328 FRANCIS B. SUMNER 



figures for these same individuals which it is allowable to use 

 for comparison, but the table indicates a mean fall of 1.56° before 

 the following morning. Other observat'ons render it unlikely 

 that this difference is due to a difference in the time of day. If 

 we consider the six^^ available afternoon readings for the other 

 adult male mice of the warm-room group (table 7, January 14 

 and 19), we find a mean temperature of 35.83° (maximum), or 

 2.47° lower than the earliest figures in table 9. It seems likely 

 therefore, that these abnormally high temperatures were due to 

 cause suggested, but the experiment should have been repeated 

 with these and other mice. 



Various writers have found evidence of a regular diurnal tem- 

 perature rhythm in man,^^ though this probably depends upon 

 the usual daily routine of work and rest. Unfortunately, few 

 data are available in my tables which permit of a comparison 

 of 'forenoon' and 'afternoon' figures under otherwise identical 

 conditions, but such as there are furnish no evidence of a generally 

 higher afternoon temperature. Indeed, there would be little 

 point in comparing the 'a.m.' and 'p.m.' figures of my tables, even 

 if this were permissible, since the observations were made, for 

 most part, late in the morning and early in the afternoon, in. 

 some cases extending through the noon hour. In only two sets 

 of tests (tables 9 and 11) were any of the determinations made 

 in the evening. On both of these occasions, abnormally high 

 temperatures were met with. In table 9, no other explanation 

 can be suggested than a tendency for the temperature to rise in 

 the evening, since it had fallen after the third and fourth tests 

 for the day. In table 1 1 , however, this tendency (?) is complicated 

 by another factor, namely, the previous transfer of these mice 

 to a much warmer atmosphere. In any case, these evening figures 

 will not be used in the general comparisons of warm-room and 

 cold-room mice. 



It has been stated by some writers that the sexes differ some- 

 what in their mean body temperatures. In tables 7 and 10 we 



1^ Two of these readings are characterized as unreliable, but they probably err 

 in being too high rather than too low. Furthermore, the room temperatures are 

 considerably higher in the case of the table 7 mice. 



1' See Pembrcy, in Schafer's Physiology, pp. 798-803. 



