DOMESTIC MAMMAL ADAPTATIONS 



WEST: It seems as though it were the same as maximal activity. 



KLEIBER: The only reason I am not particularly happy with the 

 straight line is that usually these things do not stop all at once. 



WEST; I was thinking of the work that Dr. Jansky showed, where 

 all the maximal rates were nearly parallel; this would be a similar 

 situation. 



KLEIBER: It may be that within a certain range it might be 

 parallel with the other curve for resting metabolism, and then 

 smooth out. 



JO HANSEN; I found it very peculiar that you could apply 

 "Arrhenius" so beautifully on the breathing rate of your cows. This 

 is very much different from what I found in the armadillo. They 

 increase their breathing rate suddenly; some marsupials do, too. 



PROSSER: I would also question that Arrhenius plot, because 

 you are plotting the breathing rate against external temperature. 

 What does this mean-?One would think if you are going to extrapolate 

 to a chemically determined rhythm, you should do this against body 

 temperature instead of environmental temperature. 



KLEIBER: Well, the body temperature remains essentially con- 

 stant; that is, within a small range. 



PROSSER: In that case I am wondering what is the meaning of 

 the Arrhenius coefficient. 



KLEIBER: Here you embarrass me, because the meaning is 

 completely unknown to me. It just happens to be so and the only 

 thing which I can deduce is that the breathing rate of the cow is not 

 the same function of environmental temperature as that of the 

 armadillo. 



HANNON; This brings up a question that we have wondered 

 about for a long time. That is, why do small animals lose weight 

 when you first put them in the cold? Is it due to a lack of appetite, 



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