distinguished by decided external characteristics. It would he intoresting and important to know, whether the numerical ratio of the vertebræ, as given in the foregoing table, is constant in each race; and also whether the same variation does not obtain among others of our domestic animals, divided into numerous breeds or races, as the dog, the sheep, and the goat. The subject has not been treated so fully and extensively as it deserves. With respect to the caudal vertebræ, indeed, we know that they are subject to great numerical variation in most of our domestic animals; witness the dog and even the common fowl, of which latter, a tailless breed, perpetuated from generation to generation, is far from being uncommon. What takes place in one part of the spinal column may, we conceive, occur also in another and more important portion, to some, if not to so great an extent; and the modification may moreover be transmitted from one generation to another.
Examples of extraordinary modification in other parts of the skeleton, transmissible from generation to generation, may be here adduced in confirmation of our views. Aristotle notices a race of hogs with undivided toes, or rather with hoofs consolidated together; and Linnæus informs us that a similar variety of the hog is not unfrequent in the neighborhood of Upsal, in Sweden. A still more extraordinary case of modification of the osseous framework, is recorded in the Proceedings of the Zoological Society for 1833, p. 16, where will be found the notice of a race of pigs with only two legs, the hinder extremities being entirely wanting. The communication, with drawings of two individuals, was made by Colonel Hallam, who states that these animals were observed "at a town on the coast in the Tanjore country, in the year 1795; they were from a father and mother of a similar make, and the pigs bred from them were the same." Thus, then, accidental malformations, either by excess or deficiency, may become transmissible, and so perpetuate themselves.
The views of a writer in the Penny Cyclopædia, on the subject of the osteological differences observable in domestic swine, are much in accordance with our own. Undoubtedly, he remarks, such records as those given by Mr. Eyton are valuable, but he thinks that the inference is precipitate; adding, that John Hunter's theories are not so easily done away with, and that osteological character will continue to be a criterion of species, notwithstanding the differences set forth. He says, "By the term pig, we understand the African and Chinese varieties of the hog. Phacochœrus cannot be meant, or it would be stated. The pure Chinese breed was imported long ago; and for years its stock, bred from its union with our English varieties, has been known in our farm-yards. The varieties bred by man from the wild hog, are spread all over the world in a domesticated state; and there is no more reason to doubt that the
