CHAPTER V 

 PLANT SUBSTANCE 



37. The Body of a Plant, including stem, root, seeds, 

 etc., is composed chiefly of framework material and 

 reserve food. The framework material is never used 

 by the plant for any other purpose. The reserve food 

 contains a variety of substances. Sometimes this re- 

 serve food is separated by mechanical means in an 

 almost pure condition, such as starch from corn and 

 potatoes, cooking oil from cotton seed, linseed oil from 

 flax seed, castor oil from castor beans, corn oil from 

 corn, and peanut butter (a thick oil) from peanuts. 

 When the starches and oils are thus removed, there 

 still remain the bran and meal, which contain a variety 

 of food substances. 



38. In Germinating Seeds, all the reserve food may 

 be used to nourish the young plant. The substances 

 in the thick cotyledons of the bean were seen to wither 

 away as the seedling grew. The store of food for the 

 young plant in the seed was put there by the parent 

 plant. A corn grain will produce from one thousand 

 to two thousand* seeds and a large stalk. Where does 

 the seedling get all the food materials to nourish so 

 large a stalk, and lay up a large store for so many other 

 seeds? Before we answer this question, we will try to 

 find out something of the nature of the substances in 

 plants. 



39. Composition of Plant Substance. Chemists have 

 ways of separating the various substances found in 



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