NON-PATHOGENIC BACILLI. 071 



which is frequently opalescent ; an abundant development occurs along the 

 line of puncture, consisting 1 of a series of spherical colonies : liquefaction oc- 

 curs after a considerable time four weeks. Upon the surface of agar a 

 thin, grayish-white layer is developed along the iinpfstrich. Upon potato a 

 tolerably abundant slimy, yellowish-green layer. 



361. BACILLUS IMPLEXUS (Zimmermann). 



Found in the Chemnitz water supply. 



Morphology. Bacilli with blunt ends, about 2.5 ju. long and 1.15 // broad; 

 form long, jointed filaments. 



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

 Forms oval spores about 1.6 n long and 0.95 /u thick. Grows at the room 

 temperature more quickly at 30 C. Upon gelatin stick cultures, at the 

 end of twenty-four to thirty-six hours, whitish, punctiform colonies become 

 visible; under a low power these are seen to be granular, opaque, and ir- 

 regular in outline more transparent toward the margin ; under a higher 

 power (1 : 175) filaments are seen which are interwoven ; these grow out 

 from the margins and again become contorted and interlaced ; at the end of 

 three days the round colony sinks into the liquefied gelatin and appears then 

 as an interlaced mass of fine white filaments. In gelatin stick cultures 

 growth is visible along the line of puncture at the end of twenty -four hours, 

 and at the end of seventy-two hours bundles of short threads radiate into 

 the gelatin in all directions; liquefaction soon occurs, which quickly reaches 

 the walls of the test tube at the surface; a thick, white layer forms upon the 

 surface of the liquefied gelatin, and it is filled below with white flocculi. 

 Upon the surface of agar a tolerably thick, white layer is formed which has 

 a dull, shagreen-like surface and soon becomes wrinkled. Upon potato a 

 yellowish or greenish- white, felt-like layer is formed. 



362. BACILLUS PUNCTATUS (Zimmermann). 



Common in the Chemnitz water supply. 



Morphology. Bacilli from 1 to 1.60 /i long when in rapid multiplica- 

 tion and 0.77 f* broad; solitary, in pairs, or in chains containing several 

 elements. Do not stain readily with the usual aniline colors. 



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

 Spore formation not observed. Grows rapidly at the room temperature 

 still better at 30 C. Upon gelatin plates the colonies, on the third day, al- 

 ready have a diameter of twelve millimetres and have caused a saucer- 

 shaped liquefaction of the gelatin ; in the grayish-blue liquid whitish, punc- 

 tiform collections of bacteria are seen, which are often united with each 

 other by whitish strings. In gelatin stick cultures liquefaction occurs in . 

 stocking shape; the liquefied gelatin is uniformly clouded, and an abundant 

 white deposit accumulates at the bottom of the tube. Upon the ' surface of 

 agar a delicate, gray, glistening layer with a perfectly smooth surface is 

 developed. Upon potato an abundant brownish or flesh-colored layer soon 

 extends over the entire surface; gradually this acquires a darker hue. 



363. BACILLUS RADIATUS AQUATILIS (Zimmermann). 



Found in the Chemnitz water supply. 



Morphology. Bacilli about 0.65 n broad and from 1 to 0.5 fj. long. 



Biological Characters. An aerobic, liquefying bacillus. The shortest 

 rods only exhibit slight movements. Spore formation not observed. Grows 

 best at the room temperature Upon gelatin plates, at the end of two days, 

 irregular, bluish-white colonies are seen, which often have a white point in 

 the middle; under the microscope the colonies have a root-like appearance, 

 being surrounded by simple and branching mycelial-like offshoots; at the 



