THE BEGINNINGS OF PLANT LIFE 
is rather unstable, both physically and chemically. Ex¬ 
tremely simple and very small organic bodies may form 
themselves from inorgmic colloids under the influence of 
sunlight, and from these in turn, reacting upon one an¬ 
other, may develop more and more complex organic com¬ 
pounds. As this complexity increases, the bodies acquire 
the ability to utilize light-energy for further develop¬ 
ment of structure. In this manner, the gulf between non¬ 
living and living things must have been bridged and a 
spontaneous emergence of life occurred. At just what 
point these structures ceased to be mere organic com¬ 
pounds and became living organisms we cannot be sure; 
but we are convinced that these first living organisms did 
not stand even at the level of bacteria, but at a level of 
life far below anything the microscope can reveal. 
The next stage in the evolution of life is probably to 
be found in those bacteria which can grow on inorganic 
substance and synthesize proteins and carbohydrates from 
carbon dioxide, inorganic nitrogen, and sulphurous and 
phosphorus compounds. The step from such synthesizing 
bacteria to algae which contain chlorophyll probably fol¬ 
lowed next, and with the coming of the chlorophyll to 
utilize the sun’s energy, life on a large scale became pos¬ 
sible for the plant kingdom. 
The places where life sprang up and gradually formed 
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