178 MICROBES, FERMENTS, AND MOULDS. 
supposed to be the cause of the early decay of teeth, 
especially in children who eat them in excess. 
The microbe which Miller has 
found to be most common in de- 
cayed teeth is very polymorphic. 
Microccocus, bacterium, chains and 
filaments, are only different phases 
of the same plant, which also pro- 
duces acid fermentation in the 
mouth, and the formation of lactic 
acid. Within the dentine tubules, 
a section examined under the 
microscope shows all the inter- 
mediate stages between the isolated 
"Gris In the. dentine micrococcus and the filaments 
b, spontaneous caries. (Figs. 81, 82). Miller succeeded 
in producing this disease in sound teeth artificially. 
; 
6 
i at oe 
0 § H \e 
0 ° o CY 
% %, 2 eats 
G.-re 2 Sav 
Qe 
pee 
co? 
o 
oOo 
oO 
o 
° 
» 
fo) 
Fig. 82.—Bacterium of dental caries ae b, different forms obtained in gelatine 
culture, 
According to his experiments, the best dentifrice for _ 
