THE TEMPERATURE OF THE MONKEY AND ITS DIURNAL VARIATION. 



89 



39-3 at 11 p.m. on 23rd), in D 3*4° (357 at 3 p.m. to 39'1 at 1 a.m. on 23rd), in E 

 2-1° (367 at 3 p.m. to 38'8 at 3 a.m. on 22nd), in F 17° (36'6 at 3 p.m. on 22nd to 

 38'3 at 11 a.m. on 21st), and for mean of all 2'2° (36'6 at 3 p.m. on 23rd to 38'8 at 

 3 a.m. on 24th). 



The summary given in the following table shows how the mean temperature, range, 

 and times of minima and maxima were affected by the conditions obtaining in 

 Periods I., II. , and III. 



PERIOD I. — Normal. Resting from 9 p.m. to 9 a.m., Active from 9 a.m. to 9 p.m. 



Monkey. 



Mean 

 Temperature. 



Mean 

 Range. 



Minimum. 



Maximum. 



B . 

 C . 

 D . 



E . 

 F . 



Average 



38-34 

 38 37 

 37-67 



38-07 

 38-04 

 3808 



1-58 

 1-73 

 1-84 

 1-47 

 1-11 

 1-62 



37'42 at 5 a.m. 

 37-47,, 3 ,, 

 36 72,, 5 ,, 

 37-25 ,, 5 „ 

 37-42,, 3 ,, 

 37-25 ,, 5 ,, 



39-0 at 1 p.m. 

 39-2 ,, 5 ,, 

 38-56 ,, 7 ,, 

 38-72 „ 7 „ 

 38-53 ,, 5 ,, 

 38-87, 5 ,, 



PERIOD II. — Inverted. Resting from 9 a.m. to 9 p.m., Active from 9 p.m. to 9 a.m. 



B . 



38-08 



1-35 



37 '25 at 7 p.m. 



38 "6 at 3 and 7 a.m. 



C . . 



38-08 



1-51 



37-30,, 3 ,, 



38-81 ,, 7 a.m. 



D . 



37-43 



1-66 



36-54 ,, 3 „ 



38-20 ,, 7 ,, 



E 



37-97 



1-37 



37-24,, 1 ,, 



38-61 ,, 1 and 3 a.m. 



F 



37-75 



1-05 



37-09,, 7 ,, 



38-14 ,, 3 a.m. 



Average 



37-84 



1-27 



37-19 ,, 3 ,, 



38-46 ,, 7 ,, 



PERIOD III. — Resting from 3 a.m. to 3 p.m., Active from 3 p.m. to 3 a.m. 



B . 



38-12 



1-93 



36-83 at 1p.m. 



38-76 at 3 a.m. 



C . 



38 -02 



1-95 



37 05,, 11 a.m. 



39-00 ,, 3 ,, 



D . 



37-48 



2-18 



36-47 ,, 1 p.m. 



38-65 ,, 1 ,, 



E 



37-85 



1-44 



37-12 „ 11 a.m. 



38-56 ,, 3 ,, 



F . 



37-75 



0-89 



37 "31 at 1 and 3 p.m. 



38-20 ,, 1 ,, 



Average 



37-82 



1-63 



36-97 ,, 1 p.m. 



1 



38-60 ,,3 „ 



The mean temperature is highest during the normal period and lowest during the 

 third period ; the diurnal variation is greatest during Period III. and least during 

 Period II. Several days elapsed before the swing was well established ; this will be 

 evident from an examination of chart I., and when the mean temperatures of the first 

 and last days of the reversed routine (Periods II. and III.) are contrasted (see fig. 7). 



Effect of Darkness and Light. 



To determine what part was played in the production of the diurnal wave by the 

 alternation of light and darkness, two further experiments were undertaken. During 

 the first of these — Period IV. — which extended from 3 a.m. on April 26th till 9 a.m. 

 on May 2nd, the monkeys were kept continuously in the dark, except for the few 



TRANS. ROY. SOC. EDIN., VOL. XLV. PART I. (NO. 4). 12 



