208 INFLAMMATION AND SUPPURATION 



many have 4 been proved to be causally related, whilst of some 

 others the exact action has not yet been fully determined. 



Ogston, who was one of the first to study this question (in 

 1881), found that the organisms most frequently present were 

 micrococci, of which some were arranged irregularly in clusters 

 (staphylococci), whilst others formed chains (streptococci). He 

 found that the former were more common in circumscribed 

 acute abscesses, the latter in spreading suppurative conditions. 

 Rosenbach shortly afterwards (1884), by means of cultures, 

 differentiated several varieties of micrococci, to which he gave 

 the following special names : staphylococcus pyogenes aureus, 

 staphylococcus pyogenes albus, streptococcus pyogenes, micrococcus 

 pyogenes tennis. Other organisms are met with in suppuration, 

 such as staphylococcus pyogenes citreus, staphylococcus cereus 

 albus, staphylococcus cereus ftavus, pneumococcus, pneumobacillus, 

 (Friedlander), bacillus pyogenes foetidus (Passet), bacillus coli 

 communis, bacillus lactis aerogenes, bacillus aerogenes encapsul- 

 atus, bacillus pyocyaneus, micrococcus tetragenus, pneumococcus, 

 pneumobacillus, diplococcus intracellularis meningitidis, and 

 others. Various anaerobic bacteria are also concerned in the 

 production of inflammation, which is often associated with 

 oedema, haemorrhage, or necrosis (vide Chapter XVII.). 



In secondary inflammations and suppurations following acute 

 diseases, the corresponding organisms have been found in some 

 cases, such as gonococcus, typhoid bacillus, influenza bacillus, 

 etc. Suppuration is also produced by the actinomyces and the 

 glanders bacillus, and sometimes chronic tubercular lesions have 

 a suppurative character. 



Staphylococcus Pyogenes Aureus. Microscopical Characters. 

 This organism is a spherical coccus about '9 /x, in diameter, 

 which grows irregularly in clusters or masses (Fig. 49). It 

 stains readily with all the basic aniline dyes, and retains the 

 colour in Gram's method (Plate I., Fig. 1). 



Cultivation. It grows readily in all the ordinary media at 

 the room temperature, though much more rapidly at the 

 temperature of the body. In stab cultures in peptone gelatin 

 a streak of growth is visible on the day after inoculation, and 

 on the second or third day liquefaction commences at the top. 

 As liquefaction proceeds, the growth falls to the bottom as a 

 flocculent deposit, which soon assumes a bright yellow colour, 

 while a yellowish film may form on the surface, the fluid portion 

 still remaining turbid. Ultimately liquefaction extends out to 

 the wall of the tube (Fig. 50). In gelatin plates colonies may 

 be seen with the low power of the microscope in twenty-four 



