PATHOGENIC BACTERIA. 115 



In 1886 A. Frankel and Weichselbaum proved that this 

 microbe was not constant, in fact was rare. 



A. Frankel obtained in the majority of cases of pneumonia a 

 microbe that he had described in 1884 under the name of 

 sputum-septicaemia micrococcus. 



Weichselbaum now called it " Diplococcus Pneumonia," and 

 believed it to be the real cause of pneumonia. It has been found 

 in many other serous inflammations, and also in the mouth of 

 healthy persons. 



Streptococcus pyogenes and staphylococcus pyogenes aureus have 

 beefc found in some cases. 



FIG. 62. 



Pneumo-bacillus of Friedlander, with capsule. 



Pneumo-bacillus (Pneumococcus). (Friedlander.) 



Origin. In the lung of a croupous-pneumonia person, by 

 Friedlander, in 1882. 



Form. Small, almost oval-shaped rods, nearly as wide as 

 they are long ; often in pairs, they were at first believed to be 

 cocci. In bouillon cultures the rod-form becomes more visible. 

 In tissues each bacillus is surrounded by a faint capsule ; but 

 not around those developed in artificial cultures. Spores have 

 not been found. 



Properties. They are immobile ; do not liquefy gelatine. A 

 gas is produced in gelatine cultures. 



Growth. Grows rapidly on all media at ordinary temperature : 

 is facultative aerobic. 



Colonies. On gelatine plates. Small white round colonies, 

 reaching the surface in the course of three or four days ; appear- 

 ing then as little buttons, with a porcelain-like shimmer, the 

 edges smooth. 



Stab Culture. A growth along the needle-track, but on the 

 surface a button-like projection, which gives to the growth the 



