14 
BULLETIN 391, U. S. DEPARTMENT OF AGRICULTURE. 
Table VI. — Relation of bacteria in eggs to position of yolk — Continued. 
III. EGGS CONTAINING ORGANISMS FERMENTING LACTOSE BILE. 
Position of yolk. 
Number 
examined. 
Number 
positive. 
Per cent 
positive. 
Free moving 
1,735 
236 
9 
48 
7 
1 
2 76 
Settled 
2 97 
11 11 
Total 
1,980 
56 
2 7 
DESCRIPTIONS AND BACTERIAL COUNTS OF EGGS GRADED OUT OF 
THE SHELL. 
The fitness for food purposes of eggs sold in the shell is determined 
in the industry principally by candling. In addition to this exami- 
nation, the progressive concerns which are preparing frozen and desic- 
cated eggs grade each egg very carefully out of the shell according 
to its odor and appearance. Practically all of the cooperating houses 
used clear, uncolored glass cups in examining the eggs to facilitate 
grading, as the physical condition of an egg is seen more easily in 
a transparent than in an opaque container. Many eggs with light 
green whites are not detected in a metal cup because the container 
masks the color. 
The system of grading worked out in the cooperating plants was 
used for the grading of the eggs when removed from the shell. An 
egg in which the yolk was whole, the albumen clear, and the odor 
normal was graded as good. If the yolk appeared whole before the 
candle but broke when dropped into the cup and the odor was good, 
the egg was graded as fit for food purposes. Any egg in which the 
yolk had so deteriorated that it was materially mixed with the white 
was discarded, even though there was no odor, as were also all addled 
eggs, the advanced stage of this type of egg. Eggs with heavily 
mottled yolks were graded as bad. (See Plate II.) All eggs in which 
the yolk clung to the shell, even to a slight degree, all eggs with green 
whites, and eggs containing diffuse blood or embryos showing blood 
rings were rejected. Eggs with an unpleasant odor, for example, 
musty eggs, sour eggs, and very strong eggs — eggs in which the 
natural odor of the egg is increased — were classed as bad. The 
descriptions and bacterial findings in the case of a typical lot of 
individual eggs are given in Table VII. 
Of the eggs in the experimental samples which had been passed by 
the candlers as edible, 171, or 8.3 per cent, were classed as bad when 
graded out of the shell by appearance or odor. Had these inedible 
eggs been sold in the shell their condition would not have been seen 
until they were broken by the consumer. They would be eliminated 
by the trained breaker from frozen products. 
