730 ADDITIONAL SPECIES OF 



rapidly in the usual culture media at the room temperature also at 38 C. 

 On gelatin plates small, white, spherical colonies sometimes slightly yel- 

 low; the superficial colonies are elevated above the surface of the gelatin. 

 In gelatin tubes an abundant growth occurs along the line of puncture and 

 slowly extends upon the surface. In. cultures from the spleen of an inocu- 

 lated animal the growth upon the surface is less marked. On agar a thin, 

 white layer is formed. On potato a light-brown, moist growth. In recent 

 cultures from the spleen of an inoculated animal the growth upon potato 

 may be invisible. Grows abundantly both in Parietti's solution and in Uf- 

 felmann's gelatin. 



Pathogenesis. Pathogenic for rats, mice, guinea-pigs, and rabbits. 



482. BACILLUS VENENOSUS BREVIS. 



Obtained by Vaughan from water. 



Morphology. Short, thick bacilli, about twice as long as broad; in old 

 cultures grows out into threads. 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying, actively motile bacillus. Spore formation not mentioned. 

 Grows rapidly in the usual culture media at the room temperature also at 

 38 C. On gelatin plates forms small, round colonies with concentric rings: 

 the deeper colonies are generally yellowish or brown ; the surface colonies 

 are elevated and spread but little. In gelatin tubes grows along the line of 

 puncture and spreads slowly upon the surface, finally reaching the sides of 

 the tube. Upon agar a thin, white layer is formed. On potato a thick and 

 moist, light-brown growth. When kept for fourteen days or longer at 40 C. 

 there is an invisible growth upon potato. Grows abundantly in Parietti's 

 solution and slowly in Uffelmann's gelatin. 



Pathogenesis. Pathogenic for rats, mice, guinea-pigs, and rabbits. 



483. BACILLUS VENENOSUS INVISIBILIS. 



Obtained by Vaughan from water. 



Morphology. A slender bacillus with rounded ends, from two to four 

 times as long as broad. 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying, motile bacillus. Spore formation not mentioned. Grows slowly 

 in the usual culture media at the room temperature also at 38 C. On gela- 

 tin plates small, granular, yellowish colonies are developed ; the superficial 

 colonies are coarsely granular and very irregular in size and outline. In 

 gelatin tubes grows slowly both on the surface and along the line of punc- 

 ture ; scarcely visible at end of three days. On agar a very thin, white 

 growth. On potato the growth is sometimes invisible; on some potatoes a 

 light-brown layer may be developed. Grows well both in Parietti's solution 

 and in Uffelmann's gelatin. 



Pathogenesis. Pathogenic, but in less degree than Bacillus venenosus. 



484. BACILLUS VENENOSUS LIQUEPACIENS. 



Obtained by Vaughan from water. 



Morphology. Bacilli with rounded ends, one and one-half to twice as 

 long as broad. 



Biological Characters. An aerobic and facultative anaerobic, lique- 

 fying, motile bacillus. Spore formation not mentioned. Grows rapidly in 

 the usual culture media at the room temperature also at 38 C. On gelatin 

 plates the deep colonies are finely granular, sphei'ical, and yellowish in 

 color; superficial colonies elevated and spread over the surface. In gelatin 

 tubes grows abundantly along the line of puncture and spreads slowly over 

 the surface; liquefaction commences in from four to six weeks. On agar a 



