AND OF EXPOSED MUCOUS MEMBRANES. 577 



one hundred and twenty-seven individuals examined. Miller also 

 has rarely found the pus cocci in the mouths of healthy persons. 

 Streptococcus pyogenes was not found by Vignal in his extended 

 researches. The experiments of the writer, of Vulpian, Frankel, 

 iSTetter, Claxton, and others show that the micrococcus which in 

 1885 I named Micrococcus Pasteuri, and which is identical with the 

 ' ' diplococcus pneumonise " of German authors, is frequently present 

 in the healthy human mouth now called Micrococcus pneumonise 

 crouposse. Netter examined the saliva of one hundred and sixty-five 

 healthy individuals and obtained it in fifteen per cent of the number 

 examined. 



Another pathogenic micrococcus which is frequently present in 

 the mouths of healthy persons is the Micrococcus tetragenus of Koch. 

 The following pathogenic bacteria have also been isolated and de- 

 scribed : Bacillus crassus sputigenus (Kreibohm), Bacillus salivarius 

 septicus (Biondi). The Streptococcus septo-pyaemicus of Biondi is 

 described as having characters identical with those of the Strepto- 

 coccus pyogenes of Rosenbach. Two other pathogenic species de- 

 scribed by Biondi were each found in a single case only. Miller 

 has described the following pathogenic species isolated and studied 

 by him : Micrococcus gingivse pyogenes, Bacterium gingivse pyo- 

 genes, Bacillus dentalis viridans, Bacillus pulpse pyogenes. 



Vignal has tested a considerable number of microorganisms, ob- 

 tained by him in his cultures from the healthy human mouth, with 

 reference to their peptonizing action upon various kinds of food, with 

 the idea that some of them may have an important physiological 

 function of this kind. Out of nineteen species he found ten which, 

 after a longer or shorter time, dissolved fibrin, nine which dissolved 

 gluten, ten which dissolved casein, and five which dissolved albu- 

 min ; nine changed lactose into lactic acid, seven inverted cane sugar, 

 seven caused the fermentation of glucose, and seven coagulated 

 milk. 



Recently (1891) Sanarelli has shown that normal saliva has the 

 power of destroying the vitality of a limited number of certain patho- 

 genic bacteria, including the following species : Staphylococcus pyo- 

 genes aureus, Streptococcus pyogenes, Micrococcus tetragenus, 

 Bacillus typhi abdominalis, Spirillum choleras Asiaticse. When to 

 ten cubic centimetres of saliva, sterilized by filtration through porce- 

 lain, the above-mentioned pathogenic bacteria were added in small 

 numbers by means of a platinum needle carried over from a pure 

 culture, no development oscurred, and at the end of twenty-four 

 hours the bacteria introduced were incapable of growth in a suitable 

 medium. But when this amount of filtered saliva was inoculated 

 with a large platinum loop an ose a certain number of the bacteria 



