The ordinary pickle bacteria, therefore, would not multiply as rapidly in the interior of the hams and would not find their way into the bone marrow as soon as would a strictly anaerobic organism. Pure cultures of the sour-ham bacillus, recovered from the meat and bone marrow of the injected hams, were compared with cultures of the original bacillus used for inoculating the hams, and were found to be identical. Furthermore, the bacillus with which the hams were injected was recovered from the injected hams at points far removed from the original point of injection, showing that the organism had multiplied and extended throughout the bodies of the hams and that it was clearly responsible for the souring which the hams had undergone. Sound hams from tierces 2 and 4 were examined bacteriologically in the same manner as the injected hams, and some of the cultures showed the ordinary pickle bacteria, but in not a single instance did egg-pork cultures yield a sour odor, and in no case could the sour-ham bacillus be demonstrated in any of these hams. Microscopic sections and teased preparations of the muscle fibers in salt solution were prepared from several of the sour hams in this experiment, and these preparations showed the same histological changes and the same distribution of bacilli as noted in the natural sours. In Plate III, figures 1 and 2, sections are shown of artificially soured hams, that is, hams which were artificially soured by injections of culture; and if these figures be compared with the sections made from hams which had undergone spontaneous souring (see Pl. II, figs. 1 and 2) the similarity in the form and distribution of the bacilli will be at once apparent. [Illustration: BUL. 132, BUREAU OF ANIMAL INDUSTRY, U. S. DEPT. OF AGRICULTURE. PLATE III. FIG. 1.—SECTION THROUGH MUSCULAR TISSUE OF ARTIFICIALLY SOURED HAM, SHOWING DISTRIBUTION OF BACILLI BETWEEN THE MUSCLE FIBERS, WHICH ARE SHOWN IN CROSS SECTION. THE DARK LINES AND MASSES BETWEEN THE MUSCLE FIBERS REPRESENT CLUMPS OF BACILLI. (Pen-and-ink drawing made with camera lucida from section stained by the Gram-Weigert method to show bacteria. × 85.)] FIG. 2.—SECTION THROUGH MUSCULAR TISSUE OF ARTIFICIALLY SOURED HAM, SHOWING INDIVIDUAL BACILLI BETWEEN THE MUSCLE FIBERS, WHICH ARE CUT LONGITUDINALLY. (Pen-and-ink drawing made with camera lucida from section stained by the Gram-Weigert method to show bacteria. × 320.)]