vni] ■ MICROCOCCI 149 



the seat of inoculation, and gradually extending towards the 

 tip of the ear; in three to four days the whole, ear is red, 

 swollen, hot, and pendulous ; later on, when the process retro- 

 grades, the epidermis is raised in blisters and peels just as 

 in erysipelas of man. The process is sometimes so severe that 

 the ear sloughs, or general septicaemic infection occurs ; 

 occasionally not only the ear but also the skin of the neck 



Fig. 34. — Film Specimen of'Streptococcus ScARLATiN.e from a Fluid 

 Culture, x iooo. 



becomes involved. Sometimes on subcutaneous injection 

 of the culture at the root of the ear an acute septicaemic 

 infection is at once produced, the anima,! dying in twenty- 

 four to thirty-six hours, and the blood containing the strepto- 

 cocci in large numbers. Cultivations with a droplet of the 

 serum from the erysipelatous ear always yield numerous 

 colonies of the streptococcus. 



After repeated subcultures on gelatine or Agar the virulence 



