THE BACTERIA OF THE MOUTH 93 
Inoculate from the unnamed cultures furnished such media 
as the requirements of the next exercise demand. 
142. 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 in the same manner as 
is sputum. 
