90 LUTHER BURBANK 



work because no one knows just how their work 

 is performed. 



That is to say, no one at all understands why 

 it is possible for the plant cell that bears within 

 its substance one of these green chlorophyll 

 bodies to combine certain inorganic elements into 

 nutritious foods, a feat that no human chemist 

 can perform. 



But, on the other hand, w T e do know, thanks to 

 the analysis of the chemist — who can sometimes 

 tear things to pieces and find out what they are 

 made of even when he cannot put them together 

 again — what the chlorophyll granule accom- 

 plishes, even though we cannot understand just 

 how or why it is able to perform its work. 



Chlobophyll at Woek 



What takes place within the structure of the 

 leaf, then, with the aid of the wonderful green 

 workmen, is this : A certain number of molecules 

 of water, brought to the leaf from root and stem, 

 are taken in hand and compounded with a certain 

 number of molecules of carbon extracted from 

 the air that has been brought into the leaf labor- 

 atory through its mouths or stomata from the 

 outside atmosphere. 



When the compound has been effected, we 

 still have the atoms of hydrogen and oxygen 



