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.) 
OUT OF THE SHELL. 
White and yolk: Fresh, stale, or de- 
teriorated. 
Distinguishing characteristic: 
None. 
BEFORE THE CANDLE. 
Air space: Always on top no matter in 
what position the egg is held. 
White and yolk: Fresh, stale, or de- 
teriorated. 
Distingu ish ing 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 <»r black in 
color. 
Distinguishing c h a r<i <■ t e r i s / ic: 
Black color. 
OUT OF THE SHELL. 
The color of the mixture varies 
from gray-green to dirty yellow. It 
may contain a decomposed embryo. 
D is t ingu ishing ch a racteristic: Dis- 
colored mixture with bad odor. 
Inedible. 
Occurrena : Mosl frequently during spring and late summer months. 
^Illustrated in color in l". S. Dept. Agr. Bui. 224. PI. XIV. 
