HEMINGWAY, A. 
DISCUSSION 
DR. CLARK: I would rather not ask a question. I would like to 
get into this shive ring pathway because there is some of Dr. Keller's 
work that has been misinterpreted. If I could take a few minutes, I 
would like to go over this. 
If you make a complete transection throu^ the midbrain and 
then put the animal in the cold as indicated by one of Dr. Heming- 
way's diagrams, you are going to get a progressive loss in bocfy 
temperature with time. As you quite well know, when you are 
attempting to make lesions like this, youfailquite frequently. Now, 
say you leave a little bit of the cerebral peduncle. The temperature 
may go way down. These animals shiver; there is a little of the 
cerebral peduncle left. We do not know how the fibers go through 
there; we do not know where they come from; but we are attempting 
to get an anatomical basis for this finding. We have seen it in both 
cat and dog, but when the entire brain stem is transected except 
for a little of the pyramid, there is still shivering. 
DR. STUART: How long after transection were such preparations 
studied? 
DR. CLARK: I think the longest time has been seven or eight 
months. You probably would not see it until the animal is at least two 
months postoperative. 
DR. HEMINGWAY: How much of the other tissue is there, Dr. 
Clark, above the peduncle? None at all? 
DR. CLARK: There is only a part of the peduncle left, and the 
amount that is left determines the rate of cooling. The pathway for 
shivering is more medial than the pathway for panting; part of the 
shivering fibres are in the peduncle. I am not saying they are part 
of the pyramidal tract; I am simply saying that there is something 
resembling shivering after this transection, and that these physio- 
logical observations are confirmed by subsequent studies of sections. 
DR. STUART: If the animal is shivering, how does the body 
temperature fall? 
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