222 POULTRY PRODUCTION 



restricted for the purpose of conserving the moisture left 

 in the machine after the removal of the sand trays. As 

 soon as the hatch is over the ventilators should be opened 

 fully. 



Testing. — It is customary to test the eggs at the end of the 

 first week in order that all eggs that are not developing may 

 be removed. This is desirable in order to avoid breaking 

 eggs having dead germs in turning, and that the developing 

 eggs may have the added room. In the case of poor fertility 

 the eggs from two or more machines may be combined in 

 one machine. White-shelled eggs may be tested as early as 

 the third day, while with very dark-shelled ones the germ 

 often cannot be seen until the eighth or ninth day. 



The two classes of eggs tested out are "infertiles" and 

 "dead germs." Technically the term "infertile" refers to 

 the fact that an egg has never been fertilized, while practically 

 it includes those which have started to develop but have died 

 before progressing far enough to be distinguished before the 

 tester. The dead germ refers to one that is fertile in which 

 the germ has died after developing far enough to be seen 

 before the tester. 



The so-called infertile egg appears to be clear save for a 

 floating shadow, which is easily distinguished as the yolk. 



The live germ is spider-like in appearance, the body of the 

 embryo representing the body of the spider and the radiating 

 bloodvessels its legs. The live germ floats about freely in the 

 contents of the egg when the egg is rotated before the tester. 



The dead germ may be recognized by the absence of the 

 bloodvessels, its adhering to the shell, or by the quite typical 

 pink ring surrounding it which is called the blood ring. 



The second test is commonly made at the end of the second 

 week. If the first has been accurately done there will be 

 only dead germs to test out. The live embryo at this time 

 appears to nearly fill the egg. In the one or two light spaces 

 which are usually present, bloodvessels will be noticed and the 

 embryo chick will frequently be seen to move when the egg 

 is rotated. 



The dead germs may vary in appearance from typical 

 blood rings to embryo chicks of nearly normal size. The 



