THE Mushroom Growers' Association is a body formed by a particular section of the horticultural industry in order to solve its own pressing problems. Some interesting features relating to mushroom diseases have recently appeared in the Association‘s Bulletin (Nos. 11 and 12, April and July, 1948). ‘Cobweb', caused by overgrowth of beds by Dactylium species, is briefly described by Fred C. Atkins. The control of ‘bubble', caused by the fungus Mycogone pemiciosa, is outlined by Edmund B. Lambert. He regards as necessary a complete programme : burning sulphur and fumigating with formalin before the mushroom houses are used, taking water direct from uncontaminated deep wells, attaining a temperature of 120° F. for 48 hr. in the final fermentation of manure and casing soil, and general methods of hygiene. A new leaflet of the Association (No. 3) describes the general characters of Mycogone disease. A detailed account of the invasion of mushroom beds by truffles is contributed by A. M. Kligman, and, as control of most mushroom diseases involves rigid methods of hygiene, the necessary measures are considered in detail by R. L. Edwards and C. J. la Touche.