MICROCOCCI PATHOGENIC IN MAN. 189 



toms described above. As, however, the experiments were 

 made only with fluid media there is no absolute certainty 

 that in these experiments impurities in the cultivations did 

 not lead to mistakes. 



Micrococcus pyogenes tennis. 



Found by Kosenbach in a few instances (in 10 per cent, 

 of the cases examined) as the only micro-organism pre- 

 sent in the pus of unopened abscesses. Irregular cocci, 

 somewhat larger than staphylococci, showing in con- 

 trast to the latter, but little tendency to the formation 

 of masses. Two dark poles with clear intermediate 

 substance are frequently observed in the micrococci ; the 

 cultivations on agar have the appearance of thin deposits 

 spreading out from the line of inoculation, almost as 

 clear as glass ; in puncture cultivations a somewhat 

 thick and slightly opaque layer is formed. No experi- 

 ments on animals have as yet been made. 



Streptococcus pyogenes. 



First recognised by Ogston from its microscopical Pyogenic 

 appearance ; cultivated from pus by Kosenbach, then by 8 

 Krause and Passet. Spherical cocci, about 1 //- in dia- 

 meter, larger than the staphylococci. Eetain the stain 

 in Gram's method. What is very characteristic, and the 

 origin of the name of this species, is the tendency of the 

 cocci to divide continuously in the same direction and to 

 form chains of 4, 5, or even 10, or 

 more cocci; these chains are fre- 

 quently united in delicate loops to 

 form larger heaps. Besides the chain 

 form, the fungus often appears as a 

 diplococcus. At times one or other 

 cell in a chain is larger than the rest; 

 it is not certain whether this indi- 

 cates the formation of arthrospores. -p[g. 44. Pus contain- 

 The streptococcus grows on gelatine in s streptococcus Growth on 



i , . ,-, /. ?i x yo - gelatine 



plates in the form of very small punc- plates. 



tiform colonies which spread out on the surface as very 



