526 PATHOGENIC AEROBIC BACILLI 



liquefaction can be discerned around the colonies, and at the end of about 

 ten days the gelatin is entirely liquefied. In gelatin stick cultures a scanty 

 growth is seen along the line of inoculation at the end of twelve hours ; the 

 growth upon the surface is rapid, and liquefaction commences at the end of 

 twenty-four hours. Upon agar, at 37 C. at the end of eighteen hours, a thin 

 granular layer is seen, which consists of small, pale-gray colonies. In agar 

 stick cultures a scanty growth occurs along the line of puncture, which does 

 not increase after thirty-six hours. Upon the surface the growthis abundant, 

 forming, at the end of five days a tolerably thick grayish-white layer. No 



growth occurs upon potato at the room temperature, but at 37 C. a tolera- 

 ly thick, sticky layer of a grayish-white color is developed in three or four 

 days. In bouillon, at 37 C., the medium is clouded at the end of twelve 

 hours, and a thin pellicle is seen upon the surface at the end of thirty-six 

 hours ; this falls to the bottom when the tube is slightly agitated. At the 

 end of four days development has ceased, and the bouillon is again transpar- 

 ent, while a flocculent deposit is seen at the bottom of the tube. The bouillon 

 gives off a penetrating odor, like that of burnt milk. The same odor is given 

 off from cultures in milk, which is peptonized by the action of the bacillus. 

 At the end of twenty days, at 37 C., the entire contents of the tube have be- 

 come transparent. 



Pathogenesis. Produces a fatal infectious disease in fish ("gold carp' 1 ) 

 when inoculated beneath the skin ; also pathogenic for mice and for guinea- 

 pigs. 



174. BACILLUS PYOGENES FILIFORMIS (Flexner). 



Obtained by Flexner (1895) from the interior of the uterus and from an 

 exudate in the pericardial and pleural cavities, of a rabbit which died on the 

 fifth day after parturition! 



Morphology. Pleomorphous cocci-like forms, short or long bacilli, and 

 long threads are seen in cover slips prepared from the exudate. "Very few 

 of the bacilli stain regularly ; for the most part brightly stained spots appear 

 between stained areas. An outer membrane always stains, enclosing the 

 stained dots in a colorless ground. The threads, as a rule, present delicate, 

 sinuous, and wavy outlines ; the short forms are straight with rounded ends." 



Biological Characters. All attempts to cultivate this bacillus in the 

 usual media, either in the presence of oxygen or in an atmosphere of hydro- 

 gen, proved unsuccessful. But successive cultures were made by inoculations 

 in the pleural cavity of rabbits a bit of pleural exudate suspended in bouil- 

 lon was used for this purpose. The bacillus was also propagated upon the 

 lungs, heart, uterus, and kidney of healthy rabbits. The organs were re- 

 moved with great care to prevent contamination and placed in sterilized test 

 tubes. Transplantations from these cultures were only successful for one or 

 two generations. Better results were obtained by cultivating the bacillus 

 upon the one-third to one-half grown foetuses of rabbits. 



Pathogenesis. " Considerable variations were observed according as the 

 inoculations were made into the pleural cavity, the peritoneal cavity, the sub- 

 cutaneous tissue, beneath the dura mater, or directly into the circulation. 

 The inoculations gave positive results in all cases except a few, in which they 

 were made subcutaneously. The death of the animal occurred soonest when 

 inoculation was made beneath the dura mater. A small portion of the skull 

 was trephined, care being taken to exclude rxt raucous microorganisms, and 

 a drop of the pleural fluid or a speck of the librinous oxiidato \vas introduced 

 beneath (lie membranes, care, being 1 taken not to injure the brain. These 

 animals, which quickly recovered from the effects of the operation, died on 

 an average about twelve hours after the inoculation. . . . 



" The pleural inoculations were followed by death, as before stated, in ev- 

 ery instance, the death of the animal occurring upon the third or fourth day. 

 The appearances presented at the autopsy were for the most part an exact 



