SUMMARY 251 



develop, or develops very feebly, on ordinary media. Not 

 pathogenic for animals. Occurs most abundantly in pus 

 cells in gonorrheal infections. Exhibits group serum 

 reactions with D. Weichselbaumii. 



Species 3. D. Weichselbaumii (Weichselbaum) Trevisan. 



A coccus occurring commonly in pairs of flattened coffee- 

 bean shaped cells. Decolorizes by Gram. Develops 

 feebly on ordinary media. Slightly pathogenic for animals. 

 Occurs in cerebro-spinal exudate in epidemic meningitis. 

 Exhibits group serum reactions with D. gonorrhcecz. 



Species 4. D. catarrhalis Frosch and Kolle. 



A coccus occurring commonly in pairs of flattened coffee- 

 bean shaped cells. Decolorizes by Gram. Grows fairly 

 well on artificial media, forming grayish-white colonies 

 with a denser center. Growth on streak dry and friable. 

 Virulence slight. Occurs in normal throat. 



Species 5. D. involutus (Kurth) Winslow. 



A coccus occurring commonly in chains, the elements of 

 which are grouped in pairs. In the body, and on media, 

 the chains are surrounded by a well-marked capsule. 

 Growth on media fairly abundant, moist and slimy. 

 Ferments monosaccharides, disaccharides, and inulin. 

 Lacks hemolytic power. Shows group serum reactions 

 with D. pneumonia. Occurs on the epithelial surfaces, 

 and in the tissues, of man and the higher animals. 



