BULLETIN JSTO. 10 of the Mushroom Growers' Association (Yaxley, Peterborough. 2s. 6d. net) contains a brief note by F. C. Atkins and C. J. La Touche on Pseudobalsamia microspores, an ascomycete which may compete with the mushroom on commercial beds. It is almost certainly introduced with the surface soil and so can possibly be eliminated with care. Boards and the house-structure should be sterilized and flies kept down, as they spread the trouble. The same bulletin contains reprints of Dr. W. M. Ware‘s paper on"Clitopilus cretatus as an Invader of Mushroom Beds"(Gard. Chron., May 18, 1935),-and Dr. W. F. Bewley‘s work on mushroom casing soil (Cheshunt Exp. Sta. Ann. Rep., 1946). A separate leaflet lists useful volumes on mushroom culture in the Association‘s library.