The Plantlet. 41 



mainly of cells containing starch grains and oil drops, 

 which serve as food for the plantlet during germina- 

 tion, since active protoplasm cannot exist without nour- 

 ishment (13). In the pea, bean, pumpkin and other 

 seeds of this class, the food supply, instead of being 

 stored by itself, as in the corn-grain, is contained 

 within the plantlet or embryo mainly in the fleshy 

 cotyledons. When the food supply of the seed is sep- 

 arate from the embryo, as in corn and many other seeds, 

 it is called the endosperm. 



It is the food supply of seeds that makes them so 

 valuable as food for animals. 



55. The Plumule (plu'-mule). If we look between 

 the cotyledons of the bean plantlet (Fig. 9), at the point 

 of their union with the hypocotyl, we may see a pair 

 of tiny leaves, and by carefully separating these if need 

 be, with the point of a pin, we may discover a minute 

 projection the growing point (66) of the stem between 

 them. These leaves, with the growing point, form the 

 plumule the terminal bud of the plantlet. These tiny 

 leaves become the first true leaves, and the growing 

 point between them develops into the stem and later 

 leaves. By close examination we may make out the 

 plumule in Figs. 8, 10 and 11. In the pea and corn, 

 it has already made considerable growth. 



56. Thus we see that the plantlet or seedling con- 

 sists of three parts, viz., the hypocotyl, the cotyledons 

 (in some plants cotyledon) or seed-leaves, and the plu- 

 mule or terminal bud. 



57. Chlorophyll (chlo'-ro-phyll). Soon after the 

 plantlet emerges from the seed-case, a green color ap- 



