A USEFUL. Pamphlet entitled "Verticillium on Mushrooms"has recently appeared from the Midlands GAuplffublications (Yaxley, Peterborough, 55 $0 946. net). Fred C. Atkins, honorary secre-tary of tne Mushroom Growers' Association, reviews the history of the disease, its symptoms and control. Verticillium Malthousei is the causal fungus; it may be soil-borne, or carried by flies. The best method of control appears to be fumigation of mushroom houses by formalin vapour generated by mixing potassium permanganate and 40 per cent formaldehyde. An appendix contains extracts from “Control of Mushroom Diseases ssand Weed Fungi” by W. S. Beach (Bull. 351, Pa. Agric. Exp. Sta., 1937). Infection by Verticillium is favoured by high relative humidity, and an additional measure of control lies in spraying a diseased area of the bed, after removal of the good mushrooms, with Bordeaux mixture. A further appendix is a reprint of the original paper by W. M. Ware, which describes V. Malthousei as a new species Ann. Bot., 47, No. 188; Oct. 1933). This gives cultural details, thermal reactions, the results of inoculation tests, and outlines methods for the examination of diseased mushrooms for the disease. There are six excellent photographs, and the pamphlet is further enriched by a coloured plate prepared by McG. Bulloch. This shows symptoms of the soil-borne and insect-borne phases of the disease.