Explanation of Plate III. FIG. I.-Culture of bacillus in bouillon on eleventh day (original culture). Carbol-fuchsin; water; 20 per cent. nitric acid. Winkel Homog. Immersion 1/14, ocular 4. FIG. 2.-Same culture as Fig. I; five days later, showing hull. Gram's Method, Winkel Homog. Immersion 1/14, ocular 4. FIG. 3.-Second generation on gelatine; three days old. Carbol- fuchsin; water, and subsequent 20 per cent. nitric acid. Winkel Homog. Immersion 1/14, ocular 4. FIG. 4.-Second generation on Agar from first generation on Agar; two days old. Carbol-fuchsin; water, and subsequent 20 per cent. nitric acid. There is a hull round a few bacilli, and being drawn in water, these appear rather large. FIG. 5.-First generation on Agar from original; three days old, showing the commencing grouping together of the bacilli owing to the development of a mucin (?) hull. Magnification as above. FIG. 6.-A small colony of first generation on Agar; five days old, showing peculiar grouping of bacilli into heaps very comparable to the grouping in tissues. Methyl Blue. Winkel 1/14, ocular 3. FIG. 7.-Culture of bacillus resembling the vacuolated bacilli figured by Neisser. Magnification as above. FIG. 8.-Appearance exhibited by bacilli described by Neisser as Kugel Bacteria. Magnification as above. All the figures were drawn with the Camera Lucida.