14 



BULLETIN 565, U. S. DEPARTMENT OF AGRICULTURE. 



WEAK EGG. 



BEFORE THE CANDLE. 



Air space: Enlarged; lower wall usu- 

 ally movable in outline. 



White: Very thin and clear. 



Yolk: Whole, but very weak; may 

 bear a hatch spot and may be 

 mottled. 



Distinguishing characteristic: A 

 weak condition of white and yolk. 



Edible. 



Occurrence: Chiefly during summer. 



OUT OF THE SHELL. 



White: Clear and very thin. 



Yolk: Membrane often breaks when 

 the egg is opened ; may have a hatch 

 spot and may be mottled. 



Distinguishing characteristic: Yolk 

 sac often breaks when egg is opened. 



EGG WITH MOVABLE AIR CELL. 



(Plate IV, figure 1.) 



BEFORE THE CANDLE. OUT OF THE SHELL. 



Air space: Always on top no matter in White and yolk: Fresh, stale, or de- 



what position the egg is held. teriorated. 



White and yolk: Fresh, stale, or de- Distinguishing characteristic: 



teriorated. None. 



Distinguishing characteristics: 



Movable air cell ; much less contrast 



between white and yolk in a weak 



egg than in a fresh egg; gives a 



hollow sound when tapped against 



the shell of an egg with normal 



air cell. 



Edible if contents have not deteriorated. 



Occurrence: During autumn, when the proportion of stale eggs is the greatest, 

 and in those sections where eggs are subject to rough handling. 



MOLDY CRACKED EGG. 



(Plate IV, figure 2.) 

 For description see page 18. 



BLACK ROT. 



(Plate IV, figure 3.) 



BEFORE THE CANDLE. 



Air space: Very much enlarged ; lower 



wall may be movable in outline or 



may be broken. 

 Contents of shell: Gray or black in 



color. 



Distinguishing characteristic: 



Black color. 



OUT OF THE SHELL. 



The color of the mixture varies 

 from gray-green to dirty yellow. It 

 may contain a decomposed embryo. 



Distinguishing characteristic: Dis- 

 colored mixture with bad odor. 



Inedible. 



Occurrence: Most frequently during spring and late summer months. 



illlustrated in color in U. S. Dept. Agr. Bui. 224, PI. XIV. 



