464 



Messrs. A. D. Hall and C. G. T. Morison. 



[Dec. 22, 



Perhaps the most important point brought out is that the grain establishes 

 a particular composition at an early stage in its development, after which, 

 although it continues to grow and increase in weight, it does not sensibly 

 alter its composition. From July 18 onwards the percentage of nitrogen and 

 the percentage of phosphoric acid in the grain remain approximately 

 constant, though the grain gains a further 50 per cent, of its weight during 

 the same period. Whatever chemical changes take place during the latter 

 stages of ripening, they consist in the rearrangement of the minerals within 

 the grain rather than in any progressive change in the character of the 

 intake. 



20 27 July 4 II 18 25 Awgl 



Fig. 3. — Dry Weights of plots without Potash. 



Whole 

 plank 



Grams 

 300 



Whole 

 'plant 



27 July 4 u 18 25 Awg.i 



Fig. 4. — Dry weights of plots with Potash. 



Taking these mean figures as indicating the normal course of development 

 it will now be possible to review the results yielded by individual plots and 



