THE INCUBATION OF HENS' EGGS 



207 



difference is doubtless due to the increasing animal heat 

 generated by the growing embryo. 



It should be recognized that this is l)ut a single test, 

 which should be supplemented by many further tests before 

 drawing too definite a conclusion. It leads the way, however, 

 to an understanding of the principle of governing the tem- 

 perature of the incubator. That principle is to carry such 

 a temperature in the egg chamber that the egg will be as 

 nearly as possible the same temperature as when under a hen. 



Table XXIX. 



Hon 



Egg 



102.2;103.0 103.5 104.0 103. S 10.5.0 104,6 104.5 105.0 105.0 

 98.0100. 2 100.5 100.5 100.4 101.0 101.8 102,5 101. C 102,0 



16 



IS 



Hen 



Egg 



104.8 105.2 104.5 105.0 105.2 105.0 104 104.8 104,5 104.5 

 101.8 102.2 102.0 102,5 102,0 103.0 102 4 103,0 103,0 103.0 



In carrying the egg chamber temperature at 102° to 103° 

 the first half and 103° to 104.5° the remainder of the period, 

 Eycleshymer' observed the temperatures shown in Table 

 XXX. " 



Table XXX. 



Inc'b 



Egg 



102.0 



102.0 103,0 102,0102.5 103,0 102,5 102,0 103.0 103.5 



99.5 100.0 101,0 100,5 100.5 101,0 100,0 100,0 101.0 101 5 



Iiio'b ,103.0 103.5 104.0 103.5 104.0 104.5 104.0 103.5 104.0 104 5 



l']gg 101.5 101.8il02,0 102.5 103.0 10,3.0 103,0 102,.''- 102 5 103,5 



Biological Bulletin, May, 1907. 



