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- 
