HUDSON 



EAGAN: Do these animals shiver as they are coming out of 

 torpor? 



HUDSON; Yes. The magnitude of the shivering tends to vary 

 from one individual to the next, but there seems to be no difference 

 in rate of arousal correlated with this. One gets almost the impres- 

 sion that there is some inefficient use of shivering going on in some 

 individuals . 



EAGAN: I think this could explain the higher metabolism. Be- 

 cause after all, when the animal is completely back to body tem- 

 perature, then it does cease its shivering. 



HUDSON; This would be the explanation for the actual heat 

 production itself. 



EAGAN; And the overshoot? 



HUDSON; Yes. Shivering of course will continue on beyond the 

 overshoot. 



JOHANSEN: Have you tried to look for any vascular changes 

 in the legs by measuring superficial temperatures? 



HUDSON: No, we have not. 



HANNON: Has there been any measurement of changes in blood 

 chemistry during the course of torpor? I am getting back to this 

 increase in oxygen consumption, and particularly, I would think 

 of lactic acid. Is there an accumulation of lactic acid? 



HUDSON: I do not know. The intubation technique that Lyman 

 has extended promises to be a good means for finding this kind 

 of information.* 



*Lyman, Charles P. and Regina C. O'Brien. 1960. Circulatory changes in the 

 thirteen- lined ground squirrel during the hibernating cyde. Bull . Mus . Cornp. Zool . 

 124:353-372. 



452 



