Glycerin-Agar, except for primary cultures, is the best medium upon which to grow the bacillus, particularly if a little glucose be added. The growth begins as on serum, but the colonies are both larger and more numerous. They rapidly become confluent, and form a thick, whitish, dry, rough, scaly layer. After being subcultivated a few times the growth becomes very abundant, moist, and greasy. When old the growth has a reddish tint. On bouillon containing glycerin and glucose the growth takes place in the form of a pellicle, which is dense, creamy white, dry, and very friable. The fluid remains clear, although the pellicle may eventually break in pieces and fall to the bottom of the tube. The organism will grow also on glycerinized potato and on Dorsett's egg-medium. This latter consists of the whites and yolks of eggs mixed, coagulated, and sterilized by the intermittent method. Gelatin cannot be used, as it melts at the temperature (370 to 380 C.) required for growth. During incubation the tubes should be closed, so as to prevent evaporation.