117 



The miinhor of rainy days was lar«2:e, but the rainfall was small, 

 and the plants in bod No. 1 sutiVrod for want of water. The relative 

 harvests for the ditferent beds and crops were as follows: 



Beds Nos. 1 and 2 showed about the same rate of growth. No. ?> 

 showed a retardation. The barley and the rye were harvested from 

 this bed four days later than from the other two. The quantity of 

 harvest increased with the quantity of water, and the harvest of 

 grain, except in the case of the wheat, was more increased by water- 

 ing than w^as the harvest of straw ; the quality of the grain show^ed 

 only slight differences. 



Hellriegel experimented (1867-1883) on the influence of w^ater 

 upon the crops. He filled a number of vessels with quartz sand and 

 maintained the earth at a different state of dryness. The exjDeri- 

 ments were repeated for several years on wheat, rye, and oats, the 

 general results being that wdien the ground contained from GO to 80 

 per cent of its full capacity of water the harvest was larger than 

 when the ground was drier and about in the following proportions: 



Hellriegel also varied the experiment by giving the tubs daily, 

 each evening, as much water as they had lost during the day, thus 



