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BRITISH RODEKTS. 

 Bt JAMES RANKIN, Esq. 



G&KTLEMEN — The following paper on British Eodents is intended to some 

 extent to be a companion paper to those which I have already read to 

 this Society on British Cheiroptera and British Insectivora. 



The Order of Mammals, wUch is called Rodentia, consists for the most 

 part of small animals, and its chief and leading characteristic, by which it 

 may at once be distinguished from every other Order of Mammals, is the 

 possession of two prominent incisor teeth in both upper and lower jaws, and 

 by the absence of canine teeth. 



The molar teeth, or grinders, are generally few in number, rarely more 

 than four in each jaw, and fitted for the purpose of grinding and triturating a 

 vegetable diet. 



The external form of many of the animals comprised in this order 

 resembles very much that of those in the order of Insectivora, as, for 

 example, the mouse and the shrew, the porcupine and the hedgehog, and 

 others, the former of each of these two examples being in the Order Rodentia, 

 and the latter in the Order Insectivora. It is only nececessary, however, to 

 examine the dentition of these animals, and it will at once be seen how 

 entirely dissimilar must be their mode of life and kind of food, the Insectivora 

 being provided with nimierous sharp-pointed teeth intended for devouring 

 insects, and the Rodentia having teeth intended for a vegetable diet. 



The Order Rodentia, therefore, comprises only vegetable feeders, if we 

 except some instances of the carnivorous propensities of the rat ; and, like 

 most other vegetable feeders, they are not a bold or pugnacious order of 

 animals, but trust for their safety chiefly to flight. Although mostly small 

 animals, they are very swift of foot and possess great muscular power. 



Most of the order, like the rabbit, rat, mouse, and others, live in holes 

 burrowed in the ground ; and some. Like the beaver, make very perfect and 

 complex dweUings ; some animals in the order, however, like the hare, seem 

 to have lost the instinct of burrowing. 



All the animals comprised in this order are clothed with soft fur, with 

 the exception of the porcupines, which are provided with horny quills over a 

 great portion of the body. In the case of some of the foreign members of 

 this order, as, for example, the chinchillas, the fur is of considerable value. 



The viscera and muscular system of the Rodentia present upon the whole 



