ANTERIOR HYPOTHALAMIC LESIONS 
ber this particularly because I am very interested in the phenomena. 
Teagueand Hanson's graph shows rectal temperature against time; 
it shows a period of stress; the temperature will go up, and then it 
will level off. This is my question: how come? Why does it not go 
up to 43 C or 44 C? You see, if they have lost all ability to regu- 
late against heat, they should be unable to control at any level, but 
now they have this cut-off level and they survive. 
DR. CLARK: I know, but that cut-off level is also due to the 
temperature that they are exposed to; when their temperature gets 
above 41 C, they are going to be able to lose heat to the environ- 
ment. 
DR. FREEMAN: Then, they should show some kind of gradual 
approximation to this thing, but this is not what the curve shows, by 
and large. 
MR. ADAMS: How does this approach the peak? Is it as sharp 
as you have shown? 
DR. CLARK: I would have to check back and see the data. One 
time I was told to take a cat's temperature up until it panted, and I 
did; I took his temperature up to, I think it was 44 C, and that was 
rather an acute preparation. In order to get it up that high, 1 had to 
raise the box temperature progressively and so the box temperature 
was way above 40 C when the cat's temperature reached 44 C. 
MR. ADAMS: Dr. Clark may still have a point in this being a 
net thermal balance. If I remember Andersson's data correctly, 
during his experiments his goats reached a lower level of heat ex- 
change where there was established a steady state heat balance 
which had been approached sharply. It was not reached gradually as 
you might expect. 
DR. FREEMAN: There is a good deal of other evidence, how- 
ever, that this level of 107 F, or about 41 C, is a critical point. 
DuBois wrote on this issue. He pointed ouf that fevers above 
41.11 C are quite rare, and postulated that there is some kind of 
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