Bacillus CEdematis Maligni, No. II, Novy (1893). 



Origin. — From guinea-pigs inoculated with milk nuclein obtained 

 from casein by digestion with artificial gastric juice. 



Form.— In the animal body it occurs usually in single rods, 4-5 

 times as long as wide; may also occur in short threads. On artificial 

 media it develops as straight or bent rods, sometimes forming peculiar- 

 ly twisted threads. The contents are often granular, and show a 

 bright body at one end. 



Motility. — Possesses a slight swaying motion, which is often 

 absent. Has lateral flagella, and in pure culture, as well as in the 

 animal, it gives rise to giant whips which may attain a length of 

 40-50-72 microns (Fig. 7, p. 39). 



Sporulation. — Spore formation not observed. 



Anilin dyes. — Stain readily. Gram's method applicable. 



Growth. — Depends upon the vitality of the organism. When 

 taken from an animal it grows rapidly. 



Plates.— Oa glucose agar good colonies develop in 2-3 days at 37°. Show a very 

 irregular, fibrillated border, and often give rise to gas bubbles. May contain giant' whips. 



Stab culture, — Develops only in the lower part of the tube. In glucose agar having 

 proper alkalinity, it develops rafjidly forming a plainly visible growth along the line of 

 inoculation; the agar is soon torn into several parts by the gas that is produced. Cultures 

 soon die out. 



S<r«fl/fc £«/<««.— Growth on glucose agar only when otygen is completely excluded. 

 It forms a White film which spreads over the surface. On acid agar involution forms develop. 



Bouillon.— kn excellent growth develops which in 24 hours settles to the bottom as a 

 "loose, flocculent sediment; the liquid above 'becomes clear— distinction from M. edema and 

 S. anthrax bacilli. 



Glucose gelatin, colored with litmus.— Is liquefied and acid is produced— the litmus 

 is reduced and then turned red. 



Oxygen requirements.— IsanoftZigaiweariaerobe. Grows in vacuum, 

 hydrogen, nitrogen, carbonic acid, illuminating gas. 



Temperature.— Does not grow below 25°. Optimum temperature 

 about 39°. Can withstand freezing for 24 hours. 



Behavior to gelatin. — Liquefies. 



Aerogenesis. —In alkaline media gives rise to gases. Volatile 

 acids, as butyric acids, etc., are formed in artificial culture and also 

 in the body of rabbits. 



Attenuation. —Cultures left in hydrogen, or exposed to light, lose 

 their virulence. It is not attenuated when kept in the dark or when 

 frequently passed through animals. Lost virulence can be reconsti- 

 tuted by inoculation with a "mixed" culture containing Proteus 

 vulgaris. 



Immunity. — Not conferred by a non-fatal inoculation, or by old, 

 weakened cultures, or by the serous exudate of the pleural cavity. 



Pathogenesis. — Subcutaneous injection of i c.c. of hydrogen 

 bouillon cultures kills guinea-pigs, rabbits, white rats, white mice, 

 •doves, in 12-24 hours. Marked subcutaneous edema present; serous 

 exudates in thoracic and abdominal cavities. Cover-glass prepara- 

 tions made from the subcutaneous tissue or serous surfaces, as peri- 

 toneum, shows usually enormous numbers of bacilli, and frequently 

 giant whips are also present. The latter are visible as colorless spirals. 



Diagnosis. — The morphological characteristics distinguish it 

 readily from malignant edema and from symptomatic anthrax. 



302 



