178 INFECTIVE DISEASES. 



association with suppuration, pyaemia, puerperal fever, and acute 

 osteomyelitis. 



Staphylococcus pyogenes albus (Rosenbacli). — Cocci micro- 

 scopically indistinguishable from the above. In cultivations also 

 they resemble Staphylococcus pyogenes aureus, but the growth 

 consists of opaque white masses. They, as a rule, liquefy nutrient 

 gelatine very rapidly, and subside to the bottom as a white sediment ; 

 more rarely they liquefy very slowly ; and a variety has also been 

 described which does not produce any liquefaction. They are similar 

 to the above-mentioned in their pathogenic action. Pure-cultivations 

 of the organism were obtained from a case of acute suppuration 

 of the knee-joint. 



Staphylococcus pyogenes citreus (Passet). — Cocci singly, in 

 pairs, very short chains, and irregular masses. If cultivated on 

 nutrient gelatine or nutrient agar-agar, a sulphur or lemon-yellow 

 growth develops. When inoculated under the skin of mice, guinea- 

 pigs, or rabbits, an abscess forms after a few days, from which a 

 fresh cultivation of the micro-organism can be obtained. 



Staphylococcus cereus albus (Passet). — Cocci, morphologic- 

 allj' similar to the above, but distinguished by forming on nutrient 

 gelatine a white, slightly shining layer, like drops of stearine or wax, 

 with somewhat thickened, irregular edges. In the depth of gelatine 

 they form a greyish- white, granular thread. In plate-cultiva- 

 tions, on the first day, white points are observed, which spread 

 themselves out on the surface to spots of 1 to 2 mm. When culti- 

 vated on blood serum a greyish-white, slightly shining streak 

 develops, and on potatoes the cocci form a layer which is similarly 

 coloured. 



Staphylococcus cereus flavus (Passet). — Cocci which produce 

 in nutrient jelly a growth which, at first white, becomes lemon- 

 yellow, somewhat darker in colour than Staphylococcus pyogenes 

 citreus. Microscopically Staphylococcus cereus flavus corresponds 

 with Staphylococcus cereus albus. Inoculation experiments with 

 both kinds give negative results. 



Streptococcus pyogenes (Rosenbach).- — Cocci occurring singly, 

 in masses, and in chains. The individual cocci are small spherical 

 cells, with a special tendency after fission for the resulting elements 

 to remain attached to each other, forming chains or rosaries. In 

 cultures on solid media they often occur in the form of staphylococci, 

 but in liquid cultures there may be a few, three or more elements, 

 linked together ; or a great number, forming long chains which may 

 be straight, serpentine, or twisted. 



