124 



Under such circuinstances it is not surprising that the development 

 of the crop of grain keeps pace with the increase of the available 

 water, at least up to the point where the quantity of water is suffi- 

 cient to give a maximum crop. 



The supply of water has an influence not merely on the quantity 

 of the crop, but also on the rapidity of the development of the plant. 

 Wollny (1881) shows that in general the grain ripens sooner as the 

 quantity of water diminishes. This is well seen in the following series 

 of experiments (Table 62) on the time of ripening of grain in fields 

 that are sown more or less thickly. The thickly sown fields correspond, 

 of course, to a less quantity of water available for each plant. 



WINTER RYE ( WOLLNY, 1875-76). 



PEAS (WOLLNY. 1877). 



Similar experiments were made by Wollny on the Ramersdorfer 

 variety of potatoes. A plat containing 1 phmt to 4,435 square centi- 

 meters ripened by the end of September (1875), but a plat containing 

 1 plant to 812 square centimeters ripened the 1st of August, and 

 other plats containing 1 plant to 2,500, 1,600, 1,109 square centimeters, 

 respectively, ripened at dates proportional to the area occupied 

 by each plant. As each plat received the same amount of sunshine 

 and of water, the dates of ripening must have been hastened in pro- 

 portion as the number of plants in each plat were increased. 



