PNEUMOCOCCUS OF FRIEDLANDER 379 



in man is in a majority of cases caused by the Diplococcus lanceolatus, 

 it may also be caused by the Diplococcus or Diplobacillus of Fried- 

 lander, the Micrococcus catarrhalis, and the bacilli of influenza, 

 glanders, diphtheria, plague, and others. 



Whether every case of contagious pneumonia of horses is always 

 due to equine influenza, i. e., to the Bacillus bipolaris equisepticus, 1 

 or whether certain non-contagious pneumonias in horses are due to 

 other bacteria is a question on which opinion is divided. It, however, 

 appears established that the diplococcus pneumonise or lanceolatus 

 is also the cause of pneumonia in the horse, and that in old animals, 

 or after long-continued debilitating diseases it frequently leads to a 

 fatal issue. 



MIGROGOCGUS GATARRHALIS. 



This was first seen by Seiffert and obtained in pure cultures by 

 Kirchner and by Pfeiffer. It is a biscuit-shaped coccus, generally 

 occurring in pairs or tetrads. It stains well with the ordinary watery 

 anilin stains, but is Gram negative. It is not motile, and does not 

 form spores. It is found in the normal mucous membranes, and also 

 in diseases of the upper or lower respiratory tract in man. It grows 

 on the ordinary laboratory culture media between 20 and 40 C., best 

 at blood temperature. It forms grayish-white or yellowish-white 

 colonies with irregular margins, as if artificially cut out. Gelatin is 

 not liquefied; bouillon becomes cloudy, a pellicle often forming on the 

 surface. Milk is not coagulated. The organism varies considerably 

 in virulency. It sometimes kills guinea-pigs, rabbits, and mice in 

 intraperitoneal inoculations. 



PNEUMOCOCCUS OF FRIEDLANDER. 



This organism should more properly be called the Pneumobacillus 

 of Friedldnder, as it is not a true coccus but a short bacillus. In 

 pathogenic exudates it is often so short that it was at first mistaken 

 for a coccus. It generally occurs in groups of two or in tetrad form 

 or in short chains, and when found in sputum or pus frequently 

 possesses a capsule. It can easily be differentiated from the Diplo- 

 coccus pneumonia of Frankel because it is Gram negative. It does 

 not form spores, is not motile, and possesses no flagella. It is aerobic. 

 It shows a nail growth in gelatin stick culture, i. e., it forms a heavy 

 growth on the surface from which a streak of culture extends along 

 the stab. It does not liquefy the gelatin, but imparts to it a distinct 

 brownish tint distinguishing it from the very similar growth which 

 the Bacillus aerogenes forms on this medium. The growth on 



1 Described in the chapter on the Hemorrhagic Septicemia Bacilli. 



