THE EGG. 



17 



Fig. 3. 



On the fifth or sixth da}- of iucu- 



bation, a strong, fertile egg will look 



like Figure 3. The air-sack is slightly 



enlarged and from a dark center fine 



red lines are seen to radiate. There 



is also a slight cloudiness about this 



dark spot or germ, and the germ can 



be seen to move slightly as the egg 



is revolved. 



It often happens that the germ begins to develop 



and dies before the sixth da}'. In this case the red 

 lines are indistinct, or absent, and in 

 their place is a dark circle enclosing 

 the germ as appears in Figure 4. When 

 the egg is revolved this dead embryo 

 floats aimlessly about in the surround- 

 ing contents. 



All infertile eggs that were fresh 

 when incubation began, will remain 

 clear up to the sixth day, or even lon- 

 ger, but a stale egg shows a cloudy spot in the center 



and a large air sack. When opened, the yolk sack is 



apt to break and the contents to run together, or, as 



we say, become "addled." 



All such eggs, as well as those that contain dead 



embryos, and all clear or infertile 



eggs should be removed at this first 



testing. 



A second testing of eggs should 



be made on the tenth da}-. By this 



time the air sack has still further en- 

 larged and the growth of the embrj'O 



Fig. ^. 



Fig. 4. 



