GROWTH ON DIFFERENT CULTURE MEDIA 209 



On agar and gelatin plates made so that the colonies are 

 well isolated, the form of the latter, the rate of their growth, 

 the character of the edge and of the surface, the elevation 

 and the internal structure as determined by a low-power 

 lens are often of almost diagnostic value. Also in the case 

 of the gelatin plates, the character of the liquefaction 

 is important. Figs. 157 to 165 show some of the commoner 

 characteristics to be noted. 



14 



