CULTIVATION AND COLONIES 



66 3 



employment of nutrient' gelatine, nutrient agar-agar, and other 

 similar media on glass plates, and in test-tubes (fig. 501), so as by 



PIG. 501. Pure- cultivations of Streptococcus pyogenes : a, on the surface of 

 nutrient gelatine ; It, in the depth of nutrient gelatine ; f, on the surface of 

 nutrient agar. iCrookshank.) 



^w^a& 



& 



> w : m- ;- v" 



^^'^-^t' w 

 A- ^^-^^^^^"V,, 



iMjfet v-, ,, 

 k 



. 



' ^ m-P' 1 V *//" "iT^^^i 



W{;:-%^\^-" : -"-"> 



''|"_' r " Sf' ''_'],; 



FIG. 502. Colonies of Bacillus antli-aria, x 80 : a, after 24 hours : 

 b, after 48 hours. (Fliigge.l 



inoculation to obtain cultures of specific and isolated forms with 

 their characteristic appearances, is one of the essential methods 



