16 BACTERIA 
HOW THEY GROW 
Warm milk is one of the best places in the world 
to grow bacteria. It is so nourishing and di- 
gestible that nearly all kinds of bacteria find 
milk exactly suited to their taste. When par- 
ticles of dust fall into milk, the crew of bacteria 
which they carry begin to multiply rapidly. Some 
feed on the sugar in milk and change it into acid, 
and this acid causes the milk to become sour. 
Others feed on curds and give milk a bad odor 
or make it decay. 
Cold weather stops growth of plants. Cold 
stops the growth of bacteria. Where it is as cold 
as ice or ice-water, bacteria grow scarcely at 
all. Warm weather with a temperature of blood- 
heat makes bacteria grow most rapidly. 
One germ will swell up, break in half, and in 
twenty-four hours double 48 times. If not inter- 
fered with, this means in forty-eight hours one 
germ would multiply itself to 281,474,976,710,656. 
DISEASE FROM MILK 
1. Typhoid Fever has destroyed the business 
of many dairy farmers. Typhoid in the farmer’s 
family or in hired help sometimes gets into the 
