THE deep brown or sepia-coloured spore dust often seen on cereals, and arising from the presence of a fungoid growth, is sufficiently rich in colour to become useful as a pigment for the artist. The colour obtained from smutty oats, for example, is of a deep rich umber shade, sometimes approaching to sepia in tone. Satisfactory experiments were made regarding its fastness to light and atmospheric influences. Specimens of the pigment painted on paper as a water-colour were exposed to direct sunlight for several months; and after this rather severe trial, they were compared with unexposed duplicate specimens. Little change in the appearance of the colours was apparent. With mild diffused daylight—such as that of an ordinary, well-illumined room—the colour remains quite fast and unaltered. Experiments were made on a small scale with oat smut pigment, and the results seemed highly satisfactory. Several grams of the dry spore dust were collected from smutty oats, and it was found that twelve heads of such oats yielded six grams of the brownish-black dust. This powder, being of a dry and light nature, had first to be moistened with a few drops of alcohol, then mixed with gum and water to form a water-colour pigment. In its deepest tones it is of a fine sepia shade, deepening to a brown-black. On diluting with water or Chinese white, pleasing tints of a flat brown, of the pheasant-egg cast, are obtained. This colour has met with approval among artist friends to whom it was shown.