96 GROWTH AND WORK OF PLANTS 



estimates, a sunflower 6 feet high transpires on the average about 

 one quart per day; an acre of cabbages 2,000,000 quarts in four 

 months; an oak tree with 700,000 leaves transpires about 180 

 gallons of water per day. According to von Hohnel, a beech tree 

 no years old transpired about 2250 gallons of water in one sum- 

 mer. A hectare of such trees (about 400 on 2\ acres) would at 

 the same rate transpire about 900,000 gallons, or about 30,000 

 barrels in one summer. 





