122 BACTERIOLOGY. 



Sarcina Reitenbachii, Caspary. Cocci about 

 i '5 to 2 -5 //, in diam., at the time of division 

 lengthened to 4 //,. Mostly united together from 

 4 to 8 in number; occasionally 1 6 or more. Colour- 

 less cell-wall, lined with rose-red layer of plasma. 

 Found on rotting water plants. 



Sarcina hyalina, Kiitzing. Cocci round, 2*5 

 p, in diam., almost colourless. United in families 

 of 4 to 24 cells, reaching 15 //, in diam. In marshes. 



Genus IV. Micrococcus. 



Micrococcus pyogenes aureus (Staphylococcus 



pyogenes aureus Rosen bach. Yellow coccus in pus. 

 Coccus of acute infectious osteomyelitis). Cocci singly, 

 or aggregated in masses. Cultivated on nutrient 

 agar-agar an orange-yellow culture develops, look- 

 ing like a streak made with oil paint * (Plate VIII., 

 Fig. 2). Cultivated in a test-tube of nutrient 

 gelatine, the gelatine is rapidly liquefied, and the 

 growth subsides as an orange-yellow sediment. 

 On potatoes and blood serum a similar orange- 

 yellow culture grows luxuriantly. 



The micro-organisms injected into the pleura or 

 knee of a rabbit produce, as a rule, a fatal result 

 on the following day, but if it survives longer, it 

 eventually dies of severe phlegmon. If injected 

 into the knee of a dog, suppuration occurs, 

 followed by disintegration of the joint. The cocci 

 do not cause any septic odour in pus, nor does 



* Rosenbach, ibid. 



