SQUIRRELS, BEAVERS, DORMICE, AND RATS 241 



as great a pest as In India (where it carries the plague from place 

 to place) or in England. Its universal extirpation should be 

 made the special object of an International Congress. 



Mus rattus. The Black Rat 



The Black Rat is 2 in. shorter in the body than the brown rat, 

 but the tail is proportionately longer, being 7^ in. in length; as 

 compared with the 7 in. of the body. The tail is very tapering 

 and curly towards the tip. In colour normal specimens are 

 grayish-black above and pale gray below. Occasionally examples 

 are met with that are brownish-gray, and allied forms in Egypt 

 and Tropical Asia tend very much to reddish-gray or chestnut. 

 The fur of the black rat is beautifully fine and soft, and when 

 it was more plentiful the skins were of considerable value in 

 commerce. In an allied form coming from the Andaman Islands, 

 however, the fur actually develops spines. The black rat is the 

 origin of tame albino or pied rats, which must have been in 

 existence as a domesticated breed for at least a couple of hundred 

 years. Like the brown rat, it has twelve mammae, and breeds 

 three or four times in the year, having a large number of young 

 in a litter. It is almost as omnivorous as the brown rat, though 

 perhaps from its less vigorous constitution and greater timidity 

 it is not such a carnivorous animal. The black rat presumably 

 originated in Western or Central Asia, and commenced the 

 invasion of Europe and Africa at a relatively remote period 

 (perhaps 1,500 years ago), travelling, like the brown rat, through 

 Russia and Germany.^ Its introduction into England may date 

 back to the time of the Norman Conquest or earlier. It was 

 called by the Welsh the " French mouse." After a time it 

 inhabited the whole of Europe as far north as Lapland, and 

 southwards into North Africa. The present writer has met 

 with the black rat in Central Africa, in the more isolated 

 villages where it has not yet been extirpated^by its brown relation. 



^ The word "rat" is of Teutonic origin. The Romans did not 

 distinguish this creature by any specific name. If they knew it they called 

 it a mouse. 



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