358 
DR. MARSHALL HALL ON HYBERNATION. 
hour; the thermometer at the diaphragm was 87°; in the pelvis 83°; but the 
animal was now less lively. 
“ Having been put into its cage, the thermometer being placed at the dia¬ 
phragm, in two hours afterwards, was at 93° 
In these experiments the animals appear to have been roused partly by the 
state of the wound in the abdomen, but chiefly by the extreme cold. They 
can scarcely, however, be considered as experiments upon hybernation, how¬ 
ever interesting they may be in reference to reviviscence from that state. 
The fact of the fatal influence of excited respiration during the augmented 
irritability of hybernation, contrasted with the similar fatal effect of suspended 
respiration, during the diminished irritability of the state of activity, will 
illustrate many of the causes, kinds, and phenomena of death. Do not these 
resolve themselves, in fact, into irritability insufficiently or excessively excited ? 
Recapitulation. 
The object of this paper has been to treat of the singular phenomena of hy¬ 
bernation, and especially to point out the remarkable application of the law 
stated in my former paper, to the active and lethargic states of the hybernating 
animal. 
1. The natural sleep of the hybernating animal differs greatly, yet only in 
degree, from the sleep of any other animal. 
2. This sleep passes insensibly into the state of true hybernation, which is 
more profound, as the blood loses its arterial character; for 
3. In hybernation, the respiration and the evolution of heat are nearly sus¬ 
pended. 
4. The irritability is, at the same time, singularly augmented ; and the ani¬ 
mal bears proportionately the privation of air. 
5. The nervous sensibility and the muscular motility are unimpaired. 
6. There is the singular phenomenon of this unimpaired sensibility, and the 
capability of bearing the privation of air without pain; a fact which receives an 
interesting and perfect explanation from the additional fact of the augmented 
irritability or veno-contractility of the left side of the heart. 
* Animal (Economy, pp. 11], 112. 
