EXAMINATION OF BACTERIA WITH THE MICROSCOPE. 43 



Bacillus of anthrax, 



Bacillus of tetanus, 



Bacillus aerogenes capsulatus, 



Ray fungus of actinomycosis. 



The following bacteria are not stained by Gram's method : 



Gonococcus, 



Diplococcus intracellularis meningitidis, 



Micrococcus melitensis, 



Bacillus of chancroid (Ducrey), 



Bacillus of dysentery (Shiga), 



Bacillus of typhoid fever, 



Bacillus coli communis, 



Bacillus pyocyaneus, 



Bacillus of influenza, 



Bacillus of bubonic plague, 



Bacillus of glanders (bacillus mallei), 



Bacillus of malignant edema, 



Bacillus of Friedlander, 



Bacillus proteus, 



Spirillum of Asiatic cholera, 



Spirillum of relapsing fever. 



Staining the Bacillus of Tuberculosis. A very large 

 number of methods have been proposed for staining the 

 bacillus tuberculosis, all of which depend upon the princi- 

 ple that, after adding to solutions of aniline dyes certain 

 substances, like aniline-water, carbolic acid, or solutions 

 of ammonia or soda, the bacillus tuberculosis is stained 

 with great intensity, and gives up its stain with difficulty. 

 Solutions of acids will remove the stain from all parts of 

 the preparation excepting from the tubercle bacilli, which 

 retain the dye having once acquired it. The rest of the 

 preparation may now be given a different color contrast- 

 stain. 



Bacilli that resist decolorization by acids are called acid- 



