JOHN S. GOULD'S ADDRESS. 617 



delicate vessels of the germ. It does more than this ; after 

 having effected the solution of the starch, it converts it gradu- 

 ally into sugar, which is essential to the existence of the 

 young plant. When the starch of the kernel is wholly con- 

 verted into sugar, the first true leaves and the first true roots 

 appear, and henceforth it is fitted to draw its nourishment from 

 other sources ; it has entered on an independent existence. 



In the rapid sketch of the history of the growth of the corn 

 plant which I have laid before you, I stated that in eight days 

 after planting, the weight of the plants above the ground on an 

 acre, was 27|^ lbs. In forty-five days afterwards, their weight 

 was 5,139 lbs., and in ninety-one days after this, their weight 

 was 31,389 lbs. We perceive from these facts, that there has 

 been an average daily addition to. the weight of the plants of 

 231 lbs. 



It is a question of the greatest importance in practical agri- 

 culture, How can plants be made to take up and assimilate 

 the greatest possible amount of food ? We cannot answer 

 this question intelligently, before we have learned the sub- 

 stances which enter into the composition of the corn plant. 



When the leaves of the plants first appear, 89.6 per cent, of 

 their weight is water, 10.4 per cent, is dry matter, and of this 

 dry matter 13 per cent, is ash or inorganic matter. Hence the 

 plants on an acre, at the first formation of the leaves, contain 

 27 lbs. of water, 3.13 lbs. dry matter, and nearly half a pound 

 of ash. When the plants are in full flower, 87 per cent, of 

 their weight is water, 12.92 per cent, is dry matter, the ash 

 constituting 8.82 per cent, of the dry matter. Wiien the corn 

 is ripe, 61.20 per cent, of the weight of the plant is water, 38.79 

 per cent, is dry matter, and the ash is 4.1 18 per cent, of the 

 dry matter ; consequently the weight of the plants on an 

 acre is made up of 21,077 lbs. of water, 13,361 lbs. of dry 

 matter, and 549 lbs. of ash. The relative proportions of water 

 and dry matter remain very nearly the same in all the various 

 stages of the growth of the plant, until after the period of flow- 

 ering ; from thence the water regularly diminishes up to the 

 period of perfect ripeness. Something may be done by the 

 farmer to furnish this large amount of water, but his main 

 business is with the supply of the dry matter. This dry mat- 

 ter is composed of two distinct substances, one of which may 

 78 



