MURRAYA, in botany, so named in honour of Joseph Andrew Murray, pro fessor of medicine and botany at Gottin gen, a genus of the Decandria Monogynia class and order. Natural order of Auran tia, Jussieu. Essential character : calyx five-parted; corolla bell shaped, with a nectary encircling the germ : berry one. seeded. There is but one species ; nix. M. exotica, ash-leaved Murraya, a native of the East Indies.
MUS, the rat, in natural history, a ge nus of Mammalia of the order Glires. Generic character : fore-teeth, upper, wedge-formed : three grinders almost al ways each side each jaw ; clavicles in the skeletons. There are forty-six species, of which we shall notice the following: M. zibethicus, or the musk rat, is as large as a small rabbit, and very common in Canada; and resembles the beaver in the shape of its body, and in its instincts and character. It lives in society, and constructs its habitation with great skill and art, about two feet in diameter, and stuccoed within with particular neatness, on the border of some lake or stream. On the outside it is covered with a matting of rushes, compacted with great close. ness, to preclude moisture. These ani mals live on roots and herbage, which, however, they do not store up in their houses, but make excursions for, as they are demanded during the winter ; in sum mer, they make long progresses in pairs. They have attached to them a strong odour of musk ; and walk and run with great awkwardness ; are easily tamed, and highly valued for their fur.
M. decumanus, or the Norway rat, is imagined to have been imported into Eu rope from India, and in this country has almost extirpated the animals known by the name of black rats, which formerly universally abounded in it. It subsists not only on grain and fruits, but frequent. ly attacks poultry and rabbits, as well as various other animals. It is about nine inches long in the body, and nine more in the tail ; will swim with considerable ease ; is in the highest degree prolific, producing occasionally even eighteen young at a time, and breeding not unfre quently three times a year. It is bold,
fierce, and voracious. When closely fol lowed, it turns on its enemy, and fastens on him with its sharp and irregular teeth, inflicting a wound which it requires con siderable time to heal. The depredations committed by these animals are calculat ed at an almost incredible amount. Their extreme fecundity, and their means of eluding the hostility of man in a thousand instances, render them one of the most serious nuisances. They plunder pigeon houses, granaries, warehouses, and every species of stores convertible to food, with incessant rapacity and perseverance. They carry off sometimes considerable quantities of grain, and store it in their holes. They wage, however, most dread ful war on one another, and the weak be come uniformly the victims of the strong. The large male rat, which generally lives in a mischievous and malignant solitude, is the most fatal enemy to his species. Dogs, cats, and weasels, combine their ef forts with those of man to produce their extirpation ; but nothing appears capable of counteracting their rapid multiplica tion, and producing security from one of the most predatory and annoying ani mals which infests the society of man kind. Their sagacity is very extraordi nary; and snares laid for them, after one victim has been known to fall by them, are generally laid in vain. The surest method of destroying them is by mixing poison with some favourite food, snd lay ing it in their way. See Mammalia, Plate IX. fig. 4.
M. rattus, or the black rat, is consider ably smaller than the former, and in the populated part of this country has been neatly annihilated by it. Its habits are almost precisely similar to those of the former. It is reported by travellers, that in various parts of Germany it is sometimes taken and domesticated, and having a bell put round its neck, is thus almost invariably found to alarm all others of it species from the vicinity.