Escherich,1 in his study of intestinal bacteria in children, found that the small intestine during the intervals when only intestinal secretions are present is almost free from bacteria. Tissier2 examined the duodenal fluid obtained at autopsy from children dying without digestive derangement. He found in his cultures numerous colonies of B. coli and the enterococcus of Thiercelin, together with other organisms in small numbers. Experimental work on animals and observations on men undergoing surgical operations by Cushing and Livingood3 and by Kohlbrugge,4 has shown that the small intestine becomes practically germ-free in the absence of food material, and speaks of autosterilization of the small intestine. The factors on which this autosterilization depend are not definitely known.
In adults the bacteria of the duodenum have been studied by Gessner5 in eighteen cases in which autopsy was performed soon after death. Cases of digestive disturbance were