many species known popularly as Weasels, Ermines, Stoats, Ferrets, Polecats, Minks, and Vison. Not only is the genus common to both Old and New Worlds, but in a few cases the species (e.g. P. erminea) range from Asia to America. The molar formula is Pm 3/3 M 1/2. The form of the body is an exaggerated one, the length of the trunk to the limbs being very great. The feet are more or less hairy beneath, and the animals are digitigrade. The nose is grooved. The dorsal vertebrae vary from thirteen to sixteen.
Fig. 221.—Polecat. Mustela putorius. × 1⁄6.
There are four British representatives of this genus:—
The Polecat, P. foetidus, is a dark brown-coloured animal. Its total length is about 2 feet, of which the tail occupies some 7 inches. It is a species banned by the gamekeeper, and hence is approaching extinction in this country. It is excessively bloodthirsty, as are apparently all the members of this genus, and kills out of mere wantonness. The Ferret is simply a domesticated variety of the Polecat.
The Stoat or Ermine, P. erminea, is reddish brown above, white beneath. In winter, in certain localities, it becomes white with the exception of the black tip of the tail. This colour-change bears some relation to the degree of latitude. It is universal in the north of Scotland, rare in the south of England. As is the case with some other animals that generally change
