472 



POULTRY PRODUCTION 



them unfit for successful preservation by storage or preser- 

 vative compounds are as follows: 



1. Weak or Heated Eggs. — With fertile eggs the develop- 

 ment of the embryo to a period corresponding to eighteen 



Fig. 228 



Fertile egg allowed to die after thirty-six hours of incubation, showing a 

 slight blood ring. (Courtesy of Bureau of Animal Industry.) 



to twenty hours of normal incubation temperatures brings 

 about the condition known as heated. The infertile egg will 

 not show heat so quickly, but in either case the color of the 

 yolk is intensified, the yolk moves about with greater freedom 

 when the egg is rotated, showing that the albumen has become 



