PRODUCERS OF ABSCESSES, CELLULITIS AXD SEPTICAEMIA 335 



be regarded as nearly, if not quite, a constant inhabitant of the epider- 

 mis. It is now clear \\liy I have proposed to call it the staphylococcus 

 epidermidis albus. It possesses such feeble pyogenic capacity, as is 

 shown by its behavior in wounds, as well as by experiments on rabbits, 

 that the designation staphylococcus pyogenes albus does not seem 

 appropriate. Still, I am not inclined to insist too much upon this 

 point, as very probably this coccus which has hitherto been unques- 

 tionably identified by others with the ordinary staphylococcus pyogenes 

 albus of Rosenbach is an attenuated or modified form of the latter 

 organism, although, as already mentioned, it presents some points of 

 difference from the classical description of the white pyogenic coccus." 

 According to Welch, this coccus differs from the staphylococcus 

 albus in the fact that it liquefies gelatin more slowly, does not so quickly 

 cause coagulation in milk, and is far less virulent 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 inter- 

 fere 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 and other Staphylococci. 



Isolated by Passet (1885) from the pus of acute abscesses, in which 

 it is occasionally found in association with other pyogenic cocci. It 

 is distinguished from the other species only by the formation of a lemon- 

 yellow pigment. 



Many other varieties of staphylococci have been occasionally met 

 with which differ in some respects from the typical varieties. This differ- 

 ence may be in the fact that they liquefy gelatin more slowly or not at all, 

 or in pigment formation, or in agglutination, or in still other respects. 

 None of these varieties are of great importance. 



The Micrococcus Tetragenus. 



This organism was discovered by Gaffky (1881). It is not infre- 

 quently present in the saliva of healthy individuals and in the sputum 

 of consumptive patients. In sputum it is sometimes an evidence of 

 mouth contamination rather than lung infection. It has repeatedly 

 been observed in the walls of cavities in pulmonary tuberculosis asso- 

 ciated 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 abscesses. Its presence 

 has also been noted in the pus of empyema following pneumonia. 



Morphology. Micrococci having a diameter of about I/*, which 

 divide in two directions, forming tetrads, and bound together by a tran^- 

 parent, gelatinous substance, enclosing the cell like a capsule. In 

 cultures the cocci are seen in various stages of division as large, round, 



