286 



SPECIFIC MICRO-ORGANISMS 



On other media, such as glycerin agar, the morphological irregulari- 

 ties are less marked as a rule. The organism in young cultures 



FIG. 116. Bacillus of diphtheria. X 1000. 



/ 



FIG. 117. B. diphtheria stained by Neisser's method. 



stains readily, best perhaps with Loffler's methylene blue in 

 the cold. It is Gram-positive. Old cultures stain with great 

 difficulty. 



