FURTHER CHANGES IN THE SAP. 1 99 



moves away from the chlorophyll corpuscles the starch 

 grains or carbon food (p. 197) mixed up or dissolved 

 in it are carried with it. Thus, as it passes through 

 certain cells and vessels through the plant, the food 

 taken up in liquid form from the earth and in gaseous 

 form from the atmosphere all works in together ; and 

 new substances are formed or old ones added to as 

 the case may be. These further changes are called 

 by one name, " metastasis"* In this way the proto- 

 plasm of plants is nourished, and so the living cells 

 and vessels of plants increase and cause the tissues, 

 that is the plant, to grow. In this way are formed the 

 solid crystals, as well as starch and oils and other 

 things, about some of which I told you in the last 

 chapter. 



In this way food is stored up in certain parts of 

 plants for future use. Easy examples of this are 

 found in tubers, tubercles, rhizomes, bulbs, and seeds. 

 They contain, as you know, stores of food ready to 

 support the growth of the young plant until by its 

 own roots and other organs it can take in fresh 

 food to supply its daily need. 



-Now what I want you to remember is that plants 

 can feed upon elementary substances, which you and 

 I and animals cannot do. Carbon, for instance, is an 

 elementary substance that is chemists cannot separate 



* From the Greek " me fa" over, and " stasis," a placing or setting 

 (fr : " histemi" I stand). A removal or alteration. It is also called 

 " metabolism." 



