FERMENTATION OF CARBOHYDRATES 



85 



Another is in the formation of the "holes" or "eyes" so 

 characteristic of Swiss and other types of cheese (Fig. 63). 



A great many organic acids are formed during the "acid 

 fermentation" of carbohydrates by bacteria. Each kind of 



Fig. 61. — A "flowing" oil well. 



bacterium, as a rule, forms several different acids as well as 

 other substances, though usually one is produced in much 

 larger amounts, and the kind of fermentation is named from 

 this acid. One of the commonest of these acids is lactic. 



