266 PATHOGENIC BACTERIA. 



the reader must be referred to the chapter upon Pneumo- 

 nia, where it is considered in full. 



The Bacillus coli communis, which is always present in 

 the intestine, seems at times to enter the blood- or lymph- 

 channels and stimulate suppuration, and numerous cases 

 are on record showing this. The points most frequently 

 attacked seem to be the bile-ducts and the vermiform ap- 

 pendix, though the significance of the organism in appen- 

 dicitis has no doubt been overrated. It has also been found 

 in the kidney in scarlatinal nephritis, and is thought to 

 be the exciting cause of some cases. It was originally 

 described by Passet as the Bacillus pyogenes fcetidus. 

 For a more particular study of this organism the reader 

 is referred to the chapter devoted to its consideration. 



The Bacillus typhosus is probably less frequently a cause 

 of suppuration than either of the others, yet it seems to 

 be the occasional cause of the purulent sequelae of typhoid 

 fever. A case has recently been reported by Flexner in 

 which metastatic abscesses were found to be caused by it. 



The Micrococcus tetragenus has also been found in the 

 pus of acute abscesses: it is quite common in the cavities 

 of pulmonary tuberculosis, and may aid in the destructive 

 processes involved in the general phthisical infection. 



Micrococcus Gonorrhoeae. 



All authorities now accept the "gonococcus" to be 

 the cause of gonorrhea. It was first observed in the 

 urethral and conjunctival secretions of gonorrhea and 

 purulent ophthalmia by Neisser in 1879. The organisms 

 are of hemispherical shape, arranged in pairs, so that 

 the inner surfaces are separated from each other by a 

 narrow interval. Sometimes, instead of pairs of cocci, 

 fours are seen, the group no doubt resulting from the 

 division of a pair. 



The described hemispherical shape is not exactly cor- 

 rect, for a good lens generally shows the approximated 

 surfaces to be somewhat concave rather than flat. The 



