Intoxication is evident in a drained duodenal loop whether it opens externally or into the jejunum and may be associated with more or less immunity which can be demonstrated after a period of days. Intoxication with a closed duodenal loop is identical whether the loop is left empty at operation or filled with a lethal dose of loop fluid. This again emphasizes the fact that absorption of the poison is essentially from the mucous membrane rather than from the contents of the closed loop. The intoxication of a closed duodenal loop is not modified by the presence of bile, pancreatic juice, or gastric secretion. Cessation of the normal flow of intestinal fluids which bathe the mucous membrane may be essentially responsible for the perverted activity of the mucosa and secretion of a poisonous material into the blood. Animals may be slightly more resistant to closed or drained loops during the warm months, which may be explained by the increased loss of body heat in the colder months. This indicates that cases of acute intestinal intoxication with subnormal temperature may be benefited by a generous supply of artificial heat.