1914) 
NOLTE—SALIVARY ORGANISMS AND AIR POLLUTION 61 
—sugars, etc., none of the coccus forms produced gas. АП but 
one of the salivary cocci produced acid in the lactose medium, 
whereas none of the air cocci and but one of the skin forms 
deported themselves in this manner. This marks lactose broth 
as another medium of differential value. 
The salivary cocci with but one exception produced acid 
in saccharose, the single exception being the organism which 
produced no acid in the lactose medium. Two air cocci and 
one skin form also produced acid in saccharose, but notwith- 
standing these exceptions, it appears that saccharose is a third 
valuable differential medium. In the mannite, salicin, inulin, 
sorbite, raffinose, and rhamnose broths none of the organisms 
produced acid, thus marking these organic substances as of 
no value in differentiating the types of cocci under investigation. 
SUMMARY 
In reviewing the preceding discussion of results we find 
three media, namely, lactose and saccharose broths, and milk, 
which are of value in differentiating the cocci most character- 
istic of saliva from those of the air and the skin. One of the 
salivary coccus forms did not produce acid in lactose and 
saccharose broths and formed neither acid nor clot in milk. 
This may have been, and probably was, an air or skin form. 
Among the air cocci are two which vary somewhat from the 
remaining air and skin forms in that they produce acid in 
saccharose broth. Neither of them, however, produces acid 
in lactose broth, nor acid or clot in milk and in these respects 
they differ markedly from the characteristic salivary forms. 
Of the skin cocci one gave the characteristic reactions of the 
salivary organisms, and it is not at all unlikely that this was a 
salivary coccus. In general, then, it appears that the organism 
most characteristic of saliva is a coccus form which produces 
acid in lactose and in saccharose broths, and acid and clot in 
milk. 
FURTHER TESTS 
To further test the validity of the reactions above referred 
to as furnishing a reliable means of differentiating between 
salivary cocci and those of other origin, two additional samples 
of saliva, from two different individuals, were examined,— 
