SUPPURATION, PY^MIA, SEPTICAEMIA, ERYSIPELAS. 187 



\vitli Streptococcus pyogenes. have been found in cattle plague, foot 

 and mouth disease, strangles, contagious mammitis in cows, and 

 progressive tissue necrosis in mice, and they will be referred to fully 



in subsequent chapters. 



EXAMINATION AND CULTIVATION OF STREPTOCOCCI. 

 Cover-glass preparations can be stained with the watery solutions 

 of the aniline dyes. In some cases very beautiful preparations can 

 be obtained by using Neelsen's solution, and removing excess of 



b. c. . d. 



FIG. 89. STREPTOCOCCUS PYOGENES HOMINIS. Pure-cultures on nutrient 



gelatine. 



, Sub-culture from agar. 

 c, Sub-culture from milk. 



b, Sub-culture from broth. 

 d, Sub-culture from milk. 



stain by rinsing in alcohol. To examine pus, milk, or broth, take 

 nn ordinary platinum needle bent at the extremity into a booklet. 

 Dip it into the liquid to be examined, and spread it on a cover- 

 idass into as thin a film as possible; the preparation is treated 

 in the ordinary way, that is 'to say, the film is allowed to dry, 

 and the cover is taken up with forceps, and passed three tinio 

 through the flame with its prepared side uppermost. 



Gram's Method with Eosin. In this way the streptococci art- 

 stained blue, and stand out in marked contrast to the rest of the 

 preparation. Use freshly prepared solution. Float tbe cover-glasses 



