M U S. 
235 
variety of it. It inhabits North America, among (tones 
and clefts remote from habitations; and in fixe, colour, 
&c. feems to agree with the carapo. Mr. Pennant de- 
fcribes it from a fpecimen in the (late) Leverian Mufeum. 
7. Mus rattus, the black rat: tail very long, fcaly; 
body black, beneath cinereous. This fpecies, though 
now common in moll parts of Europe, is fuppofed-to have 
been originally introduced from India and Perfia. The 
word rattus, or rat, is modern: the Romans probably 
comprehended all kinds under the word mus. The Welfh 
cajl it the French moij'e, which intimates that it has been 
imported thence into our ifland. None of them are found 
in Siberia or Kamtfcatka. They fwarm at Otaheite, and 
others of the Society Iflands; and are met v.'ith in New 
Zealand and New Holland. In Otaheite they are fo bold 
as to attack the inhabitants when afleep, who hold them 
in the utmolt deteftation, but will not kill them, left 
they ihould be polluted by the touch : they will not even 
eat the bread-fruit thefe animals happen to run over. 
The rat is fuppofed to be a native of North America, as 
well as of Europe; but it is faid that South America was 
entirely free from it, till it was imported there in (hips 
from Europe, in the year 1554. 
The general length of this original fpecies, from nofe 
to tail, is (even inches, and of the tail eight inches. The 
colour of the head and whole upper part of the body is a 
dark iron or blackidt grey; the belly is of a dull afti-colour: 
the legs are duflcy, and very (lightly covered with hair: 
the fore feet have only four toes, with a fmall claw in 
place of a fifth: the tail is nearly naked, coated with a 
Italy (kin, and marked into numerous divifions or rings. 
This animal breeds frequently, and commonly brings 
about fix or feven young at a time. Sometimes they in- 
creafe fo faft as to overftock the place of their abode; in 
which cafe they fight and devour each other. It is faid 
that this is the reafon why thefe animals, after being 
extremely troublefome, fometimes difappear fuddenly. 
Various are the methods made ufe of for the expulfion of 
rats from the places they frequent; among which none is 
more Angular than-that mentioned by Gefner, wdto tells 
us he had been informed, that, if a rat be caught and a bell 
tied round its neck, and then fet at liberty, it will drive 
away the reft wherever it goes. This expedient appears to 
be occafionally pratlifed in modern times with fuccefs ; in 
confirmation of which, Dr. Shaw relates the following 
ftory. A gentleman, travelling through Mecklenburgh 
about thirty years ago, was witnefs to the following curi¬ 
ous circumftance at the poft-houfe in New Stargard. Af¬ 
ter dinner the landlord placed on the floor a large diflt of 
fioup, and gave a loud whiftle. Immediately there came 
into the room a maftiff, a fine Angora cat, an old raven, 
and a remarkably large rat, with a bell about its neck. 
The four animals went to the di(h, and, without difturb- 
ing each other, fed together; after which the dog, cat, and 
ra't, lay before the fire, while the raven hopped about the 
room. The landlord, after accounting for the familiarity 
which exifted among the animals, informed his gueft that 
the rat was the molt ufeful of the four, for the noife he 
made had completely freed the houle from the rats and 
mice with which it was before infefted. 
( 3 . A very fmall variety of this fpecies, not much larger 
than a moufe, is faid by Dr. Pallas to be found about the 
deferts in the lower parts of the Volga. Like many other 
quadrupeds, the rat is fometimes feen perfettly white, in 
which cafe it has red eyes. The white rat, however, as we 
are allured by Mr. Sell reber, does not always produce young 
ones of a fimilar colour; fo that fuch varieties can hardly 
be confidered as permanent. Thi,s is proved from an ob- 
fervation of profeflor Herman,who, having kepta pregnant 
white rat for fonie time, found that the young ones were 
of the ufual colour of their fpecies. 
8. Mus decumanus, the common grey rat: colour grey, 
(lift-haired, with very long fcaly tail, and body wliitifli be¬ 
neath. This domeftic fpecies, which is now become the 
common rat of our own ifland, and is popularly known 
by the name of the Norway rat, (Pennant’s brown rut,) is 
fiippofed, like the preceding, to be a native of India and 
Perfia, from which countries it has been imported into 
Europe. In England it feems to have made a national 
conqueft over the black rat, which is now become rare in 
comparifon. The grey rat is larger than the black rat, 
meafuring nine inches from the nofe to the tail, which is 
of the fame length, and marked into about two hundred 
rings or circular (paces : the colour is a pale tawny grey, 
wliitifli beneath : the fore feet have four toes, with a claw 
in place of a fifth. It is a bold and voracious animal, and 
commits great havoc in granaries, See. Sometimes it takes 
up its refidence in the banks of waters, and fwims occa¬ 
fionally with almoft as much facility as the water-rat, or 
Mus amphibius. In its general manner of life it agrees 
with the black rat; and not only devours grain and fruits, 
but preys on poultry, rabbits, and various other animals. 
It is a very prolific fpecies, and produces from ten to 
twelve or fourteen, or even fometimes eighteen, young at 
a time. When clofely purlued, it will fometimes turn upon 
its adverfary, and bite with great feverity. It fee-ms to 
have made its firft appearance in England about feventy 
years ago; and is (till much lefs frequent in France and 
fome other parts of the continent than the black rat. In 
France, according to Butfon, it was firft obferved at Chan¬ 
tilly, Marly-la-Ville, and Verfailles, where it committed 
great ravages. This author affirms that it breeds three 
times a-year. The common rat is (liown on the annexed 
Engraving, at fig. 1. 
In Mr. Charles Fothergill’s “ Effay on the Philofophy, 
Study, and Ufe, of Natural Hiftory,” (1813.) we find fome 
beautiful reflections which remind us of Ray and Derham. 
We (hall extract a few paragraphs which relate to the fub- 
je£t we are upon. 
“ Nothing can afford a finer illuftration of the beau¬ 
tiful order and fimplicity of the laws which govern the 
creation, than the certainty, precifion, and regularity, 
with which the natural checks on the fuperabundant in- 
creafe of each tribe of animals are managed ; and every 
family is fubjett to the operation of checks peculiar to 
that fpecies, whatever it may be, eftabliflied by a wife law 
of the Molt High, to counteract the fatal efteCts that might 
a rife from an ever-aftive populative principle: and it is 
by the admirable difpofition of thefe checks, the con¬ 
templation of which is alone fufficient to aftonifli the 
loftieft and mod comprehenfive foul of man, that the 
whole fyllem of animal life, in all its various forms, is 
kept in due ftrength and equilibrium. 
“ This fubjett is worthy of the naturalift’s moft ferious 
confideration, as, by a few hints, I will now attempt to 
(how.” 
Mr. F. then quotes from Mr. Malthus, “ The great 
law of neceffity, which prevents population from increaf- 
ing in any country beyond the food which it can either 
produce or require, is a law fo open to our view, fo obvi¬ 
ous and evident to our underftaudings, that we cannot 
for a moment doubt it.” And afterwards proceeds :— 
“ This great law pervades and affetts the whole animal 
creation, and fo aftive, unwearied, and rapid, is the prin¬ 
ciple of increafe over the means of fubfiftence, amongft 
inferior animals, that it is evident whole genera of car¬ 
nivorous beings amongft beads, birds, fifli, reptiles, and 
infeCts, have been created for the exprefs purpofe of fup- 
prefling the redundancy of others, and reftraining their 
numbers within proper limits. But even thofe checks 
are infufficient to reftrain the eftefts of a too-rapid popu¬ 
lative principle in fome animals, which have, therefore, 
certain deftructive propenfities given to them by the 
Creator, that operates powerfully upon themfelves and 
their offspring, as may be particularly obferved in the 
natural hiftory of the rabbit, but which is (till more evi¬ 
dently and ftrikingly dilplayed in the life and economy 
of the rot. 
“ It has been calculated by Mr. Pennant, and there 
can be no doubt of the truth of the ftatement, that the 
altoni filing 
