SPRING BLOSSOMS. 215 



are the real mouths and stomachs and digestive 

 oigans of the vegetabl economy. The business 

 of the root, wliich most people used to imagine 

 was entirely intended for sucking up the nutri- 

 ment of the plant, consists really for the most part 

 in the mere subordinate function of water-supply. 

 The real raw material of leaf and stem and flower 

 and fruit is ultimately derived from the carbonic 

 acid diffused in the gaseous condition through the 

 surrounding atmosphere. If this seems at first 

 sight a hard saying, we have only to remember 

 the familiar yet crucial instance of a hyacinth 

 grown in a glass vase filled with water. Here it 

 is quite clear, even to the most unscientific mind, 

 that the roots, which descend into the glass, can 

 supply the plant with nothing more than the 

 water they float in. It is the work of the leaves 

 to extract the solid particles of carbon from the 

 air around and to build them up with oxygen, 

 hydrogen, and nitrogen into the starches and the 

 active living principles which ultimately compose 

 the entire plant. Exactly the same sort of evi- 

 dence is afforded by the common cottage priictice 

 of growing mustard-and-cress in a saucer upon a 

 small piece of wetted flannel. It is quite evident 

 in such a case that the rootlets of the cress supply 

 the growing seedlings only with the water which 

 they absorb from the flannel on which they creep, 

 while the entire work of collecting material for 



