Mouse, the common name of the smaller members of the rodent subfamily murium. This subfamily is characterized by incisors smooth in front and compressed laterally; molars 3-3 or -2-2. rooted, the anterior the largest; the ante-orbital foramen a deep narrow slit, widening above; palate mostly on one plane; the descending branch of the lower jaw has n<>t the angles above the plane of the crowns of the molars; other characters in the palate and lower jaw sufficiently distinguish them from anicolince or meadow mice; feet usually naked beneath; the hind legs the longest and five-toed, the anterior with only four and a kind of a wart for a thumb; clavicles complete: tail scaly, with hairs between the whorls of the scales. They hold their food in the fore paws, and sit on their haunches to eat it; most of them burrow and swim well. Reserving the larger species for the article Rat, this subfamily may be subdivided into two principal groups: mures, confined in the wild state entirely to the old world; and sigmodontcs, exclusively American. The former have very large and broad molars, with three tubercles in each transverse series of the upper jaw; the latter have narrower molars, with two tubercles in each similar series.

A third group, merionides, intermediate to the above, with plane molars and transverse complete lamellaa, is found in Africa and central Asia. - In the murine group of this subfamily, the genus mus (Linn.) has the molars of opposite sides parallel to each other, no cheek pouches, the upper lip divided, the whiskers in live series, the nose sharp and hairy to the cleft, and the large, prominent ears nearly naked; the nails are short, pointed and curved; palms naked, with live small balls, those of the hind feet the largest; the hair is soft and line; the mamma) are ten, three pairs on the r abdomen and two pairs on the chest. More than 50 species are described, including the house rats the only one here called a mouse is the common little creature, of our houses (M. musculus, Linn.). This varies much in color, from almost black to pure white; the albino or white mice are a mere variety of the common animals, but have the ability of propagating their race inter sc. "Singing mice " do not differ in appearance from ordinary mice, but make, especially at night, a whistling noise somewhat like the feeble chirp of a canary bird.

The house mouse was originally a native of Europe and central Asia, but is now spread over most inhabited regions of the world; in some parts of the United States, and particularly in newly settled districts, it is replaced by the white-footed mouse, which commits about as much mischief in houses and out-buildings as the common mouse. Of European field mice may be mentioned the M. sylvaticus (Linn.), or wood mouse, found in fields and gardens, where it makes large deposits of provisions in subterranean burrows, laying up grain, nuts, acorns, etc, for winter use. It is smaller than the house mouse, reddish gray above, and white below; the hind legs are so long that it moves by jumps, making the transition to me-riones (111.). The harvest mouse (M. minutus, Pall.; 31. messorius, Shaw) is only 2¼ in. from end of nose to root of tail, this being about 2 in. more. These tiny mice make nests of leaves and straws among standing corn and in thistles, and arc often carried into barns with the harvest, where they live and multiply; in winter they retire to burrows and corn ricks; the color is ruddy above and white below.

The lineated mouse (M. pumilio, Gmel.), from the Cape of Good Hope, weighs less than four scruples (80 grains). Some mice of the genus dendromys (Smith) live on trees; the upper incisors are grooved, the fore feet three-toed with a thumb-like wart, and the long tail is thinly haired and ringed; here belongs the M. mesomelas (Licht.). - Among the American or sigmodont mico arc the genera reithroelon (Waterh.) and hesperomys (Waterh.). Ncotoma and sigmodon belong properly among the rats on account of the large size of all their species. In reithrodon the ears and tail are short and hairy, and the upper incisors are grooved longitudinally in front; three species of ratlike size have been found in the extreme southern portion of South America, while the North American ones resemble slender house mice; the body is depressed, limbs short, head broad and short, tail about as long as the body, thumb rudimentary and with a short nail, and heel hairy; the North American species are found in the southern states on the Atlantic border, and from St. Louis to the Pacific. The harvest mouse (R. humilis, Baird) is about 2¼ in. long, with the tail a trifle less; in color and general appearance it so nearly resembles a small house mouse, that it can only be distinguished at the first glance by the grooved incisors; the eyes are small; it is rarely injurious to the farmer, preferring grass lands to grain fields for its habitation.

In hesperomys or the vesper mice, the typical species have long tails scantily haired, large ears, the quick motions of the common mouse, and generally white feet and a whitish tail. The old genus was of very great extent, embracing a large portion of the American muridoe; the South American species, most of them too large to be considered mice, have been arranged by Burmeister under the genera calomys, habro-thrix, and oxymicterus, established by Water-house, the first resembling the common mouse, the second the meadow mice (arvicokoe), and the third the lemmings. Baird divides even the North American species into three groups, as follows: hesjieromys (Waterh.), containing 13 species; onychomys (Baird) and oryzomys (Baird), each with a single species. In hespe-romys the form is mouse-like, tail not less or even longer than the body without the head, claws weak, hind legs and feet long, and soles naked or less than half hairy. The white-footed or deer mouse (II. leucopus, Le Conte) is between 3 and 4 in. long, with tail about the same; the color of the adult is yellowish brown above, darker on the back, the lower parts of the body and tail and the upper surface of the feet white; the young are dark slaty; the eyes and ears are large, and the fur long and soft.

It is distributed from Nova Scotia to Virginia, and as far west as the Mississippi, and is a common inhabitant of houses and barns; it is nocturnal in its habits, as active as a squirrel, nesting in trees, in the fields, in barns and houses, and making a dwelling resembling a bird's nest; it feeds principally on grain, seeds, nuts, and acorns, and is very fond of maize; it produces two or three broods in a season, according to latitude, five or six at a birth; it is not very injurious to the farmer, most of the mischief commonly attributed to it being due to the arvicoloe or meadow mice; great numbers are destroyed by the smaller carnivorous mammals and birds. Allied species are found in Texas, California, the southern states, and on the Pacific coast. The cotton mouse (H. gossypinus, Le Conte) makes its nest under logs and in trees, often robbing the planter of more than a pound of cotton for a single nest. The hamster mouse (H. myoides, Gapper) is mentioned under Hamster. The prairie mouse (II. Michiganensis, Wagner) is 3½ in. long, with a tail of 1½ in., and the smallest of the genus; the color is grayish brown above, whitish beneath, with the cheeks yellow.

The Missouri mouse (H. leucogaster, Pr. Max.), the type of the group onycliomys, has the clumsy form of the arvicola, tail less than half the head and body, claws large and fossorial, the posterior two thirds of the soles densely furred, and the skull without crest; the body is 4 in. long and the tail 3½ in.; grayish brown above, passing into yellowish red and fulvous on the sides; feet and under surface of body and tail white; the eyes are large, the ears rather short, and the whiskers long; it lives on the seeds and roots of wild plants, and sometimes on corn. The rice-field mouse (H. palustris, Wag.), the type of oryzomys of Baird, has a rat-like form, ears nearly buried in the fur, coarse hair, tail longer than head and body, hind feet long, soles naked, and upper margin of the orbit raised into a compressed crest; it is more than 5 in. long, and the tail about the same; the color is rusty brown above and whitish below. It is found in the rice fields of Carolina and Georgia, burrowing in the dams just above the water line; it scratches up the newly planted rice, eats it in the milky state, and gleans it from the fields in autumn; it is a good swimmer and diver; it eats also seeds of marsh grasses, and small mollusks and crustaceans.

House Mouse (Mus Musculus).

House Mouse (Mus musculus).

Nest and Head of Harvest Mouse.

Nest and Head of Harvest Mouse.

Deer Mouse (Hesperornys leucopus).

Deer Mouse (Hesperornys leucopus).