OEDEE OF EODENTIA. 443 



Rat, the Barbary Rat, and the Alexandrian Rat ; in Asia, the 

 Giant Rat, the Caraco Rat, and the Perchal Rat ; in Australia, the 

 Hydromys or Aquatic Rat, which is about the size of the Brown 

 Rat, and lives in the water ; in America, the Brazilian Rat, and 

 the Muscary Rat, larger than the Brown Rat, which occasions 

 immense havoc in the plantations in the "West Indies. 



The Field-Mouse Genus. — In contradistinction to the preceding 

 genus, which have, generally speaking, the tail bare, and as long 

 as the body, this appendage in the Field-Mouse genus is much 

 shorter and hairy. This is the only important characteristic 

 distinguishing the two genera. 



Among this genus may be found some very interesting, but 

 also very mischievous species. As they make their abode in the 

 woods and fields, and, besides, breed with prodigious rapidity, 

 they sometimes become a serious plague to agriculture, and farmers 

 do their best to exterminate them. 



The Common or Small Field-Mouse (Fig. 182) is found all 

 over Europe, except in Italy ; it is also met with in Siberia. 

 It is about the size of the Common Mouse, and makes its abode in 

 some raised bank, where it hollows out irregular passages, all 

 meeting in one chamber. In this hole, on a bed of dry grass, 

 the female gives birth to from eight to twelve little ones three 

 or four times a year. We may judge by this how rapidly 

 they multiply, and the extent of destruction to agricultural pro- 

 duce which results from them. Whole districts have been 

 reduced to destitution by this scourge. In 1816 and 1817 the 

 one department of La Vendee experienced a loss estimated at 

 £120,000, caused entirely by these animals. They were ulti- 

 mately got rid of by poison. 



The Economic Mouse differs but little from the species just 

 named, except that it is larger. It is a native of Siberia, between 

 Daouria and Kamtschatka. The name which is given it alludes to 

 one of its characteristic habits — that of hoarding up, during the 

 fine weather, provisions for the winter. The labours and foresight 

 of this puny creature are a constant source of admiration to the 

 lovers of nature. Its domicile is of a somewhat complicated 

 character, consisting of a principal chamber twelve inches in 

 diameter, and about four inches high, from whence spring numerous 

 Little tunnels tending in every direction, and communicating with 



