206 The Development of the Grain of Wheat 



nitrogen in the grain and the nitrogen-phosphoric acid ratio. It has 

 often been supposed that the extent to which the plant can utilise 

 nitrogen in the soil is dependent upon the phosphoric acid also present, 

 because the phosphoric acid acts in some way as a carrier of nitrogen, 



Plot 3 

 R.F. 



6 9 12 15 18 21 24 27 30 33 36 39 days 



Fig. 9. Actual ash in 1000 grains, 1907 and 1908. 



R.F. 

 Plots 



:L::xJ Plot 10 



6 9 12 • 15 18 21 24 27 30 33 36 30 days 



Fig. 10. Actual P0O5 in 1000 grains, 1907 and 1908. 



