The writer proposes a modification of Muir''s method. Growth from agar slants 1-3 days old is suspended in sterile distilled water 20-30 minutes-at room temperature. A large loopful of the suspension is spread with unsized paper over a specially cleaned slide. The film is mordated for 10 minutes at room temperature in a mixture of the following freshly mixed solutions (1) potash alum, saturated aqueous solution, 5 cc; tannic acid, 20% aqueous solution, 2 cc. (a few drops of chloroform must be added if a large quantity is made up); HgCl2, saturated aqueous solution, 2 cc. (2) Basic fuchsin, saturated alcoholic solution, 0.4 cc. After washing, the films are stained 5-10 minutes with Ziehl''s carbol fuchsin.