STUART, D. G. 
DR. STUART: Yes, but the differences between physiological 
tremor (microvibration) and shivering are more obscure. My 
personal feeling (subject to experimental confirmation) is that 
shivering is a cold- induced exaggeration of the amplitude of the 
neurological component of physiological tremor. Dr. Earl Eldred 
and 1 are particularly interested in patterns of alpha and gamma 
motorneuron and muscle receptor discharges during diverse 
tremors. The literature on some aspects of this will be reviewed 
shortly (Stuart, D. G., E. Eldred, and Y. Kawamura. Neural regu- 
lation of the rhythm of shivering. In "Temperature - Its Regulation 
and Control in Science and Industry. " C. M. Herzf eld (ed.) Washing- 
ton, Reinhold Publishing Corp. In press 1961). I feel your question 
is most pertinent but cannot be answered satisfactorily until more 
experimental evidence has accumulated. 
DR. CLARK: I would like to mention the figure that I showed of 
one of Keller's dogs. It has a lesion that fits in beautifully with what 
you have been saying because it went much further dorsal medially 
than it did laterally, so it would spare those Crosshatch areas you 
have outlined in your drawing but would have hit the medial ones. 
DR. STUART: With respect to the role of the hypothalamus in 
shivering, 1 believe that the data from our laboratory are in agree- 
ment with Keller's data. 
DR. CLARK: And that dog, of course, could pant but could not 
shiver. 
DR. MINARD: I would like first of all to express my great 
appreciation to the laboratory and to the speakers for a very illum- 
inating two and a half days. There are two statements I would like 
to make just to throw them out for possible criticism or disagree- 
ment; and the reason I am doing this is because there will be some 
studies reported from the Naval Medical Research Institute on 
humans in which these two statements are fairly basic in the inter- 
pretation of the results. The first of these statements is that the 
posterior hypothalamus is blind to temperature; that is, that it has 
not been possible to elicit responses by changing the temperature 
of the posterior hypothalamus. The second of the two statements is 
that in a shivering animal, heatingof the anterior hypothalamus will 
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