THE TEMPERATURE OF THE MONKEY AND ITS DIURNAL VARIATION. 103 



exception (see fig. 15, p. 97). This does not agree with what Chossat found in 

 pigeons. In his experiment during the period of inanition the daily variation became 

 much exaggerated. 



From our experiments, then, we may conclude that the temperature of the monkey 

 is much more influenced by the withholding of food for abnormally long periods than is 

 that of man, and in this respect, as in others, e.y. muscular exercise, it is more sensitive 

 to those external conditions which are held to modify the body temperature. 



SUMMARY. 



1. The mean rectal temperature of the monkey may be stated to be 38° C. — about 

 1 ° C. higher than that of man. 



2. The range of the diurnal temperature variation is from 2° to 3° C. — twice or 

 thrice as great as in man. 



3. In the monkey the temperature of the axilla is as a rule from 01° to 0'2° C. 

 higher than that of the rectum. 



4. The temperature is more susceptible to outside influences than in man, e.g. 

 muscular exercise, and inversion of the daily routine leads to an inversion of the 

 diurnal temperature curve. The experiments of Mosso and of Benedict show that this 

 is not the case in man. 



5. Nevertheless, when monkeys are left to themselves in continuous darkness or 

 continuous light, the temperature curve tends to assume the normal type. 



6. Total darkness for a week was found to lower the mean temperature 0*4° C. below 

 the normal, but continuous exposure to the light (natural and artificial) for the same 

 time did not raise it above the normal. 



7. Total abstinence from solid food for three days produced a distinct fall in the 

 temperature, which was most marked during the second day, and at the end of three 

 days after feeding was resumed it had not returned to the normal. 



8. Temperature control in man is much more complete than in the monkey or any 

 of the lower animals. 



(The expenses of this research were borne in part by a grant from the Carnegie 

 Research Fund.) 



REFERENCES. 



(1) Davy, Researches, pt. i. p. 181. 



(2) Pembrey, Jour, of Physiol., vol. xxvii. (1901), p. 80. 



(3) Quincke, Arch. f. exper. Pathol, u. Pharmakol., xv. S. 1. 



(4) Ringer and Stuart, Proc. Roy. Soc. Loncl., 1877, vol. xxvi. p. 187. 



(5) Carter, Jour. Nerv. and Ment. Dis., 1890, vol. xv. (new series), p. 782. 



(6) Benedict, Amer. Jour, of Physiol., 1904, vol. xi. p. 143. 



(7) Mosso, Archives italiennes de bio/., 1887, vol. viii. p. 177. 



