1862. ] DR. J. E. GRAY ON THE JAPANESE PIG. MW 
1. Face smooth, or nearly so; skull conical; the upper part of 
the nose rounded; palate narrow. Svs. 
Sus scrofa, Sus indicus, Sus vittatus. 
2. Face deeply and symmetrically furrowed ; the skull flattened 
on the forehead ; the upper part of the nose flattened, keeled on the 
sides; palate broad. CrnrTuRiosus, 
Sus pliciceps. 
I regard the facts contained in this paper as very interesting—first, 
as adding a new kind of domestic animal to our list (and I do not 
think that any has been added since the introduction of the Turkey 
from Mexico); and secondly, as showing, from a domestic animal, that 
there must be a wild species which has not yet been brought into our 
catalogues. 
I may observe that, like many other very distinct species of cer- 
tain genera of domesticated or semi-domesticated Mammalia, as the 
Horse, Ass, and Zebra, the Ox, the Dog, &c., the fact of inter- 
breeding is no proof that a kind is not a species; for no one would 
argue that an Ass and a Horse are the same species, or a Zebra 
and Quagga, or vice versa. 
The Japanese Pig breeds with facility with the common domestic 
Pig. We have not had time to observe whether the offspring is 
prolific. The half-breed of the Japanese Boar with a common Sow 
retains almost all the external characters of the male parent well de- 
veloped. I have not yet had the opportunity of observing what 
effect the crossing has on the osteological characters of the species. 
I think that no one who will take the trouble to compare the 
skulls of the different varieties of domestic Pigs which are usually 
found in England, with the skull of the European Wild Boars and 
the Wild Pigs of Asia and the Island, can doubt for a moment the 
derivation of the domestic breeds from the wild type*. Indeed, the 
change in form is so slight as to be scarcely perceptible, and the 
gradation between the most abnormal form to the wild animal so gra- 
dual as to be sufficient to show that even the most abnormal state is 
due only to a gradual change of form. 
Mr. Eyton, in a paper printed in the ‘ Proceedings,’ has shown that 
a Chinese Pig which he examined had a different number of vertebrae 
from another domestic Pig; but the skull of a Chinese Pig I have 
examined shows no characters to separate it from the Common Pig. 
Its head is a little shorter than usual, but not so short as that of a 
Berkshire Pig. 
* See Bartlett, Proc. Zool. Soc. 1861, pp. 263, 264; Ann. and Mag. N. H, 
1861, 501; 1862, 162. 
Proc. Zoou. Soc.—1862, No. II. 
