PRODUCERS OF ABSCESS, CELLULITIS, ETC. 473 



scesses. Its presence has also been noted in the pus of 

 empyema following pneumonia. 



Morphology. Micrococci having a diameter of about 

 Ijut, which divide in two directions, forming tetrads, 

 and bound together by a transparent, gelatinous sub- 

 stance, enclosing the cell like a capsule. In cultures 

 the cocci are seen in various stages of division as large, 

 round, undivided cells, in pairs of oval elements, and 

 in groups of three and four (Fig. 60). When the divis- 



PlG. 60. 



Micrococcus tetragenus. X 1000 diameters. 



ion is complete they remind one of sarcinae in appear- 

 ance, except that they do not divide in three directions 

 and are not built up like diminutive cotton bales. 



This micrococcus stains readily with the ordinary ani- 

 line dyes; the transparent gelatinous envelope is only 

 feebly stained. It is not decolorized by Gram's method. 



Biological Characters. The growth of this micro- 

 coccus is slow under all conditions. It grows both in 

 the presence and absence of oxygen; it grows best from 

 35 to 38 C., but may be cultivated also at the ordi- 

 nary room-temperature about 20 C. 



