LESS COMMON PYOGENIC ORGANISMS 281 



links ; 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 ajjpear flattened on the sides adjacent to one another. 

 The chains are sometimes short, consisting of four to six 

 cells ; or, again, they may be much longer, and extend from 

 a half to two-thirds across the field of the microscope. 



Under artificial conditions it sometimes grows well, 

 and can be cultivated through many generations, while 

 at other times it rapidly loses its vitality. When isolated 

 from the diseased area upon artificial media it seems to 

 retain its vitality for a longer period if replanted upon 

 fresh media every day or two for a time ; but if the 

 first generation is transplanted and is allowed to re- 

 main upon the original medium, it is not uncommon 

 to find the organism incapable of further cultivation 

 after a week or ten days. 



Under no conditions is the growth of this organism 

 very luxuriant. 



On gelatin plates its colonies appear after forty-eight 

 to seventy-two hours as very small, flat, round points of 

 a bluish-white or opalescent appearance. They do not 

 cause liquefaction of the gelatin, and in size they rarely 

 exceed 0.6-0.8 mm. in diameter. Under low magnify- 

 ing power they have a brownish or yellowish tinge by 

 transmitted light, and are finely granular. As the col- 

 onies become older their regular border may become 

 slightly irregular or notched. 



In stab-cultures in gelatin they grow along the entire 

 needle-track as a finely granular line, the granules rep- 

 resenting minute colonies of the organism. On the 

 surface the growth does not usually extend beyond the 

 point of puncture. 



