8 
BULLETIN 391, U. S. DEPARTMENT OF AGRICULTURE. 
The number of bacteria in the eggs which contained organisms 
varied widely for the three groups, as can be seen' from Part II of 
Table III. This is what would be expected, because after bacteria 
have once entered an egg the number present depends upon condi- 
tions favoring growth, such as warm temperatures. 
These data substantiate the popular belief that organisms may 
penetrate eggs with sound shells if unfavorable conditions, such as 
filth, moisture, and high temperatures, are incurred during marketing, 
but not to such an extent as they penetrate cracked shells. The 
chance of contamination is greater in the case of leaking eggs, owing 
to exposure of the contents. 
] JO.S% 
Fig. 2. — Relation of bacteria to soundness of shell. Total bar = per cent containing 
bacteria. Black portion of bar = per cent containing organisms fermenting lactose 
bile. 
Table III. — Relation of bacteria in eggs to soundness of shell. 
I. EGGS CONTAINING BACTERIA. 
Description of shell. 
Number 
examined. 
Number 
positive. 
Per cent 
positive. 
Whole 
1 1, 167 
784 
101 
101 
146 
31 
8.7 
18.6 
30.7 
Total 
2,052 
27S 
13.5 
i 29 blind checks, 2 of which (6.9 per cent) contained bacteria, are included in this number. 
II. VARIATION IN BACTERIAL CONTENT OF EGGS CONTAINING BACTERIA. 
Number of bacteria per ec. 
Description of shell. 
101.0 1,000. \.»%t° 
10,001 to 
50,000. 
50,001 to 
100,000. 
100,001 to 
500,000. 
Over 
500,000. 
Total 
num- 
herof 
Num- 
ber 
eggs. 
Per 
cent. 
Num- 
ber 
eggs. 
Per 
cent. 
Num- 
ber 
eggs. 
Per 
cent. 
Num- 
ber 
eggs. 
Per 
cent. 
Num- 
ber 
eggs. 
Per 
cent. 
Num- 
ber 
eggs. 
Per 
cent. 
eggs. 
Whole 
- 33 
35 
8 
32.7 
24.0 
25.8 
15 
24 
6 
14. S 
16.3 
19.4 
8 
25 
3 
7.9 
17.1 
9.7 
9 
10 
1 
8.9 
6.8 
3.2 
20 
5 
6.9 
13.7 
16.1 
29 
32 
8 
28.7 
21.9 
25.8 
101 
Cracked 
146 
Leaking 
31 
Total 
76 
27.4 
45 
16.2 
36 
12.9 
20 
7.2 
32 
11.5 
69 
24. S 
278 
III. EGGS CONTAINING ORGANISMS FERMENTING LACTOSE BILE. 
Description of shell. 
Number 
examined. 
Number 
positive. 
Per cent 
positive. 
Whole ' 
1,132 
751 
97 
6 
32 
8 
1.4 
Cracked 
4.3 
Leaking 
8.2 
Total 
1,980 
56 
2.8 
