THE; KGG. 17 



On the fifth or sixth day of incu- 

 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 



- -. FIG. 3. 



is revolved. 



It often happens that the germ begins to develop 

 and dies before the sixth day. 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 day. By this 

 time the air sack has still further en- 

 larged and the growth of the embryo 



FIG. s. 



