Concretions of varying appearance, density and structure are often found in the human appendix, both with and without inflammatory changes in the organ itself. Owen T. Williams1 has made a particular study of these, calling attention to the fact that the appendix seldom contains fecal material, and that the usual appendiceal stones are not fecal concretions but concentrically laminated concretions, often larger than the lumen of the appendix between the stone and the cecum, and therefore presumably formed by secretion from the wall of the appendix. According to him, the typical appendix concretion is almost white, with a smooth cut surface resembling soap, whereas fecal concretions are pigmented and have a greasy appearance. Like the intestinal sand, they contain fats soluble in ether and soaps insoluble in ether. He analyzed three appendix concretions, and found material soluble in ether to the amount of 14.97, 16.2 and 7.1 per cent.,