172 SUPPURATION- PUS COCCI. 



lar. In a gelatin stab many small colonies form along the 

 needle-track, and on the surface a little projection or button 

 is formed, the typical nail-growth. On potato the growth is 

 very luxuriant. 



Pathogenesis : The tetracoccus is pathogenic for animals but 

 not for man. It is very fatal for white mice in the labora- 

 tory. Lartigau believes that Microeoccus tetragenus may be 

 the cause of a pseudomembranous angina. He has observed 

 three cases of this kind. The tetracoccus is frequently seen 

 in specimens of tubercular sputum. Its shape is very char- 

 acteristic and cannot fail to attract attention. 



