THE BROWN RAT 
THE BROWN RAT 
Mus decumanus, Pallas. 
Plate 30. 
The Brown or Common Rat, known also as ' Norway Rat ' and 
' Hanoverian Rat ' is too familiar to require much description, and 
is distinguished from the Black Rat by its stouter form, rounder 
head and muzzle, smaller ears, and comparatively short and more 
scaly tail. The whiskers are also less plentiful and not so long. 
The colour above is a tawny greyish brown, darkened with 
numerous black hairs along the ridge of the back, the under parts 
are dull white. Full grown specimens vary much in size, but they 
often attain a length of 9 inches in the head and body, and j{ 
inches in the tail. 
An exceptionally large example examined by Mr. Millais in Sussex 
had a total length from nose to tip of tail of 19I inches, and 
another has been recorded of 23 inches. 
The original habitat of this species, like that of the Black Rat, 
is uncertain, but the more temperate parts of Siberia are considered 
to have been an ancient nursery of the race. 
According to Pallas the species moved westwards in hordes in 
1727. Invading Russia and other neighbouring countries, it appeared 
in England before 1730, where it soon settled down and rapidly 
increased in numbers, but did not reach Scotland till after 1764. 
No other animal is so deservedly unpopular as the Common Rat. 
Universally hated and with every man's hand against it, it never- 
theless contrives to exist and increase in numbers in spite of all 
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