BACTERIA IN EGGS 459 
Permeability of the Shell. The shell about the ege may be regarded 
as a semi-permeability membrane and, therefore, not resistant to bac~ 
teria. Wittich (1851) reported the infection of eggs by molds. Wilm 
(1895) succeeded in infecting eggs with cholera vibrios. When the eggs 
were covered with a broth culture, the organisms passed through the 
shell in from fifteen to sixteen hours, Golokow (1896), Piorowski (1895), 
Lange (1907), and Poppe (1910) demonstrated the same thing with 
other bacteria both pathogenic and non-pathogenic. Opposed to this 
work is that of Mauer (1911), Hoppert (1912), Sachs-Miike (1907), 
Zorkendorfer (1894) and Schlegel (1904). Kossowicz (1913) showed that 
B. proteus penetrated the shell very easily. The above indicates the 
ability of bacteria to penetrate the shells of eggs and this emphasizes 
the necessity of storing eggs under sanitary conditions. 
Bacteria in Egg White. Available data on this subject are con- 
flicting. Many of those who have found no bacteria in egg white have 
assumed that this comp >nent of the egg possesses a bactericidal action. 
Wurtz (1890), Rettger and Sperry (1912), Scholl (1893), Horowitz 
(1902), Turro (1902), Laschtschenko (1909), and Riezicka (1912) pro- 
duce data indicating the same result. Sperry (1913) showed that cold 
storage eggs exhibited the same action. Bainbridge (1911), Poppe 
(1910), Hoppert (1912), Mauer (1911), Laschtschenko (1909) found no 
germicidal action. Mauer was especially interested in B. coli. Rettger 
and Sperry employed B. putrificus and B. edematis maligni as the best 
organisms. Egg white in test tubes was heavily inoculated with the 
test organisms and incubated under conditions favorable for the devel- 
opment of the organisms. In the yolk which was treated in the same 
manner evident putrefaction set in while in the egg white the bacteria 
were destroyed for microscopic examination failed to demonstrate the 
presence of the cells. Hadley and Caldwell (1916) in their excellent 
report on eggs reported data which confirm that of Rettger and Sperry. 
Bacteria in the Egg Yolk. Practically all of the investigators are 
agreed that the yolk contains the greater number of the bacteria. Had- 
ley and Caldwell found 8.7 per cent of 2520 eggs infected in the yolks. 
They quote from other authors: Mauer is said to have found 18.1 
per cent of the yolks to be infected. Bushnell and Mauer raised this 
to 23.7 per cent. Rettger’s data is corrected to show a yolk infec- 
tion of 9.9 per cent covering examinations over a period of three 
years. 
Qualitative studies of the bacteria in eggs have been reported by 
several investigators. Rettger (1913) gives the following bacteria: 
