BODY TEMPERATURE OF MICE 329 



find data for a comparison of male and female mice, under closely 

 similar conditions. For statistical purposes, I have divided these 

 into groups such that individuals of one sex may be compared 

 with individuals of the other sex whose temperatures were taken 

 at the same time and in the same room.^" 



We have thus in the warm room three groups of figures (those 

 of January 14, 16 and 19), within which comparisons are possible 

 between the sexes. For each of these groups, the mean of the 

 male temperatures has been found, and the difference obtained 

 between this and the mean of the female temperatures. These 

 differences, for the three groups, are 1.95°, 1.60° and 1.38°, respec- 

 tively. In each case the figure for the females is the higher. 



Among the cold-room lot, we have four groups, for which the 

 differences between the male and female averages are 0.95°, 0.95°, 

 0.02° and 0.80°, respectively. For each of these except the first, 

 the female figure is the larger. 



If we compute the averages of these various group differences,-^ 

 we find that the mean temperature of the females is higher by 

 0.76° than that of the males. 



It is further stated that the temperature of boys and girls is 

 higher than that of adult men and women;-- and for mice 

 Congdon gives the mean temperature of males "approaching 

 puberty"23 as 1.7° higher (at 16°C.) than that of old mice. My 

 own experiments are in general harmony with those of Congdon 

 on this point, though my "nearly adult" males were evidently 

 somewhat older than his. Comparisons of old and young indi- 

 viduals are possible in tables 8, 11 and 12, where we have about 

 38 available figures-^ derived from 24 mice, or 12 of each age. 

 The mean difference, computed as for males and females, is 

 0.66° in favor of the younger mice. 



2° Only the first figures for the day are included in these computations. The 

 'maximum' readings are here employed, those being rejected which are regarded as 

 unreliable (starred). Altogether, we have 17 figures representing 8 males, and 19 

 figures, representing 8 females. 



-1 1 have 'weighted' the various figures according to the method described below. 



2- Pembrey, in Schiifer's Physiology, p. 805. 



-' Dr. Congdon informs me that these mice were two to three months old. 



-* 'Thirty-second' figures only being used. 



