402 BACTERIA IN CROUPOUS PNEUMONIA. 



In a case of tonsillitis resulting in the formation of an abscess 

 Gabbi (1889) obtained the same coccus in pure cultures. 



In otitis media this micrococcus has been found in a consider- 

 able number of cases in the pus obtained by paracentesis of the 

 tympanic membrane, and quite frequently in pure cultures by Zau- 

 fal (1889) in six cases; Levy and Schrader (1889) in three out of ten 

 cases in which paracentesis was performed; by Netter (1889) in five 

 out of eighteen cases occurring in children. 



Monti (1889) and Belfanti (1889) report cases of arthritis of the 

 wrist joint, occurring as a complication of pneumonia, in which this 

 micrococcus was obtained in pure cultures. Ortmann and Samter 

 (1889), in a case of purulent inflammation of the shoulder joint fol- 

 lowing pneumonia and pleurisy, obtained the "diplococcus pneu- 

 monise " in pure cultures. 



Morphology. Spherical or oval cocci, usually united in pairs, or 

 in chains consisting of three or four elements. Longer chains, con- 

 taining ten or more elements, are frequently formed, especially in 

 cultures upon the surface of nutrient agar, and in liquid media; it 

 may therefore be regarded as a streptococcus. As observed in the 

 blood of inoculated animals it is usually in pairs consisting of oval 

 or lance-oval elements, which are surrounded by a transparent cap- 

 sule. Owing to the elongated form of the cocci when in active 

 growth, it has been regarded by some authors as a bacillus; but in 

 cultures in liquid media, when development by binary division has 

 ceased, the cells are spherical, or nearly so, and in cultures on the 

 surface of nutrient agar the individual cells more nearly approach a 

 spherical form than in the blood of an inoculated animal. The " lan- 

 ceolate " form was first referred to by Tala- 

 mon, who described it as having the form of 

 a grain of wheat, or even still more elongated 

 like a grain of barley, as seen in the fibrin- 

 ous exudate of croupous pneumonia. The 

 transparent material surrounding the cells- 

 so-called capsule is best seen in stained 

 preparations from the fibrinous exudate of 

 FIG. 93.-Micrococcus pneu- croupous pneumonia or from the blood of an 



monise crouposae, showing cap- 

 sule, attached to pus cells from inoculated animal. It appears as an un- 



st ined marginal band surrounding the ellip- 

 tical cells, and varies greatly as to its extent 

 in different preparations. This capsule probably consists of a sub- 

 stance resembling mucin, and, being soluble in water, its extent de- 

 pends partly upon the methods employed in preparing specimens for 

 microscopical examination. It is occasionally seen in stained prep- 

 arations from the surface of cultures on blood serum ; and in drop 



