Incubation. — Part II 



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chances of its hatching. Should the egg contents immediately below the 

 air cell appear uneven and indistinct and the remainder of this division 



H S 



Fig. 35. — Eggs as they appear when held before tester after seven days of incubation, 

 compared with fresh egg: I, Fresh egg; 2, infertile egg; 3, weak germ; 4, strong germ 

 as most commonly fou7id; 5, strong germ very near air cell; 6, germ not visible 



show no development of the embryo as in the other eggs, it may be con- 

 cluded that the germ is dead. 



In Fig. 37 are shown drawings of some eggs containing living germs on 

 the fourteenth day of incubation, and of other eggs in which the embryo is 

 dead. By comparing the air cells as shown in Figs. 35 and 36 with those 

 shown in Fig. 37, it will be seen that the air cell increases in size during 

 the first two weeks. This increase continues until about the nineteenth 



