472 BACTERIOLOGY. 



quickly cause coagulation in milk, and is far less viru- 

 lent when injected into the circulation of rabbits. It 

 has been shown by the experiments of Bossowski and 

 of Welch that this micro-organism is very frequently 

 present in aseptic wounds, and that usually it does 

 not materially interfere with the healing of wounds, 

 although sometimes it appears to cause suppuration 

 along the drainage-tube, and it is the common cause 

 of " stitch abscess." 



Staphylococcus Pyogenes Citreus. 



Isolated by Passet (1885) from the pus of acute 

 abscesses, in which it is occasionally found (about 10 

 per cent, of the cases examined) in association with 

 other pyogenic cocci. It is morphologically identical 

 with the Staphylococcus aureus and albus, being distin- 

 guished from the other species only by the formation of 

 a lemon-yellow pigment instead of a golden-yellow, as 

 in the aureus, and a white or colorless deposit, as in the 

 albus. 



THE MICROCOCCUS TETRAGENUS. 



This organism was discovered by Gaffky (1881). It 

 is not infrequently present in the saliva of healthy in- 

 dividuals and in the sputum of consumptive patients. 

 In sputum it is sometimes an evidence of mouth con- 

 tamination rather than lung infection. It has repeatedly 

 been observed in the walls of cavities in pulmonary 

 tuberculosis associated with other pathogenic bacteria, 

 which, though playing no part in the etiology of the 

 original disease, contribute, doubtless, to the progressive 

 destruction of the lung. Its pyogenic character is shown 

 by its occasional occurrence in the pus of acute ab- 



