464 PATHOGENIC AEROBIC BACILLI 



a rather thin, circular layer forms about the point of puncture ; this has the 

 appearance of stearin ; later it becomes grayish- white and the margins are 

 marked by radiating lines. Upon the surface of nutrient agar a similar 

 growth occurs which has a pale-brown or reddish-gray color. Upon potato 

 in the incubating oven an abundant development occurs, forming a dry- 

 looking layer of a grayish-brown color and having irregularly notched mar- 

 gins. Upon blood serum an abundant, grayish- white growth of cream-like 

 consistence forms along the impfstrich; later this has a reddish gray color. 

 This bacillus grows to the bottom of the line of puncture in stick cultures, 

 and is no doubt a facultative anaerobic. 



Pathogenesis. Pathogenic for white mice and for guinea-pigs. 



105. BACILLUS ENDOCARDITIDIS CAPSULATUS. 



Obtained by Weichselbaum (1888) from thrombi and embolic infarctions 

 in the spleen and kidneys of a man who died from endocarditis with forma- 

 tion of thrombi. 



Morphology. Resembles Friedlander's bacillus, and is frequently sur- 

 rounded by a capsule, which may be stained ; also forms long, curved fila- 

 ments, in the protoplasm of which vacuoles may be observed in stained pre- 

 parations. 



Stains with the usual aniline colors, but not by Gram's method ; by 

 staining with fuchsin and carefully decolorizing with diluted alcohol the 

 presence of a capsule may be demonstrated. 



Biological Characters. Anaerobic, non-liquefying bacillus. Grows in 

 the usual culture media at the room temperature. 



In gelatin stick cultures development occurs along the line of puncture, 

 and on the surface as a rather thin, white, dry layer which resembles stearin. 

 In agar plates the superficial colonies are thin, about two millimetres in 

 diameter and gray in color ; under a low power the margins are trans- 

 parent and colorless, and the centre resembles the deep colonies; these are 

 very small and grayish-white in color ; under a low power the surface is 

 seen to be covered with tooth-like, projecting masses, the margin is dentate 

 and has a pale-yellow color, while the centre is yellowish- brown. 



Pathogenesis. Rabbits are killed by the injection of a considerable quan- 

 tity of a pure culture into the cavity of the abdomen or subcutaneously. 



10G. BACILLUS OF LESAGE. 



Obtained by Lesage (1887) from the green-colored discharges of infants 

 suffering from " green diarrhoea," and supposed to be the cause of this com- 

 plaint (?) According to Baumgarten, this bacillus is probably identical 

 with a well-known pigment-producing saprophyte the Bacillus fluorescens 

 non-liquefaciens. 



Morphology. Small bacilli with round ends, about 2.4 ju long and 0.75 to 

 1 H broad ; in old cultures may grow out into long filaments. 



Stains with the usual aniline colors, but not by Gram's method. 



Biological Characters. An aerobic, non-liquefying (slight liquefaction 

 in old cultures), motile bacillus. Forms spores. Grows slowly at the room 

 temperature in the usual culture media, more rapidly at 25 to 35 C. Upon 

 gelatin plates superficial colonies are formed which have irregularly dentate, 

 leaf-like margins and a smooth surface ; they produce a greenish color in the 

 gelatin. In gelatin stick cultures a thin, smooth, transparent, greenish 

 layer forms upon the surface, and in the course of four or five days the gela- 

 tin has acquired throughout a bright-green color. Upon potato a dark- 

 green layer is formed. The cultures have the odor of old urine. 



Pathogenesis. The injection of a considerable quantity of a pure culture 

 into the ear vein of a rabbit is said to have produced green diarrhoea, and 

 the same result was obtained by mixing cultures with the food of these ani- 

 mals. These results have not yet been confirmed by other investigators. 



