. Diseases of bees. Bees. 14 BVLLETIN 810, U. S. DEPAET-MENT OF AGRICULTURE. cular and uniform in outline. The color is bluisli by transmitted and grayish by reflected light. Under a two-thirds objective they are a light brown, and are finely granular near the periphery, but more coarsely granular near the center. Morphology.—The rod (fig. 4; PI. VII, C) is smaU and slender with slightly rounded ends, occurring usually in pairs or singly. It is nonmotile and no spores are produced. Staining properties.—It is stained easily and uniformly with the ordinary aniline stains and is Gram-negative. Ox
. Diseases of bees. Bees. 14 BVLLETIN 810, U. S. DEPAET-MENT OF AGRICULTURE. cular and uniform in outline. The color is bluisli by transmitted and grayish by reflected light. Under a two-thirds objective they are a light brown, and are finely granular near the periphery, but more coarsely granular near the center. Morphology.—The rod (fig. 4; PI. VII, C) is smaU and slender with slightly rounded ends, occurring usually in pairs or singly. It is nonmotile and no spores are produced. Staining properties.—It is stained easily and uniformly with the ordinary aniline stains and is Gram-negative. Oxygen requrenveiits—Growth is better in the presence of air than in anaero- bic conditions. Bouillon.—Grov^th takes place slowly, producing a uniform cloudiness with no pellicle. After a week or more a somewhat viscid sediment is present. Sugars.—Growth in the sugar media is slow, variable, and never luxuriant. Both arms may be clouded. Glucose or levulose when added improves a medium. Fermentation with gas does not take place in any of the sugars. A noticeable amount of acid is formed when glucose and levulose are used, the other sugars being less affected. A 1 per cent honey solution supports a moderate growth. Brood filtrate as a rule improves media. Milk.—In plain and litmus milk no changes are visible. Potato.—Growth on potato is slow. When present, the culture is for the most part grayish in color. Gelatin stab.—A bluish gray growth appears slowly along the line of inocula- tion. No liquefaction follows. Pathogenesis.—No ill results are ob- served when cultures of Bacterium eury- dice are fed to healthy colonies of bees. A rabbit inoculated subcutaneously with a pure culture proved to be refractory. BACILLUS ORPHEUS The name Bacillus orpheios was given to an interesting species occa- sionally encountered in European foulbrood (15). In one instance the species was found very widely distributed in an apiary in which FIG. s.—Baoiiius orphens: Spore for- he
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