640 Tetragenus 



abundant, especially at the temperature of the incubator. 

 It has no distinctive peculiarities. 



Pathogenesis. The introduction of tuberculous sputum 

 or of a minute quantity of a pure culture of this coccus into 

 white mice usually causes a fatal bacteremia. 



The organisms are found in small numbers in the heart's 

 blood, but are numerous in the spleen, lungs, liver, and 

 kidneys. 



House-mice and field-mice, dogs and rabbits are com- 

 paratively immune. Guinea-pigs die of general septic infec- 

 tion, though local abscesses result from subcutaneous inocu- 

 lation. 



The tetracocci, when present, probably hasten the tissue- 

 necrosis in tuberculous cavities, aid in the formation of ab- 

 scesses of the lung, and contribute to the production of the 

 hectic fever. 



An interesting contribution to the relationship of this 

 coccus to human pathology has been made by Lartigau,* 

 who succeeded in demonstrating that the tetracoccus may 

 be the cause of a pseudo -membranous angina, three cases of 

 which came under his observation. 



*"Phila. Med. Jour.," April 22, 1899. 



