EODENTIA. 



condition of the brain, and by other points, is at a low 

 par, and the ratio of their intelligence is in a parallel de- 

 gree. We may tame them, but we cannot educate them. 

 They are all timid and feeble, and trust for self-protec- 

 tion to flight or concealment. The prey of ferocious 

 beasts and birds and reptiles, their fertility, by a wise 

 provision, counterbalances their annual diminution. 

 Spread over the earth, from the equator to the coldest 

 latitudes, they tenant rocks and mountains, plains and 

 woods, feeding on grain and vegetables, and often de- 

 vastating the cultivated domains of man. To a vegetable 

 diet some few, as the rat, add animal food also. Most 

 are nocturnal or crepuscular in their habits ; many dwell 

 in burrows, some conceal themselves amidst herbage, 

 some amongst the foliage of trees, and some build for 

 themselves habitations which have excited the interest 

 and admiration of man. 



In noticing the numerical abundance of the Rodentia, 

 throughout the different quarters of the globe, it should 

 be observed that in Australia six or eight species are all 

 that we are acquainted with belonging to that region ; 

 Europe, North America, and South America are nearly 

 equal as to the number of species they contain. India and 

 Africa are also nearly equal, but they contain fewer 

 species than either of the other provinces. The squir- 

 rels, rats, porcupines, and hares are the only groups 

 found in all the provinces ; all the rest of the groups 

 are respectively confined to their own particular geogra- 

 phical province. The naturalist will find some import- 

 ant observations on the Rodentia by Mr. Waterhouse, 

 in the ' Zool. Proceeds.,' for 1839; in the ' Zool. of the 

 Voyage of H.M.S. Beagle;' and in the 'Mag. of Nat. 

 Hist,' New Series, 1839, p. 90. 



THE SQUIRRELS (Family Sciundce). 



These elegant animals are found in every quarter of the 

 world, Australia excepted. The general characters of 

 the true squirrels (Sciurus), as exhibited by our well- 

 known British species, are familiar to all : its fine full 



