THE INCUBATION OF HENS' EGGS 



227 



latter will usually he readily recognized by the ahsence of 

 i)loodvessels and a irciieral indefiniteness of outlinr. 



Fio. lor, 



A convenient arrangement for sunlight testing. 1, tray for nntcsted 

 eggs; 2, tray for fertile eggs; 3 and 4, trays for unfertiles and dead germs; 

 5, prepared roofing with egg opening placed over window. (Courtesy of 

 Cornell Reading Courses.) 



Fi(i. 106 



Testing eggs in the sunli<:ht. 



