INFECTION. 131 
intestines, on the other hand, contain great numbers of 
bacteria. Among these the colon bacillus is constantly 
present, and often the streptococcus and other. patho- 
genic bacteria. After typhoid fever the bacilli may 
remain in the intestinal contents for weeks and in the 
bladder and gall-bladder for months. The bacteria 
swallowed to a considerable extent escape destruction 
in the stomach, and thus appear in the intestines. Some 
good observers have stated that bacteria can be absorbed 
through the intestinal wall into the chyle and blood. 
When the intestinal canal is injured, or its circulation 
hindered by strangulation, etc., the bacillus coli and 
some other bacteria may penetrate through the injured 
walls and cause peritonitis or general infection. Under 
certain conditions, as during the debility due to hot | 
weather, the bacteria in the intestines cause, through 
their products, irritation, and in children even serious 
intestinal inflammation. 
The kidneys, bladder, and urethra may be the source 
of infection and may give rise to disease in others. 
Long after an acute gonorrhcea has passed gonococci 
may remain in sufficient numbers to cause a new in- 
flammation or produce infection in others. A cystitis 
may run on chronically for years, and then suddenly 
become acute or spread infection to the kidneys. After 
typhoid fever the urine may contain abundant typhoid 
bacilli for weeks and be little thought of as a source of 
infection. A persistent gonorrhcal vaginal infection 
may lead to a gonorrhceal endometritis, or salpingitis, or 
peritonitis, under suitable conditions. The staphylococci 
in the skin and the colon bacilli and pyogenic cocci in 
the fecal discharges may also be carried into the uterus 
and produce septic infection. 
