56 MAN, — THE ANIMAL 



tion that our Interest lies, but in the changes that 

 take place within them. When water (a chemical 

 compound, H2O) and carbon dioxide (a chemical 

 compound, CO2) both enter a chloroplast in the 

 daytime, a series of chemical changes follows that 

 results in the production of carbohydrates. 



This chemical body possesses more energy than 

 was present in either water, carbon dioxide, or 

 both. This new chemical body thus formed can 

 do more work than the bodies from which it is 

 formed. In the manufacture of this food, the sun 

 furnishes the heat and light energy that is neces- 

 sary. Science has been unable to detect as yet just 

 what amount of energy or effect the living proto- 

 plasm contributes to this process that has such 

 far-reaching influence on all forms of life. After 

 the simple sugars have been formed in the chloro- 

 plast, the surplus of material thus manufactured is 

 further modified by the living protoplasm of the 

 plant into either fats such as oils or into proteins 

 by joining nitrogen and sulphur to the sugar mole- 

 cules. The details of these changes are for the 

 most part unknown. (Figure 16.) 



The net result of the changes that occur in the 

 living cells of plants containing chlorophyll is that 

 a given amount of energy has been captured, re- 

 combined, and put into such form that living things 

 can use it. A daisy and a bean growing in the 

 same field have these chlorophyll bodies and both 



