Ermine, an alternative name for the stoat (Putorius ermineus), apparently applicable in its proper sense only when the animal is in its white winter coat. This animal measures 10 in. in length exclusive of the tail, which is about 4 in. long, and becomes bushy towards the point. The fur in summer is reddish brown above and white beneath, changing in the winter of northern latitudes to snowy whiteness, except at the tip of the tail, which at all seasons is black. In Scottish specimens this change in winter is complete, but in those found in the southern districts of England it is usually only partial, the ermine presenting during winter a piebald appearance. The white colour is evidently protective, enabling the animals to elude the observations of their enemies, and to steal unobserved on their prey. It also retains heat better than a dark covering, and may thus serve to maintain an equable temperature at all seasons within the body. The colour change seems to be due to phagocytes devouring the pigment-bodies of the hair, and not to a moult.
The species is a native of the temperate and subarctic zones of the Old World, and is represented in America by a form which can scarcely be regarded as specifically distinct. It inhabits thickets and stony places, and frequently makes use of the deserted burrows of moles and other underground mammals. Exceedingly sanguinary in disposition, and agile in its movements, it feeds principally on rats, water-rats and rabbits, which it pursues with pertinacity and boldness, hence the name stoat, signifying bold, by which it is commonly known. It takes readily to water, and will even climb trees in pursuit of prey. It is particularly destructive to poultry and game, and has often been known to attack hares, fixing itself to the throat of its victim, and defying all the efforts of the latter to disengage it. The female brings forth five young ones about the beginning of summer. The winter coat of the ermine forms one of the most valuable of commercial furs, and is imported in enormous quantities from Norway, Sweden, Russia and Siberia. It is largely used for muffs and tippets, and as a trimming for state robes, the jet black points of the tails being inserted at regular intervals as an ornament. In the reign of Edward III. the wearing of ermine was restricted to members of the royal family; but it now enters into almost all state robes, the rank and position of the wearer being in many cases indicated by the presence or absence, and the disposition, of the black spots. (See also Fur.)
