1. Clover sickness caused by Sclerotinia Trifoliorum is widely distributed in the American continent and western Europe; and in Britain it is often of considerable importance, especially in parts of East Anglia and Yorkshire. The severity of the disease is dependent upon the season, and in some countries very severe financial loss may result. 2. Most of the commonly grown legumes are subject to the disease, but they vary in their susceptibility. Peas affected with the disease have not been observed in the field although they succumb to artificial inoculation.