Intestinal amebiasis due to various degrees of ulceration of the large bowel and rectum following infection with Endameba histolytica is a very common ailment throughout those parts of the Caribbean littoral where the United Fruit Company maintains hospitals. A survey of the reports of the medical department of the company for the last ten years shows that the acute phase of this infection, amebic dysentery, is prevalent and very generally distributed; and where this is true there is inevitably a large proportion of infection, which, even though dysentery is not active, produces all manner of symptoms referable to the gastro-intestinal tract, and at times abscess of the liver and even more serious complications. Following a small, and local outbreak of amebic dysentery in 1925, in Santa Marta, Colombia, confined mostly to American employees, a survey was made by Kofoid, Swezy, Boyers and James1 which uncovered approximately 60 per cent