THE BIOLOGY OF MICROBES, ETC. 119 



Micrococcus subflavus. The cells are 0'8 //, in 

 diameter, and occur singly, in pairs, in tetrads, and 

 zooglcea groups. On gelatine they form white dots, 

 which ultimately become yellow and confluent. This 

 microbe was originally found in vaginal secretions 

 and lochial discharges. 



Micrococcus radiatus. The cells are 0'8 p in 

 diameter, and occur singly and in short chains. They 

 form ' whitish colonies with a yellowish-green sheen.' 

 The colonies liquefy the gelatine and sink down in 

 it ; there developing, in the course of a day or two, 

 a circlet of rays. 



Micrococcus pyogenes citreus. The cells occur 

 singly, in chains, and masses. They grow on nutrient 

 agar-agar and gelatine, giving rise to a lemon-yellow 

 pigment. They are obtained from pus. 



Micrococcus pyogenes. The cells are 1 p in diame- 

 ter, and occur in chains or diplococci. They form 

 small colonies which grow slowly ; on plate-cultiva- 

 tions they are first white, then pale yellow, and 

 finally become brown. They (the colonies) have no 

 tendency to run together in either plate, stroke, 

 or puncture cultivations, except on agar-agar or 

 blood serum where the mass is thicker in the 

 centre. They do not grow on potatoes ; and do 

 not liquefy any medium. They occur in the pus 

 of acute abscesses. 



Micrococcus pyogenes aureus. This coccus occurs 

 in osteomyelitis. It grows on boiled potatoes, 

 nutrient gelatine, agar-agar, and blood serum, giving 

 rise to orange cultures. This microbe liquefies 

 gelatine, and the colonies remain limited to the 



