Acute Croupous Pneumonia. Pneumonitis in the Horse. 217 



four, and under given circumstances surrounded by a transparent 

 gelatinous capsule. It is aerobic, nonmotile, does not liquefy 

 gelatine, nor sporulate, and in gelatine stick cultures has a nail- 

 like growth. This was found by Friendlander, Frobenius, 

 Weichselbaum and Wolf in the pulmonary alveoli in a small pro- 

 portion of cases of croupous pneumonia in man. The cultures, 

 injected into the lungs of animals, killed one dog (out of five), six 

 Guinea pigs (out of eleven), and thirty-two mice (all the in- 

 jected). I^esions were intense congestion of the lungs, seropuru- 

 lent pleural effusion, and enlarged spleen, while the bacillus 

 swarmed in the blood and exudate. 



Micrococcus Pneumonia Crodpos^. First found by Stern- 

 berg in his own saliva in health, and by Pasteur in the saliva of a 

 rabid child. Afterward found in the great majority of lungs 

 affected with croupous pneumonia in man, by Talamon, Salvioli, 

 Sternberg, Frankel, Weichselbaum, Netter, Gamalei, etc. Later 

 it was found in meningitis, in ulcerative endocarditis, in ar- 

 thritis, in otitis media, and in acute abscess in man. 



It is a spherical or oval coccus, arranged in pairs, in fours, or ex- 

 ceptionally in eights or tens. I,anceolate forms are the rule in 

 the blood of animals, and circular in artificial cultures. It stains 

 readily in aniline colors and by Gram's method, grows inordinary 

 culture media, at 37° C. in the absence of free acid, and in 

 gelatine stick cultures as small, white colonies along the line of 

 culture, without liquefying the gelatine. It dies in ten minutes 

 at 52" C. (Sternberg). Its virulence lessens in artificial cul- 

 tures, but is restored by passing through the body of a suscepti- 

 ble animal. 



Injection into the lungs or trachea of rabbits, mice, sheep and, 

 less certainly, Guinea pigs, produced distinct fibrinous pneumonia 

 filled with the microbe. In dogs, subcutaneously, it caused ab- 

 scess, but in the lungs an acute fibrinous pneumonia which only 

 exceptionally proved fatal , recovery usually taking place in ten to 

 fifteen days. 



Klemperer induced immunity, sometimes lasting six months, 

 by intravenous injection of filtered cultures. 



DiPLOCOCCus PNEUMONije EQUINA. Finst found by Schiitz in 

 the lungs of pneumonic horses in 1887. It is an oval coccus ar- 

 ranged usually in pairs or in threes or fours, and surrounded by 



