GRAM S METHOD OF STAINING 2'] 



under the tap, dry, and mount. Organisms which retain Gram's 

 stain will be violet, almost black, organisms which do not will be 

 red. Pus, blood, etc., if present, will also be red. This counter- 

 staining by means of a good contrast stain is really almost a 

 necessary sequel to Gram's method, and in practical diagnostic 

 work the two almost always go together. 

 Dry and mount as before. 



The following important bacteria stain by Gram's method : 

 Staphylococci. 

 Streptococci. 

 Pneumococci. 

 Sarcinse. 



The skin coccus (M. epidennidis). 

 The bacillus of anthrax, 

 diphtheria, 

 tetanus, 

 tuberculosis, 

 leprosy. 

 Boas-Oppler. 



The various species of actinomycosis fungus or streptothrix. 

 The fungi of ringworm, favus, etc. 

 Yeasts. 



The following important pathogenic bacteria do not stain by 

 Gram's method : 

 The gonococcus. 

 The meningococcus. 

 Micrococcus catarrhalis. 



The pneumo-bflcillus (Friedlander's bacillus). 

 The Bacillus coli communis. 

 The bacillus of glanders. 



„ typhoid fever. 



,, influenza. 



plague. 

 „ soft sore. 



The Bacillus fusifovmis. 

 The vibrio of Asiatic cholera. 



The spirilla or spirochsetes of relapsing fever, syphiHs, and 

 Vincent's angina, and all other parasitic protozoa. 



