largely in milk, the organisms soon revert to the non-granular type if cultivated on agar. By the use of the Gram-Weigert stain organisms from a several-days-old culture on beer-wort-agar gave an interesting reaction. The bacillar threads are in places Gram-negative, in others Gram-positive, and bear small club-like swellings (see Fig. 14). Results similar to these were also obtained with cultures of _Bacillus matzoon_ (Weigmann and Grübner) and also with _Bacillus acidophilus_. Neisser's method of staining failed to give such good effects by the examination of fresh maya, as did an alcoholic aqueous solution of methylene blue in showing up the granules of the organisms. Again, Grixoni[74] found, but did not isolate, a similar granule-forming organism (_Bacterium sardous_) in Sardinian gioddu. As already mentioned in the description of leben, Rist and Khoury found a long bacillar lactic ferment (_Streptobacillus lebenis_) which also exhibited the irregular greyish white hairy colonies and high optimum temperature characteristic of this group. On account of the similarity in form, staining reactions, temperature requirements, and cultural growth of the organisms described by Emmerling, Düggeli, Weigmann, Grixoni, and Rist and Khoury, Kuntze is inclined to regard them as belonging to one single group of lactic ferments. According to him the granule formation is rather variable, and may be induced or suppressed by cultural methods. Not only do organisms of this group produce far more acid than the normal lactic bacteria; they are also more resistant to acid, and are able to develop in milk to which 0.5 per cent. hydrochloric acid has been added. A comparatively high percentage of alcohol seems to encourage growth, and this was obtained in milk containing 4 per cent. alcohol. This would no doubt tend to explain the phenomenon observed by Kuntze that milk is not so rapidly fermented by organisms of this group as when cultures of diplococci and yeasts are added. Since organisms of this group would seem to be widely distributed, the question of their natural habitat arises. Luerssen and Kühn were unsuccessful in their search for such organisms in Königsberg milk, but Leichmann records the occurrence of a long bacillus (_Bacillus lactis acidi_) in milk that had spontaneously soured at 112° to 120° F. This organism, too, showed characteristic growth on agar media, and produces lævo-rotatory lactic acid. The examination of calves' stomachs showed, according to Kuntze, only occasional long bacilli, but inoculation of sterile milk and incubation at 100° F. with repeated over-inoculation gave a culture showing the characteristic granule reaction (see Figs. 18 and 20). Although plate cultures made direct from calves' stomachs do not exhibit the regular contours generally shown by the granule bacillus, yet this growth may be induced by preceding cultivation in lactose bouillon to which 0.5 per cent. acetic acid has been added. A similar organism,