BACTERIA IN PROCESSES OF NATURE. 
could not live without them. They live upon 
dead organic matter, and by their activities de¬ 
composition, fermentation and putrefaction are 
produced. Nourishment necessary to the suste¬ 
nance of vegetable life is derived from carbonic 
acid gas, ammonia and water, which are all pro¬ 
duced by the action of saprophytic bacteria on 
dead animals and vegetables. Vegetable and 
plant life would cease to exist if the carbon and 
nitrogen to which they owe their growth and de¬ 
velopment could not be obtained from this source. 
Animal life is sustained by the oxygen thrown 
off by trees and plants and to a certain extent by 
the food obtained from the vegetable world; 
therefore, the work of the saprophytes is neces¬ 
sary to the existence of all forms of life. 
With regard to the work of saprophytes as our 
friends in the processes of Nature, let us look a 
little farther into this phase as explained to us 
by scientists. Let us see why it is that they play 
so important a part in these processes, and how 
it is that they arc so completely interwoven with 
the vital powers of nature, that life in all its 
forms would vanish from the earth should their 
activities cease. 
When as children we explored the woods and 
perched ourselves upon fallen tree trunks and 
saw them dropping into decay, how many of us 
now studying bacteria in regard to their connec¬ 
tion with our work as nurses ever associated the 
process of decay with the activities of germs? 
To-day we are taught that bacteria play an im¬ 
portant part in this process after the hard, woody 
substance of the tree has been softened and pre¬ 
pared for their work by moulds. Then, after the 
23 
Bacteria in 
Natural 
Processes. 
Decay of Trees 
and Plants. 
