EFFECT OF LIGHT ON VEGETATION 
103 
conditions, but not rushing from one thing to another as a success¬ 
ful plant must in arctic conditions. 
The importance of length of daily illumination ranks with in¬ 
tensity of light, water supply, temperature and soil conditions as 
a factor determining plant development. 
The manufacturing processes carried on in green leaves of plants 
stands alone in efficiency and in importance of the product made. 
The original statement stands—the greatest factory in the world is 
the green leaf of the plant. 
Persis S. Crocker. 
