HATCHING THE CHICKS 69 



When the eighteenth day closes, cooling and 

 turning of the eggs should cease, for the chicks are 

 almost ready to hatch. In very dry climates, the 

 eggs may then be sprinkled with water at a tempera- 

 ture of 103. Much might be written about the 

 moisture question, but experts differ and the safest 

 plan is to follow implicitly the directions which 

 come with the machine. 



On the seventh day the eggs may be tested, and 

 it is well to perform this operation again on the 

 fifteenth day. The test is made by placing the eggs 

 between the eye and a strong light and excluding 

 all other light. In practice, a tester which fits over 

 a lamp chimney and allows light to come only 

 through an opening at one side is the easiest to 

 handle, as both hands are left free. When an egg 

 is placed tightly against the frame around the open- 

 ing, the contents will be illuminated. If the egg is 

 infertile, it will be entirely clear ; if there is a chick 

 in it, an opaque spot will indicate its presence. On 

 the seventh day this spot will be small and lines will 

 radiate in all directions. These lines are blood ves- 

 sels running out from the heart. On the fifteenth 

 day the chick will be large enough to almost fill the 

 shell, appearing as a dark mass. An egg containing 



