TYPES OF BACTERIA FOUND IN MILK. 149 
Europe sour milk is commonly used as a beverage, and has been 
highly recommended as a healthful drink. It is claimed that the 
lactic acid, present in abundance in these sour milks, has a very 
beneficial action in the intestine, preventing the growth of the com- 
mon putrefactive germs, and serving in general as a corrective for 
various intestinal disturbances. It is not ordinary sour milk that is 
FIG. 33. Curds from two lots of milk soured by a gas-forming and a 
non-gas-forming bacterium. 
especially recommended for this purpose, but a special form, found 
most common in Bulgaria, and used veiy widely as a drink in that 
country. Such milk contains a variety of lactic acid bacterium 
very different from the two above described, and deserving to be 
called a distinct type. It is in the form of a long, large rod (Fig. 34), 
which frequently forms long chains. It differs from the more com- 
mon type in producing a much larger quantity of lactic acid. The 
