SUPPURATION, PY^MIA, SEPTICAEMIA, ERYSIPELAS. 181 



According to Fliigge and others, after subcutaneous inoculation 

 of mice with a small quantity of a cultivation, there is no result in 

 80 per cent, of the animals experimented upon. Sometimes there 

 is limited pus formation at the seat of inoculation, sometimes the 

 animals die without any very striking pathological appearances. 



They occur in abscesses, pyaemia, and septicaemia, and are often 

 found in diseases such as scarlet fever and typhoid, associated with 

 septic complications. They have been isolated from air, soil, and 

 water. 



The streptococcus found in erysipelas agrees in description, and 

 is merely a variety of Streptococcus pyogenes. It has been definitely 

 established by the researches of Frankel and Freudenberg, and later 

 by those of the author, Raskin, Prudden, and Bayard Holmes, 

 that Streptococcus pyogenes is frequently found in scarlet fever and 

 diphtheria, and in other diseases associated with septic complica- 

 tions. The author has isolated Streptococcus pyogenes from acute 

 abscesses, from suppuration after surgical operations, from pyaemia, 

 from pyaemia after scarlet fever, and from purulent peritonitis. 

 Some of these cultures have been kept up for very long periods, 

 extending over some years, so that opportunities occurred for a 

 complete investigation into the life history of this micro-organism. 

 Variations in the appearances of cultures have been observed when 

 obtained from the same source. A number of cultures from pus 

 were prepared 011 gelatine and agar, made according to the usual 

 formula, but at different dates, and, therefore, varying slightly in 

 composition and quality. Sub-cultures were also started in nutrient 

 gelatine of precisely the same composition, but from primary cul- 

 tures of the same micro-organism in different media agar-agar, 

 milk, and broth. The descriptions of the streptococcus hitherto 

 published were then found to be inadequate. The different cultures 

 and sub-cultures presented striking variations in the microscopical and 

 macroscopical appearances. Some sub-cultures on gelatine, for exam- 

 ple, exhibited a finely dotted appearance, others showed every variety 

 in the size, and degree of opacity of the colonies (Fig. 89). Cultures 

 in broth also, varied in appearance, owing to slight variation in the 

 composition of the medium, to slight differences of temperature, anl 

 other conditions difficult to determine. The addition of glycerine to 

 broth materially alters the appearance of the culture. It was con- 

 clusively proved that minute differences arise from different conditions 

 of the cultivating media. The author was led to study exhaustively 

 the streptococcus of acute suppuration in bo vines. Primary cultures 

 of Streptococcus pyogenes from man, and primary cultures from 



