CONDITIONS OF GROWTH. 57 
temperature near that of the body. for their develop- 
ment, while many saprophytic bacteria can grow only 
at much lower temperatures. Bacteria when exposed 
to lower temperature than suffices for their growth, 
while having their activities decreased, are not other- 
wise injured; while exposure to higher temperatures 
than allows of growth destroys the life of the bacteria. 
The relations of the temperature to bacterial life and 
death will be dealt with fully in a later chapter. 
