PATHOGENIC BACTERIA. 279! 



SOLUTION No. i. 



Methylene-blue I 



Alcohol (96 per cent. ) 20 



Distilled water 95 



Glacial acetic acid 50 



SOLUTION No. 2. 



Bismarck brown I 



Boiling distilled water 500 



Stain the cover-glass preparation which has been fixed 

 in the flame in No. i one to three seconds ; wash in water ; 

 stain in No. 2 three to five seconds; wash in water; mount 



FIG. 76. 



* -*j -* 



[ r O, ' \ v . 





Bacillus of diphtheria. (X 1000.) 



as usual. The body of the bacillus is stained pale brown, 

 with dark blue spots, especially at the ends. (Fig. 77.) 



The diphtheria bacillus is peculiar in staining irregularly ; 

 certain spots stain more sharply than other portions, and 

 darkly-stained spots are likely to occur at the ends. It is 

 facultative anaerobic. It grows most rapidly in the incuba- 

 tor, and slowly, or not at all, below 20 C. Gelatin is not 

 liquefied. It may be cultivated on various alkaline culture- 



