MUS. 
M. kmnins, or the leining. Tliese ani- 
mals are sometimes five inches long in the 
body, and in some countries (as Siberia) 
only three. They abound in the mountain- 
ous districts of Norway and Lapland. In 
their general habits they are by no means 
particularly social ; but reside in a dispersed 
manner, without skilfully contrived habita- 
tions, or storing Up in magazines. On cer- 
tain occasions, however, they descend from 
their elevated situations into the plains, in 
innumerable and formidable imiltitudos. 
Their direction is always in a straight line, 
from which nothing induces them to deviate 
but the absolute impossibility of proceeding 
in it. Their track is visible by the destruc- 
tion ofnerbage- which attends it, the grass 
being devoured to its extreme roots, and 
their course exhibiting, instead of the 
greenness of vegetation, the brownness 
ef a fallow'. These migrations happen at 
irregular periods, generally after an inter- 
val of some years, and the perseverance and 
intrepidity with which they are cottdiicted 
are matter of astonishment. If attacked by 
men, they will spring at the legs of the as- 
sailants, and with great ditRcnlty can be 
made to quit their hold. Thoasauds are 
destroyed in these progresses by birds of 
prey, and often the most formidable and 
fatal conflicts occur among themselves. 
M. oeconomus, or tlie teconomic rat, re- 
sembles the Icming in the circumstance of 
irregular migrations. These are met with, 
particularly in Siberia, burrowing with the 
greatest skill, and forming considerable 
magazines of provisions (chiefly various 
plants) for their winter consumption, and 
wliich they occasionally produce, if damp, 
to dry them perfectly in the snn. They are 
about five incites and a quarter in their 
whole length. In their migrations they swim 
over rapid rivers, preserving a' course direct- 
ly to the west, and experiencing extreme 
fatigue and peril, to which immense num- 
bers of tliem become victims. A single 
party has been seen so numerous, as to take 
tw o hours in passing before the astonisiu’d 
■spectator. Scarcity of food is supposed tlid 
grand impulse to these progresses. Tlie 
inhabitants of Kamtschatka are said to 
fob the hoards of these animals in winter, 
pretending to make compensation by leav- 
ing some childish toy behind. 
M. cricetns, or the hamster, is a species 
of file pouched rats, and the sole European 
species of that description. The pouches 
are one on eacli side of tlie month, and, 
when filled, are like two blown bladders. 
Tliese animals are found in Poland* and' 
Russia, and are extremely ininrions, by tlie 
quantities of grain which tliey devour, and 
also carry oft' for their aiituinnal store in 
their enrions pouches. They are liighly 
curious in the structure of tlieir habitations. 
Tlie females arrange their mansions difter- 
ently from tlie males, and are stated never 
to reside w ith them. As winter approaches 
they seclude tliemselves completely, and 
enjoy their stores, wliich are generally con- 
sumed when winter reigns in fiill rigoiu', 
about which lime tliey roll the.mselves up, 
and continue till spring in a .'itatc of pro- 
found slumber, or torpor. Their bodies 
are then said to be perfectly cold, and their 
limbs stiffened, and they may be opened 
witliont awaking them. The heart is seen 
to beat in them fifteen times in a mimite, 
wliile in the summer its pulsations are 150 
in the same time. The fat is said to be co- 
agulated, and the intestines exhibit no ex- 
citability by the most stimulating applica- 
tions. The waking of the hamsters from 
their leiigtliciied sleep is a very gradual 
process, occupying sometimes no less tlian 
two horns. These animals are unsocial, 
fierce, ami malignant. Tiiey attack every 
weaker creature, and very frequently de- 
stroy each other. 
M. miisculiis, or the common mouse, in- 
habits almost every part of the world, is 
shy and timid, but not ferocious in its tem- 
per. It produces generally from six to ten 
at a birth, and breeds several times in the 
course of a year. Its skin is sleek, and its 
ej'es are brialit and lively; its limbs are 
neatly formed, and its movements are ex- 
tremely agile. It is occasionally seen of 
perfect whiteness, and its appearance then 
is beautifnl and interesting. It haunts the 
habitations of man, from which it is scarcely 
ever fonnd at any considerable distance, 
and in which it commits no trifling depre- 
dation. 
M. sylvaticus, or the long-tailed field 
mouse, is somewlmt larger than the former, 
and of a yellowish-brown colour. It feeds oil 
acorns, fruits, and grain, and lays up maga- 
zines in its burrowed mansion for tlie win- 
ter. It is found princiimlly in dry grounds ; 
is common in all the temperate regions of 
Europe, and is particularly abundant and 
destructive in France, where it is stated to 
commit more waste and liavock than are ef- 
fected hyall otlier quadrupeds, and birdsalso. 
Under a scarcity of the usual supplies, these 
aniitials are supposed to destroy each olhet'. 
Their stores in fruitfal veal's are astonislr- 
