TORPIDITY. 57 



only fourteen beats have been distinctly counted, and those 

 at unequal intervals. 



Dormice, when awake and jumping about, breathe so 

 rapidly, that it is almost impossible to count their pulse ; 

 but as soon as they begin to grow torpid, eighty-eight pul- 

 sations may be counted in a minute, thirty-one when they 

 are half torpid, and only twenty, nineteen, and even six- 

 teen, when their torpor is not so great as to render the ac- 

 tion of the heart imperceptible. 



Spallanzani and others are of opinion, that the circu- 

 lation of the blood is entirely stopped in the remote 

 branches of the arteries and veins, and only proceeds in 

 the trunks of the larger vessels, and near the heart. But 

 it is probable, that howeyer languid the circulation may be, 

 it is still carried on, as the blood continues fluid. He found, 

 that if the blood of marmots be subjected, out of the 

 body, to a temperature even higher than that to which it 

 is exposed in the lungs of these animals, it is instantly fro- 

 zen ; but it is never congealed in their dormant state. 



4. Diminished Irritability. — The irritability of torpid 

 animals, or their susceptibility of being excited to action, 

 is extremely feeble, and in many cases is nearly suspended. 

 Destined to remain for a stated period in this lethargic 

 state, a continuance of their power of irritability would be 

 accompanied with the most pernicious consequences ; as 

 thereby they would be often raised prematurely into ac- 

 tion, under a temperature which they could not sup- 

 port, and at a time when a seasonable supply of food 

 could not be obtained. In their torpid state, therefore, 

 they are not readily acted upon by those stimuli, which 

 easily excite them to action, during the period of their 

 activity. Parts of their limbs may be cut off, with- 

 out the animal shewing any signs of feeling. Little ac- 

 tion is excited even when their vital parts are laid open. 

 When the hamster is dissected in this torpid state, the in- 



