521 PHILOSOPHY OF ZOOLOGY. 



air was 66. Hence he considers it as the most lethargic of 

 animals. 



The marmot (Arctomys marmota) possesses a summer 

 temperature of 101 or 102, which is gradually reduced in 

 the torpid season to 43, and even lower. 



Bats have a temperature in summer nearly equal to that 

 of marmots. They are soon affected by the changes of 

 the atmosphere, and they cease to respire in a medium of 

 43. In the month of July, the thermometer standing at 

 80, the internal temperature of a bat was 101, which is 

 just the degree of heat in a group of them collected toge- 

 ther in summer, and may therefore be considered as the 

 natural standard. Mr CORNISH applied a thermometer to 

 a torpid bat, and found that it indicated 36. When 

 awakened so much that it could fly a little, he again appli- 

 ed the thermometer, and it indicated 38. SPALLANZANI 

 found a bat, after being exposed during an hour to a tem- 

 perature of 43, to indicate 47, the bulb of the thermometer 

 being placed in the chest ; when exposed to a temperature 

 below the freezing point, the heat of the animal became the 

 same as the surrounding medium, yet it always remained 

 internally higher than the low temperature produced arti- 

 ficially, though the skin did not indicate any difference. 



The wood-mouse (Mus sylvaticus) became torpid, ac- 

 cording to SPALLANZANI, when the thermometer in its 

 cage stood at 43. The temperature of the belly external- 

 ly was 45, but its internal temperature was not much di- 

 minished, even by a degree of cold sufficient to induce 

 torpidity. 



In these experiments we observe, that the temperature 

 of hybernating quadrupeds is greatly reduced below the 

 summer standard, or the ordinary temperature of the 

 animal in health and activity. Still, however, they conti- 

 nue to maintain a superiority in point of temperature above 



