THE FOOD OF PLANTS. 

 FIG. 21. 



133 



4 3125 



Water-cultures of Buckwheat, after Nobbe. 



No. i. Plant grown in normal saline solution. 

 2 - ,, without potassium. 



3- ,, with soda instead of potash. 



without calcium. 



without nitrates or ammonia salts. 



