PLATE i. 

 Streptococcus pyogenes. Rosenbach. 



I. Agar streak culture, ten days at 37. 

 II. Gelatin stab culture, six days at 22. So vigorous 

 a growth does not often occur. 



III. Agar stab culture, six days at 37. Stab canal. 



IV. Agar stab culture, six days at 37. Surface growth. 

 V. Gelatin plate, six days at 22. 



VI. Gelatin plate, six days at 22. X 70. Somewhat 

 abnormal form with irregular borders. The larger colonies 

 are superficial; the smaller, deep. 



VII. Gelatin plate, six days at 22. X 70. Common 

 form. The upper, superficial; the lower, deep. 



VIII. Agar plate, eight days at 37. X 50. Larger colony 

 superficial ; smaller colonies, deep. 



IX. Microscopic preparation from a two days' bouillon 

 culture at 37. X 700. The individual cocci are usually 

 more regularly round. 



X. Microscopic preparation from a two days' agar 

 culture. Shorter chains. X 1000. 



XI. Microscopic preparation, designated Streptococcus 

 conglomeratus. Smear -preparation from the blood of the 

 spleen from a case of scarlatina. Copied from Kurth 

 (Kaiserl. Gesundheitsamt., Bd. vn, cfr. xv, 6 and 8). 



XII. Chains of streptococci, before and during division. 

 Highly magnified. 



7 



XII. 



