b, a pair of bacilli actively growing and dividing.

p, a rodlet in this condition (but divided into four segments) after treatment with alcoholic iodine solution.

c, d, e, f, successive stages in the development of the spores.

r, a rodlet segmented in four, each segment containing one ripe spore.

g1, g2, g3, early stages in the germination of the spores (after being dried several days);

h1, h2, k, l and m, successive stages in the germination of the spore.

Fig. 7.—Bacillus anthracis. (After Koch.)

A. Bacilli mingled with blood-corpuscles from the blood of a guinea-pig; some of the bacilli dividing.

B. The rodlets after three hours' culture in a drop of aqueous humour. They grow out into long leptothrix-like filaments, which become septate later, and spores are developed in the segments.