BULLETIN- 565, U. S. DEPARTMENT OF AGRICULTURE, 



EGG WITH YOLK SLIGHTLY STUCK TO THE SHELL. 



(Plate XI.) 



OUT OF THE SHELL. 



BEFORE THE CANDLE. 



Air space: Enlarged ; lower wall may 

 be movable in outline. 



White: Thin, may be streaked with 

 yellow if yolk sac is ruptured. 



Yolk: Attached to shell by a small 

 area of the yolk sac ; waves when 

 egg is turned ; as the yolk sac is 

 weak, it frequently may be found 

 to be ruptured, with contents flow- 

 ing into the white, or twisting dur- 

 ing candling may tear the yolk from 

 the shell, when the appearance be- 

 fore the candle will be similar to 

 that of a mixed rot. Occasionally, 

 if the yolk has just begun to stick 

 to the shell, turning the egg in 

 front of the candle may free the 

 yolk without breaking its sac, when 

 it is graded as a good egg. 



Distinguishing characteristic: The 

 sticking of the yolk by a small area 

 so that it sways easily when the egg 

 is turned. 

 Inedible. 

 Occurrence: Very common in summer 



MOLDY 



(Plate IV, figure 



BEFORE THE CANDLE. 



Air space: Enlarged; lower outline 

 may be movable. 



White and yolk: Mold shows as black 

 or grayish areas inside shell. If 

 egg is damaged, the growth follows 

 the line of the crack. The growth 

 may be confined to the shell, in 

 which case the contents of the egg 

 will appear normal ; or it may be in 

 the air cell or the white, in which 

 case its presence is detected by dark- 

 colored patches ; or it may extend 

 to the yolk, which in this stage is 

 heavily attached to the shell and ' 

 covered with dark spots. In an ad- 

 vanced stage of mold growth the 

 whole egg may appear black. 



Distinguishing ch a rac t eristic : 

 Black patches of mold growth. 



White: Thin and clear, or may be 

 streaked with yellow if yolk is 

 broken. 



Yolk: If whole in the shell, it is 

 broken when the egg is opened, leav- 

 ing a yellow mark on the shell at 

 place of contact. If yolk was both 

 stuck and broken in the shell, it will 

 have the appearance of a mixed rot 

 when removed from the shell. If 

 yolk was very lightly stuck it might 

 drop out of the shell without break- 

 ing, in which case the egg would be 

 classed as good. 



Distinguishing characteristic: A 

 broken yolk and a yellow mark on 

 the shell where the yolk is stuck. 



and autumn. 

 EGG. 

 2; Plate XII.) 



OUT OF THE SHELL. 



White and yolk: Normal, if the mold 

 growth has not extended beyond 

 the shell. If the mold is growing 

 in the white it is seen as small 

 patches on the shell, and the yolk 

 may be whole but is usually weak. 

 Sometimes the shell is colored blue 

 or red by the mold growth. If the 

 mold has invaded the yolk so that 

 it sticks to the shell, it then has the 

 appearance of an egg with a heavily 

 stuck yolk. 



If the mold growth has taken 

 place in cold temperatures, the in- 

 fected areas will be gelatinous. 



Distinguishing characteristic: In- 

 fected areas either dark in color or 

 gelatinized. 



Inedible. 



Occurrence: Throughout the year among eggs held in damp surroundings. 



1 Illustrated in color in U. S. Dept. Agr. Bui. 224, PI. XV. 



