STAPHYLOCOCCUS PYOGENES AUREUS 199 



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 tenuis. Other organisms are met with in suppuration, 

 such as staphylococcus pyogenes citreus, staphylococcus cereus 

 albus, staphylococcus cereus flavus, micrococcus tetragenus, pneu- 

 mococcus, pneumobacillus (Priedlander), meningococcus, bacillus 

 pyogenes fcetidus (Passet), bacillus coli communis, bacillus lactis 

 aerogenes, bacillus pyocyaneus, bacillus proteus, and others. 

 Various anaerobic bacteria are also concerned in the production 

 of an inflammation which is often associated with oedema, 

 haemorrhage, or necrosis {vide Chapter XVII.). 



In secondary inflammations and suppurations following acute 

 specific diseases, the corresponding organisms have been found 

 in some cases, such as gonococcus, typhoid bacillus, para- 

 typhoid bacilli, influenza bacillus, etc. Suppuration is also 

 produced by the actinomyces and by 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. 44). 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. 45). In gelatin plates colonies may 

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

 hours, as little balls somewhat granular on the surface and of 

 brownish colour. On the second day they are visible to the 



