NOT DESCRIBED IN PREVIOUS SECTIONS. 473 



Biological Characters. An aerobic, liquefying, motile bacillus. Does 

 not form spores. Grows in the usual culture media at the room temperature. 

 In gelatin stick cultures a sac-formed liquefaction occurs and a yellow de- 

 posit is seen at the bottom of the liquefied gelatin ; gas bubbles are given off 

 from the culture. Upon the surface of agar development occurs along the 

 line of inoculation in the form of flat, grayish-yellow, transparent, varnish- 

 like plaques. Upon potato, after several days, a brownish, shining, moist, 

 transparent film is formed. Upon the surface of blood serum smooth, 

 yellowish, transparent colonies are formed, under which the blood serum is 

 softened, allowing these to sink below the surface. 



Pathogenesis. Pathogenic for mice and for guinea-pigs, which die in 

 from one to two days. An abscess forms at the point of inoculation, which 

 is covered with a dry, retracted crust. 



128. BACILLUS OF TRICOMI. 



Obtained by Tricomi (1886) from a case of senile gangrene. 



Morphology. Bacilli with round ends, about three ju long and one 

 thick, solitary o- in pairs ; sometimes one end of a rod shows a club-shaped 

 thickening. 



Stains with the usual aniline colors and by Gram's method. 



Biological Characters. An aerobic, liquefying, non-motile bacillus. 

 Forms spores. Grows in the usual culture media at the room temperature 

 better at 37 C. 



Upon gelatin plates, at the end of twenty-four hours, the colonies are 

 spherical, finely granular, and of a dirty-yellow color ; after from thirty-six 

 to forty-eight hours liquefaction of the surrounding gelatin occurs. In gela- 

 tin stick cultures closely crowded, small, white colonies are formed along 

 the line of puncture ; at the end of forty-eight hours liquefaction com- 

 mences in funnel form, with formation of an air bubble above like the 

 cholera spirillum; later the entire gelatin is liquefied and becomes trans- 

 parent, while a dirty-white collection of bacilli is seen at the bottom of the 

 tube. Upon the surface of agar a white layer with irregular margins is 

 formed, which later extends over the entire surface as a homogeneous, rather 

 thin membranous film. ~Upon potato, at 37 C., dirty-white, milky colonies 

 are formed, which later become confluent. Upon blood serum the growth is 

 similar to that upon agar. 



Pathogenesis. The subcutaneous injection of one-half to one cubic centi- 

 metre of a gelatin culture is said by Tricomi to produce in rabbits and in 

 guinea-pigs a gangrenous process resembling senile gangrene in man. The 

 subcutaneous connective tissue is infiltrated with a foul-smelling serum, the 

 muscles are soft and gray, and a portion of the skin has a mummified ap- 

 pearance. The gangrene extends over the abdomen, and death occurs in 

 guinea-pigs in two to three days, in rabbits after four days, in house mice 

 at the end of twenty-four hours ; white mice are said to be immune. 



129. BACILLUS ALBUS CADAVERIS. 



Obtained by Strassmann and Strieker (1888) from the blood of two cada- 

 vers four days after death. 



Morphology. Bacilli about two and one-half >" long and 0.75 ft broad; 

 also grow out into filaments of six ft or longer. 



Stains with the usual aniline colors andby Gram's method. 



Biological Characters. An aerobic, liquefying, motile bacillus. Spore 

 formation not observed. Grows in the usual culture media at the room tem- 

 perature. In gelatin plates small, spherical, yellowish colonies are formed 

 during the first twenty-four hours ; later a radiating outgrowth occurs from 

 the periphery, and liquefaction of the gelatin takes place. In gelatin stick 

 cultures liquefaction begins within forty-eight hours, and forms a long fun- 

 nel, at the opening of which is a cavity containing air ; the liquefied gela- 



