I/O BACTERIOLOGY. 



inflammations of the joints and serous mem- 

 branes. 



If the tissues have become altered by other 

 diseases, such as tuberculosis or scarlet fever, 

 staphylococci or streptococci may insinuate 

 themselves secondarily and produce secondary 

 diseases or mixed infections ; thus after scarlet 

 fever there are often found diphtheritic incrus- 

 tations accompanied by the presence of strep- 

 tococci upon the mucous membrane. The 

 destruction of lung tissue that takes place in 

 tuberculosis is brought about by the suppura- 

 tion induced by staphylococci and streptococci. 

 Koch and Gaffky also found in one such case 

 Micrococcus tetragenus, a coccus grouped tab- 

 let-form in blocks of four and surrounded with 

 a capsule ; it is perhaps a phase in the life- 

 cycle of a sarcina, and should therefore more 

 correctly be called Merista or Sarcina septica. 

 It stains by Gram's method. Its growth upon 

 our ordinary culture media presents no strik- 

 ing peculiarity. It does not liquefy gelatin. 

 On inoculation, white mice and guinea-pigs 

 succumb with a sort of septicaemia, while gray 

 mice and field mice appear to be immune. 



Pneumonia. Pasteur first cultivated from 

 ordinary sputum, and Talamon from pneumoni- 

 tic sputum, a septic bacterium which A. Frankel 

 proved to be the cause of true fibrous pneu- 



