EXPERIMENT STATION BULLETINS. 



447 



It was manifestly impossible to select at the beginning of the experi- 

 ment, four hundred stalks that should grow so evenly that those cut at the 

 different intervals would fairly represent the stage of growth in the field 

 at large at the given time, the number taken w y as too small for that. It 

 was fair to assume, however, since representative stalks were taken, that 

 these plants so selected would give a clue as to the changes that were 

 taking place in the relation of parts. Dividing, therefore the weight of the 

 leaves, of the stalks and of the ears separately by their united weight 

 for the given date we get the per cent of the gross weight of the plant 

 that was resident in the leaves, stalks and ears respectively, hence this 

 table which shows the per cent of the whole weight found in each part. 



Per cent of total weight found in leaves, stalks and ears. 



It is uot the total weight that interests us, however, but the proportion 

 of dry matter that is found in the leaves, stalks and ears respectively. 

 Hence in the chemical analysis each part was thoroughly dried and the 

 following table shows the proportion of the dry matter of the whole 

 plant that was included in each part. 



Per cent of total dry matter resident in leaves, stalks and ears, respectively. 



The relation of the weight of the stalk to that of the entire plant remains 

 about constant. The relative weight of the ear increases rapidly while 

 that of the leaf as rapidly decreases. Nevertheless less than half of the 

 total dry matter in the plant when fully ripe is in the ear, nearly a third 

 of it is in the stalk and over a fifth is in the leaves. 



Going back in the history of the plant, it is to be noted that as far as dry 

 matter was concerned, on August 24th, when the corn was in the milk, a 

 little more than a third of the food material was contained in the leaves, a 

 slightly less proportion in the stalks and still less in the ears. A week 

 later, on August 31st, while still more than a third of the dry matter was 

 in the leaves there was but practically a quarter of it in the stalks and 

 slightly over forty per cent in the ears which were evidently growing par- 

 tially at the expense of the stalk. A week later when the corn was just 

 glazing the leaves contained less than a third, the stalks a quarter and the 

 ears 44 £ of the dry matter of the crop. Even when fully matured and 



