XATURAL HISTORY. 257 



THE FAT SQUIRREL. 



OF this'animal we know three species; namely, the 

 Fat squirrel, the garden squirrel and the dormouse. Many 

 authors have confounded these species together, though 

 they are all three very different, and of consequence 

 easily known and distinguished. 



The fat squirrel is nearly of the size of the common 

 squirrel, and, like it, its tail is covered with long hair. 

 It is without foundation that these animals have been 

 said to sleep during the winter. They are not in a 

 state of natural sleep at this period. They are in a 

 torpor, which is produced by the coldness of the blood, 

 and by which they lose the use of their members and 

 senses. Their internal heat is indeed so small, that it 

 hardly exceeds that of the temperature of the air. 

 When the heat of the air is at ten degrees above the 

 freezing point of the thermometer, the heat of these 

 animals is also at ten degrees. Now it is well known, 

 that the internal heat of man, and of the most of ani- 

 mals, always exceeds thirty degrees ; there is little 

 reason therefore to wonder that these animals, so in- 

 ferior comparatively to all others in point of heat, 

 should become torpid as soon as their own little quan- 

 tity of internal heat ceases to be assisted by the exter- 

 nal heat of the air. This circumstance, however, na- 

 turally happens when the thermometer is not more than 

 ten or eleven degrees above congelation. This is thereal 

 cause of the torpor of these animals ; a cause of which 

 naturalists have not been apprized, and which, neverthe- 

 less, extends to all animals that sleep during the winter. 



This torpor continues as long as the cause which 

 produces it, continues to operate, and ceases when the 



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