18 
BULLETIN 565, U. S. DEPARTMENT OF AGRICULTURE. 
EGG WITH YOLK SLIGHTLY STUCK TO THE SHELL. 
(Plate XI.) 
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. 
D is t ing uishing char act erist i c : 
Black patches of mold growth. 
OUT OF THE SHELL. 
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. 
D isiingu ish ing eli aracteristic : 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. 
