THE BODY TEMPERATURE OF THE DOMESTIC FOWL (GALLUS GALLUS). 615 



Table V. (From Eycleshymer.) 



Surface Temperature of Hen compared with Temperature of Centre of Egg on 

 Successive Days of Incubation. In Series I. the temperature was taken without 

 disturbing the hen; in Series II. the hen ivas raised from the nest and a 

 clinical thermometer placed in the groin. 



I. 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



Hen . 



Egg . 



°C. 



39-0 

 36-7 



°C. 



39-4 



37-9 



•c. 



39-7 

 38-1 



°C. 



40-0 



38-1 



°G. 



39-9 



38-0 



°C. 



40-5 

 38-3 



°C. 

 40-3 



38-8 



°C. 



40-3 

 39-2 



°C. 

 40-5 

 38-7 



°C. 



40-5 

 38-9 



I. 



11 



12 



13 



14 



15 



16 



17 



18 



19 



20 



Hen . 

 Egg • 



40-4 



38-8 



40-6 

 39-0 



40-3 

 38-9 



40-5 

 39-2 



40-6 

 39-0 



40-5 

 39-4 



40-3 

 39-1 



40-4 

 39-4 



40-3 

 39-4 



40-3 

 39-4 



II. 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



Hen . 



Egg • 



39-4 

 375 



40-5 



37-8 



40-4 

 37-9 



40-1 

 38-1 



40-6 

 38-1 



40-5 

 38-3 



40-4 

 38-1 



40-4 

 38-1 



40-5 

 38-6 



40-5 

 38-6 



II. 



11 



12 



13 



14 



15 



16 



17 



18 



19 



20 



Hen . 



Egg • 



40-4 

 38-6 



40-5 

 38-4 



40-4 

 38-2 



40-4 

 38-8 



40-6 

 38-9 



40-5 



38-8 



40-8 

 39-0 



40-0 

 38-9 



40-0 

 39-1 



40-0 

 39-1 



during the hatching. After the hatching is completed, and especially on the second and 

 third days when the hen begins to move about and make provision for the wants of her 

 brood, the body temperature rises distinctly and is higher than that of the control hen, 

 a fact which is to be accounted for by the greater activity of the mother-hen. 



However, while the temperature of the incubating hen is lower during the day than 

 that of the control, during the night and early morning it is frequently higher, so that 

 if the temperature means for the twenty-four hours are compared in the two cases, that 

 of the brooding hen is only slightly the lower. (See Table VI.) The difference, 

 therefore, is not to be found so much in the mean temperature as in the diurnal tempera- 

 ture range. This is greatly reduced in the brooding hen, so that the internal body 

 temperature remains much more uniform throughout the whole period of incubation 

 than in its ordinary active state. (See figs. 1, 3, and 5.) After hatching, the daily 

 variation in the mother-hen is greater than in the control. (Figs. 2, 4, and 6.) 



This uniformity in the temperature of the brooding hen is probably due entirely 

 to the absence of the regular alternation of rest and activity, the lower temperature 



