in DEVELOPMENT AND ENVIRONMENT 73 



Ten days July August September October November Dec. 



ending 10 20 30 9 19 29 8 18 28 8 18 28 7 17 27 7 



Flowering 



ciO-2 



0. 



ci 



. 



V? 



~E~ 



~B^ 



Soil -surf act 



R.L-18-8m. 



^-90% 

 70% 



o* 



50 % 



4O% 

 C0/ 



Boiling 



Shedding ; 



Percentage of 



Shedding tc 



Flowers 



** 4ttff.tsf. 



FIG. 47. TERRACED LAND. GIZA. 1909. 



Three terraces, each 40 cm. lower than predecessor. 



Observations on 100 plants in each terrace ; flowers counted every day, bolls 

 every tenth day, shedding by subtraction. 



