398 



BACILLUS ^ROGENES CAPSULATUS 



but only under anaerobic conditions ; the optimum temperature is that 

 of the body, growth at the room temperature being comparatively slow. 

 In a puncture culture in agar there is an abundant whitish line of growth 

 with somewhat indented margin ; the individual colonies are white and 

 of rounded or oval form. There is practically no liquefaction of gelatin, 

 though this medium becomes somewhat softened around the growth. 

 In all cases there is a tendency to abundant evolution of gas in the 



cultures, and this is especi- 

 ally marked when ferment- 

 able sugars are present. 



The organism appears to 

 be the most frequent cause 

 of rapid gaseous develop- 

 ment in the blood and 

 organs post mortem, this 

 depending upon an invasion 

 of the blood immediately 

 before death. In such cases, 

 even within twenty - four 

 hours under ordinary con- 

 ditions, large bubbles of 

 gas may be present in the 

 veins, and the organs may 

 be beset with gas-contain- 

 ing spheres of various sizes ; 

 the liver is usually the 

 organ most affected, and its 



appearance has been com- 

 FIG. 133. Bacillus aerogeues capsulatus ; d to tbat of Gruyere 



film preparation from bone- marrow in a c } ieese The invasion by 

 case where gas-cavities were present in the this organism is met with 



from time to time in puer- 

 peral cases, and also in 



connection with ulcerative or gangrenous conditions of the intestine ; 

 the bacillus is also found not infrequently in 'the peritoneum in 

 cases of perforation. Although the striking changes in the organs 

 are due to a post-mortem development of the bacillus, there is no 

 doubt that its entrance into the blood stream often hastens death, 

 and may in some instances be the cause of it. As already stated, the 

 organism is also met with in some cases of spreading oedema with 

 emphysema as a leading feature. 



When tested experimentally the bacillus by itself is found to have 

 little pathogenic action. Injection of pure cultures in rabbits and 

 guinea-pigs may be followed by little result, but sometimes in the latter 

 animals "gaseous phlegmon" is produced, without suppuration unless 

 other organisms are present. If a small quantity of culture be injected 

 intravenously, e.g. in a rabbit, and then the animal be killed, bubbles 

 of gas are rapidly produced in the blood and organs, the picture corre- 

 sponding with that in the human cases. 



