The fluke is a parasitic worm which inhabits the duodenum and biliary passages in man. It is very common in sheep, occasioning what is known as "liver-rot," a disease from which many thousands of sheep often die in a single epidemic. In Egypt a variety of the parasite is found which gives rise to a very formidable disease. In this country, fortunately, the parasite is so seldom met with in man that it is of no medical importance.