356 APPLICATION OF METHODS OF BACTERIOLOGY 



tures it will be found on microscopic examination to present 

 an arrangement somewhat like a chain of beads. (Fig. 68.) 



Its peculiarities should be as follows: 



Upon microscopic examination a micrococcus should be 

 found, but differing in its arrangement from those just 

 described. The single cells are not scattered irregularly or 

 arranged in clumps similar to bunches "of grapes, but are 

 joined together in chains like strands of beads. These 

 strands are sometimes regular in the arrangement and size 

 of the individual cells composing them, but more commonly 

 certain irregular groups may be seen in them, appearing 



FIG. 68 



/,/ 



Streptococcus pyogenes. 



as if two or three cells had fused together to form a link 

 in the chain, so to speak, that is somewhat longer than the 

 others; again, portions of the chain may be thinner than 

 the rest, or it may appear broken or ragged. Commonly 

 the individuals comprising this chain of cocci are not round, 

 but appear flattened on the sides. The chains are some- 

 times short, consisting of but four to six cells; or, again, they 

 may be much longer, and extend from a half to two-thirds 

 the way across the field of the microscope. 



Under artificial conditions this organism sometimes grows 

 well, and can be cultivated through many generations, while 



