.ractor common to all the species included within tho genus Sus ::mel tho allied genera whilst in their natural statcY Dr. Gray 12 has described the skuU of this animal, which he ranks not only as a distinct species, but places it in a distinct section of the genus. N athu ius, however, after his careful study of the whole group, states positively (Schwcincsch~Ldel, s. 163-158) that the skull in all es. ential characters closely resembles that of the short-cared Chinese breed of the S. Indica type. Donee Nathu. ius considers tho J !\pan pig as only a domesticated variety of S. Indica: if this really be the case, it is a wonderful instance of tho amount of modification whieh can be e:ITocted under domestication. Formerly there existed in the central islands of tho Pacific Ocean a singular breed of pigs. 'rheso arc described by the Hov. D. 'l'ycrman and G. Bonnettl3 as of small size, humpbacked, with a disproportionately long head, with short ears turned backwards, with n. bushy tail not more than two inches in length, placed as if it grew from the back. Within half a century after tho introduction into those islands of European and Chinese pigs, tho native breed, n.ccording to the above authors, became almost completely lost by being repeatedly crossed with them. Secluded islands, as might have been expected, seem favourable for the production or retention of peculiar breeds; thus, in the Orkney Islands, the hogs have been described as very small, with erect and sharp ears, and "with an appearance altogether different from the hogs brought from the south." 14 Seeing how different tho Chinese pigs, belonging to the Sus Indica type, arc in their osteological characters and in external 11 Sclator, in 'Proc. Zoolog. Soc.,' Feb. 26th , 1861. 12 'Proc. Zoolog. Soc.,' 1862, p. 13. 13 'Journul of Voyages and 'fravols from 1821 to 1829,' vol. i. p. 300. 14 Rev. G. Low, 'Fauna Orcnd.ensis,' p. 10. See also Dr. Ilibbert's account of the pig of Lhe Shetland I slands. CHAP. III. TIIEIR VARIATION. 71 appearance from the pigs of the S. scrofa type, so that they must be considered specifically distinct, it is a fact well deserving attention, that Chinese and common pigs have been 1·epeatedly crossed in various manners, with unimpaired fertility. One great breeder who had used pure Chinese pigs assured mo that the fertility of the half-breeds inter se and of their recrossed progeny was actually increased ; and this is the general belief of agriculturists. Again, tho Japan pig or S. pliciceps of Gray is so distinct in appearance from all common pigs, that it stretches one's belief to the utmost to admit that it is simply a cl?mes~ic variety ; ye~ this brood has been found perfectly fertile With the Berkshu·e breed; and Mr. Eyton informs me that he paired a half-bred brother and sister and found them quite fertile together. The modifications of the skull in the most highly cultivated races are wonderful. To appreciate tho amount of change, N athusius' work, with its excellent figures, should be studied. The whole of the exterior of the skull in all its parts has been altered; the hinder surface, instead of sloping backwards, is directed forwards, entailing many changes in other parts ; the front of the head is deeply concave ; tho orbits have a different shape ; the auditory meatus has a different direction and shape; tho incisors of the upper and lower jaws do not touch each other, and they stand in both jaws above ~he plano of the molars; the canines of the upper jaw stand m front of those of tho lower jaw, n.nd this is a remarkable anomaly: the articular surfaces of the occipital condyles are so greatly changed in shape, that, as Nathusius remarks (s. ~33), no naturalist, seeing this important part of the skull by Itself, would suppose that it belonged to the genus Sus. These and various other modifications, as Nathusius observes, ~a~ hardly Le considered as monstrosities, for they are not inJUnous, and are strictly inherited. The whole head is much shortened.; thus, whil~t in common breeds its length to that of the body Is as 1 to 6, m tho "cultur-races" tho proportion is as 1 to 9, and even recently as 1 to 1VG 'l1he following woodcut w 1& 'Dio llaccn clos chweines,' s. 70. 1 h These woodcuts nrc copied from engravings given in Mr. . 'idncy's oxcollonL edition of 'Tho Pig,' by Y ouaLt, 1860. See pp. 1, 16, 19. |