Incubation 



1861 



dinarily at the large end of the egg, but occasionally one is found a little 

 at one side or near the small end. Various positions of the air cell, and 

 also the comparative sizes of the air cell at different periods of incubation, 

 are shown in Figs. 73 and 74. 



Fig. 71.— Dead germs after seven days of incubation (2, 3, 4, 5, and 6), to be compared with 

 a live germ as seen in i and in Fig. 70 {4 and 5); i, Live germs in a double-yolked egg; 2, 

 blood ring and germ stnck to shell; 3, blood ri^ig; 4, floating germ; 5, floating germ and 

 blood ring; 6, blood ring 



THE HATCHING PERIOD 



Hatching time is a critical period in incubation, and special attention is 

 necessary to the successful operation of the incubator. In most cases the 

 incubator door should not be opened after the nineteenth day, and all work 

 requiring handling of the eggs or opening of the door should be completed 



