Illustration: Fig. 2.—Head of Japan or Masked Pig. The Japan pig (_S. pliciceps_ of Gray), which was formerly exhibited in the Zoological Gardens, has an extraordinary appearance from its short head, broad forehead and nose, great fleshy ears, and deeply furrowed skin. Figure 2 is copied from that given by Mr. Bartlett.[10] Not only is the face furrowed, but thick folds of skin, which are harder than the 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 this might have been inferred even from the fact that its young are not longitudinally striped; for this is a character common to all the species included within the genus _Sus_ and the allied genera whilst in their natural state.[11] Dr. Gray[12] has described the skull of this animal, which he ranks not only as a distinct species, but places it in a distinct section of the genus. Nathusius, however, after his careful study of the whole group, states positively (‘Schweineschädel’ s. 153-158). that the skull in all essential characters closely resembles that of the short-eared Chinese breed of the _S. indicus_ type. Hence Nathusius considers the Japan pig as only a domesticated variety of _S. indicus_: if this really be the case, it is a wonderful instance of the amount of modification which can be effected under domestication. Formerly there existed in the central islands of the Pacific Ocean a singular breed of pigs. These are described by the Rev. D. Tyerman and G. Bennett[13] as of small size, hump-backed, with a disproportionately long head, with short ears turned backwards, with a bushy tail not more than two inches in length, placed as if it grew from the back. Within half a century after the introduction of European and Chinese pigs into these islands, the native breed, according 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]