CHAPTER II 



THE PLANT AND WATER 



* 



Kinds of Plant Foods. We have already seen that 

 the seed furnishes the food for the little plantlet until 

 it is large enough to get food from the soil, in much 

 the same way that the mother cow furnishes milk for 

 her calf until the calf is large enough to find its own 

 food. If asked, "What are the foods which a cow 

 eats ?" you would probably answer, "Grass, hay, straw, 

 oats, bran, etc." Not many of us could answer 

 so readily if asked to give a list of plant foods. There 

 are but a dozen of them, and half of these are nearly 

 as well known to you as cattle foods. The most 

 familiar are : water, lime, iron oxide,* soda.f ammonia, 

 and sand.J The other six are : magnesia, potash, car- 

 bon dioxide, and three acids, viz. : phosphoric, hydro- 

 chloric, and sulphuric. 



Plants and Water. Now let us consider these plant 

 foods. Every one knows that plants cannot live with- 

 out water, but few persons stop to think of the enor- 

 mous amount of water consumed daily by an acre of 

 growing vegetation. You may make this experiment : 

 Put exactly the same amount of water in each of two 



* Iron-rust, t Ammonia contains the element nitrogen, t Silica. 



