AND OF EXPOSED MUCOUS MEMBRANES. 655 
Steffeck (1892) has examined the vaginal secretion of twenty-nine 
pregnant females who had not been subjected to digital examina- 
tion, and found Staphylococcus pyogenes albus in nine, Staphylo- 
coccus pyogenes aureus in three, and Streptococcus pyogenes in one. 
These results indicate that puerperal septicemia from self-infection 
may occur in exceptional cases. In seventeen of the twenty-nine 
cases examined none of these pyogenic micrococci were found. 
Hofmeister (1894) has shown that bacteria are found not only 
upon the mucous membrane of the meatus urinarius in man, but 
that they may usually be obtained from the urethral canal at a depth 
of eight centimetres or more, although the number rapidly diminishes 
in the deeper portion of the urethra. 
Walthard (1895) arrives at the conclusion that while in pregnant 
females bacteria are constantly found in the vagina and the lower . 
portion of the cervical canal, they are absent from the upper part of 
the cervical canal, the uterus, and the tubes; and that during the 
puerperal condition the uterine cavity is preserved from spontaneous 
infection per vias naturalis by the plug of mucus in the cervical 
canal. In the vaginal secretions of one hundred pregnant women, 
. who had not been subjected to a digital examination, streptococci 
were obtained twenty-seven times in cultures. These were not viru- 
lent, but, according to Walthard, these saprophytic streptococci be- 
come virulent when, owing to a diminished resisting power, they are 
enabled to invade the tissues as parasites. 
Krénig (1894) concludes from his investigations that the vaginal 
secretions of pregnant women are usually so acid that Streptococcus 
pyogenes could not multiply in them; also that when the secretion is 
normal it is almost always sterile. 
Déderlein (1894) insists that the failure of Krénig to obtain micro- 
organisms in his cultures was due to the fact that suitable media 
were not used; also that certain bacilli are constantly found in nor- 
mal, acid vaginal secretions, and that in the pathological secretions 
which are feebly acid, neutral, or in some cases slightly alkaline a 
great variety of bacteria are found, including Streptococcus pyo- 
genes, as demonstrated by himself and other investigators. In a 
later paper (1894) Kroénig reports his success in obtaining cultures 
from normal, acid vaginal secretions by using acid media and by 
cultivating under anaérobic conditions. He reports also that patho- 
genic bacteria (streptococci, staphylococci, and Bacillus pyocyaneus) 
introduced into the vagine of pregnant women lose their power of 
reproduction in from six to forty-eight hours (streptococci did not 
grow after six hours). Ina still later communication (1894) Kronig 
reports that the bacteria present in the vaginal secretions of pregnant 
