VEGETABLE GARDENING | 55 
plows under a crop of corn or a dressing of farm 
manure, we know that it decays, that is, breaks up 
into simpler compounds, goes into solution in the soil 
water and is taken into the plant. All of this is made 
possible by bacteria. But let us bring the fact of the 
value of bacteria still closer home. When you eat your 
dinner, the food is digested in your stomach and intes- 
tines; part of this digestion is carried’ on by juices 
secreted there, but part of this work is carried on by 
bacteria. 
Let us remember then that there are good and bad 
bacteria. Bacteria that cause disease are bad; bac- 
teria which cause decay in the soil are good, as are 
those which help digest our food. 
These little plants do not ask where they may grow. 
If we leave meat, vegetables, milk or other food ex- 
posed to the air, they will start operations. 
The protection of food. How then may we protect 
our food from these plants? Like all other plants, 
they must have proper temperature, moisture, oxygen 
in some cases, and a suitable place in which to grow. 
The methods of food preservation depend upon inter- 
fering with one or more of these essential conditions . 
to their growth. The following practical suggestions 
are given by McConn* for preventing the growth of 
molds. 
1. Keep all food fairly dee 
2. Expose as much as possible to the light. 
3. Lower the temperature. 
Yeasts grow in food products in which the sugar con- 
tent is not too high, if kept in a warm place. The 
spoiling of food products due to the action of yeast is 
*Yeasts, Molds and Bacteria. , 
