106 LABORATORY BACTERIOLOGY 



organism. Note the name of the genus to which each colony 

 belongs, together with the approximate number of colonies of 

 each. 



Make one or more cover-glass preparations from the mouth 

 and stain with alkaline methylene blue. Note carefully the 

 varieties of bacteria they contain. 



Inoculate from the unnamed cultures furnished such media 

 as the requirements of the next exercise demand. 



155. Making cover-glass preparations from the mouth. These 

 can be made from the sputum, expectorated in a watch glass, 

 or from the scrapings from the tongue, gums, pharynx, or from 

 the base of the teeth. If any of the latter sources is chosen, 

 the part from which the material is to be taken should be 

 scraped carefully with a sterile (flamed) platinum loop or with 

 the blunt point of a scalpel or other stiff instrument. The 

 scrapings are spread on cover glasses the same as the sputum. 



