854 



PERIODIC FUNCTIONS IN MAMMALS 



Fig. 26. Daily routine, synchronizer of rhythms in human beings (see 

 text). 



bringing about 2 



days" and 2 "nights" during one 24-hr period by 

 illuminating the cage and feeding her animals from 9 a.m. to 3 p.m. 

 and from 7 p.m. to 1 a.m. Under such conditions, she registered two 

 periods of motor activity and two peaks in body temperature and 



