226 BACTERIA. 
of an hour, in four at the end of a second hour, in eight 
in three hours, ete., will in twenty-four hours amount to 
more than sixteen and one-half millions. Bacteriwm 
termo, a common species, whose cells measure only one- 
twenty-thousandth of an inch in diameter multiply so 
rapidly that, at the end of a second day, they will fill 
a pint measure, and the same conditions being con- 
tinued, the bacteria issuing from a single germ would 
fill the ocean in five days. 
Of course it is impossible that these conditions shall 
ever arise. Owing to the nice adjustment of the powers 
of nature, no one form of life is able so completely to 
overpower the others,—still, bacteria are more widely 
dispersed and more numerous than all other living 
things put together. They resist the greatest extremes 
of heat and cold, and are known to live for years and 
then germinate with unimpaired vigor. 
So much is said and written nowadays of the germ 
theory of disease that people associate bacteria only 
with thoughts of dirt, of disease, of death and decay, 
yet, in the great economy of nature, they have a work 
to perform—and that a very important one. In the or- 
ganic world, change is the constant law. Our physicians 
tell us that our bodies are undergoing ceaseless changes. 
With each successive activity of mind and body a cer- 
tain amount of material is used up. Everywhere in 
nature do we see these changes going on. Life is pro- 
eressive and ever seeks new material upon which to 
work. Nature repeats herself in ever-recurring cycles. 
While life remains in a body, the vital principle has 
control of these changes ; but it has been shown that 
organic matter, once dispossessed of the principle of 
life, cannot again enter into the general circulation, 
until it has been disintegrated, and returned to the or- 
ganic world. This work isrelegated to the lower fungi. 
Their germs are about us everywhere ; in the earth, in the 
110 
