SPUTUM SEPTIC^MIA. 261 



perature as 18 C. From 42 C. on, the development 

 is checked. 



Under most favorable conditions the growth is very 

 slow. It grows as well without as with oxygen. It is, 

 therefore, one of the facultative anaerobic forms. 



The most successful eiforts at the cultivation of this 

 organism are those seen when the agar-agar-gelatin 

 mixture of Guarniari is employed. (See this medium.) 



It may be stained with the ordinary aniline staining 

 reagents. For demonstration of the capsule the method 

 of Gram gives the best results. (See Stainings.) 



This organism is conspicuous for the irregularity of 

 its behavior when grown under artificial conditions; 

 usually it loses its pathogenic properties after a few 

 generations ; but again this peculiarity may be retained 

 for a much longer time. Not rarely it fails to grow after 

 three or four transplantations on artificial media, though 

 at times it may be carried through many generations. 



Inoculation into animals. The results of inoculations 

 with pure cultures of this organism are also conspicuous 

 for their irregularity. Most commonly when the organ- 

 ism is of full virulence the form of septicaemia just de- 

 scribed is produced, but at times it is found to be totally 

 devoid of pathogenic powers ; between these extremes 

 cultures may be obtained possessing all variations in the 

 intensity of their disease-producing properties. The 

 principal pathological conditions that may be produced 

 by this organism by inoculations into animals, accord- 

 ing to the degree of its virulence, are acute septicaemia, 

 spreading inflammatory exudations, and circumscribed 

 abscesses. All three of these conditions may sometimes 

 be produced by inoculating the same cultures into rabbits 

 in varying amounts. 



12* 



