MIYA, MARCUS AND PHELPS 



the bcxiy temperature is very easily changed, and this isn't a 

 matter of how far you insert the probe into the rectum. We use 

 one centimeter. We would go further, but we get a higher in- 

 cidence of perforated colon and so on. This difference among 

 mouse strains is fairly important, it seems to me, because I 

 am prepared to propose that in virus infections, the change in 

 body temperature is quite important, and I am really more im- 

 pressed with the effect of the temperature of the tissues than 

 with factors like stress. The effect of cold on viral infections 

 has been quite variable, quite contradictory, and I wonder if 

 the differences among not only species, but among strains of 

 mice may not be partly responsible for this variability. As Dr. 

 Campbell indicated, and as my experience has been, too, you 

 can hardly change the body temperature of a rabbit, regard- 

 less of what you do. If you do go down low enough in environ- 

 mental temperature, the temperature suddenly begins to change 

 and it goes right on down and the animal quickly dies ; but up 

 to that point, you cannot really lower it. But in our experience, 

 the mouse temperature is quite readily changed. If you raise 

 the environmental temperature, you raise his body temperature. 



MIYA: If you plot distance into the rectum on the abscissa 

 and the temperature on the ordinate, you notice almost a linear 

 relationship. 



MARCUS: From two centimeters down to one? 



MIYA: Well, we took it at .5, 1.0, 1.5, and 2.0 cm down, 



PREVITE: I think this has also been confirmed by Halberg 

 and Spink.^ In my own experiences, the distance the probe was 

 inserted made a significant difference in the rectal temperature 

 recorded. 



MARCUS: We have had no difficulty with rupturing. We haven't 

 penetrated too many. 



1 Halberg, F., and W. W. Spink. 1956. Laboratory Investigation. 



206 



