356 FRANCIS B. SUMNER 



on the last two days of the experiments seem to have resulted in 

 a marked increase in body temperatm-e, though the small number 

 of figures and certain other circumstances render this interpreta- 

 tion somewhat doubtful. It must be noted, moreover, that the 

 mean increase which followed the change from 13° to 31° was only 

 about 0.4° for the two sexes. On the next day, the limits gf 

 normal adjustment were perhaps overstepped. Indeed, several 

 rats which were kept in the same room died, apparently as a 

 result of the heat. 



Berkeley, California 

 September 16, 1913 



