INDIVIDUAL FEATURES OF PYOGEXIC BACTERIA. Ill 



the Staphylocoecus aureus rapidly causes a fatal septicaemia. 

 Rabbits and guinea-pigs die, as a rule, in twenty-four to 

 forty-eight hours after inoculation, and the organisms may be 

 found generally disseminated in the blood-capillaries of the 

 organs, and are also found in the blood taken from the heart. 



Inoculations into the peritoneal cavity cause a purulent 

 peritonitis of a virulent character, generally ending in death 

 of the animal. Injected under the skin, this organism pro- 

 duces localized abscesses. 



The larger number of surgical infections are due to Staphy- 

 lococcus pyogvnes aureus. 



II. Staphylococcus Pyogenes Albus. 



The Staphylococcus pyogenes albus, like its companion the 

 aureus, exists as a saprophyte : a. on the surface of the skin 

 in man, and b. in association with the aureus in abscesses 

 and superficial phlegmons. 



Although clinicians are in the habit of considering it as an 

 achromogenic variety of the preceding, it is, however, some- 

 what less pathogenic. Its morphological characters are the 

 same as those of the aureus, with the exception that it does 

 not form pigment and its colonies are of a milk-white color. 



III. Staphylococcus Citreus. 



The Staphylococcus pyogenes citreus is of identical mor- 

 phology with the two preceding varieties, with the exceptions 

 that its growth is of a lemon-yellow color and that it liquefies 

 gelatin more slowly. It is found in association with the Sta- 

 phylococcus aureus and albus in pus of acute abscesses, espe- 

 cially in the liver. 



IV. Streptococcus Pyogenes. 



The Streptococcus pyogenes is found : a. in the lymphatics 

 of the skin in patients suffering from erysipelas, b. in pus, 

 c. in the false membranes in cases of diphtheria, d. in surgi- 

 cal and e. as a frequent causative agent of puerperal septi- 



