32 THE PLANT. 



American planter, who cultivates his plants upon a field 

 that has never been manured. The one seeks to reduce 

 or dilute the narcotic, sulphureous, and nitrogenous con- 

 stituents of the leaves; the other to concentrate them. 

 Accordingly, the American planter breaks the lower leaves 

 in their full vigour, when the plant has attained to half- 

 growth ; the European planter attaches the greatest value 

 to the fully-developed upper leaves. 



As the tobacco plant, like all annuals, only yields up 

 its whole store of organisable matter at the ripening of 

 the seeds, the stem does not die after the loss of the 

 leaves ; but the materials still remaining in it and in the 

 roots cause the stem to send forth fresh shoots, and fre- 

 quently even leaves, though small-sized ones. In the 

 West Indies, Maryland, and Virginia, before the gathering 

 of the leaves, the stems are notched immediately above 

 the ground, so that they lean over without being severed 

 from the root. In warm weather, the water in the leaves 

 evaporates, and a motion of the sap ensues from the stems 

 and roots towards the leaves, m which the sap is thus 

 concentrated as the plant withers. The tobacco planters 

 on the Eliine have found that a superior tobacco, poorer 

 in albumen and nicotine, is produced if, instead of breaking 

 the leaves off in the field, the plant with the leaves on it 

 is cut down just above the ground, and hung up to dry 

 with the top downwards. The stem will, under these 

 circumstances, continue to vegetate for a time, sending 

 forth small shoots which gradually turn in an upward 

 direction and put forth flower-buds. In these flower-buds 

 the sulphureous and nitrogenous constituents are collected 

 from the leaves, which lose these ingredients in the same 

 proportion, and are thereby improved in quality. 



Of the plants cultivated for the sake of their seed, 

 wheat holds the chief place. 



