ORDER RODENTIA. 121 



intense cold than this accelerates the circulation, and con- 

 sequently the respiration, and even revives the animal to 

 activity. 



M. Mangili's hypothesis, as to the cause of certain quad- 

 rupeds hybernating, seems to be, that the arterial blood ne- 

 cessary to excite and revive the fibres ©f the cerebral organ, 

 flows less copiously to this organ in the hybernating animals 

 on account of the small number of the arteries he had found 

 in such animals, and of the smallness of their calibre ; this 

 concurring with other exterior causes of debility, diminishes 

 the energy of the fibres of the brain, and produces at first 

 sleep, and eventually, continued lethargy. 



The same physiologist took a Loir about midsummer, 

 when the temperature was at 15 or 16°, and put it at 

 the bottom of a large vase, with a bed of hay and provisions. 

 The animal after having tried in vain to escape refused its 

 food, and quickly fell into a state of lethargy ; but, instead 

 of previously rolling itself into a ball, it stretched itself on 

 the back. In this state the intervals of repose were much 

 shorter than in winter, and the respiration was less fre- 

 quent. It did not wake till the 17th of July, when it 

 effected its escape. 



The Fat Dormouse is not extensively located, being 

 confined to the temperate parts of the continent of Europe, 

 but not on the high mountains where the Marmot is 

 found. 



This species is still used for food in Italy, and is taken 

 simply by preparing a fit place for its winter quarters in the 

 wood, which is large enough for many of them to retire to, 

 whence they are taken toward the end of Autumn. The 

 Romans were very fond of them as food ; they kept and 

 fattened them for the table in receptacles called Gliraria. 

 Martial tells us that they are fattest after hybernating, 

 when they have had nothing but sleep to fatten on ; on 

 which Buffon observes, that the Loir, at all times fat, keeps 



