124 THE VEGETATIVE FUNCTIONS OF PLANTS 



vided for in many v/ays. Young embryo plants in the 

 seed find a rich supply of nourishment, ready made by the 

 parent plant, stored within their tissues (as in the bean 

 or pea), or around them (as in the corn, or castor-oil seed, 

 Fig. 83). They do not have to manufacture their own 

 food at first. Young and rapidly growing plants (seed- 

 lings and young saplings) have much larger leaves than 

 mature plants of the same species (Fig. 55). On this 

 account food making, from the raw materials taken in 

 by the plant, may proceed much more rapidly. Plants 

 commonly store food in quantity where it will be needed 

 in the future by rapidly growing new parts, and such 

 storage organs usually become swollen by the abundance 

 of stored food. This is illustrated by ''potatoes," which, 

 as is well known, are underground branches (tubers) stored 

 with food for the use of young sprouts when they begin 

 to grow in the spring. All bulbs are to be interpreted in 

 the same way. Farmers recognize the need on the part 

 of growing plants for an abundance of food, when they 

 fertilize their fields, thereby placing in the soil a rich 

 supply of the raw materials out of which the growing 

 crops can manufacture food to meet their needs. 



