THE FERTILITY OF SOILS IN THE TROPICS 



37 



cultural returns. This is clearly represented in the dotted 

 line in Diagram I, which shows the variation in volume 

 during a normal year as the river enters Egypt at Wadi 



MAP OF NIT.F, BASIN. 



Haifa. It will be seen that during the early months the 

 volume is steadily -falling till it reaches a minimum of 

 about 600 cubic metres per second at about the end of 

 May, that during the next two months it rapidly rises- 



