THE SEED, GERMINATION AND THE PLANTLET 33 



cannot exist without nourishment (13). In the pea, bean, 

 pumpkin and other seeds of this class, the food supply, in- 

 stead of being stored by itself, as in the corn grain, is con- 

 tained within the plantlet or embryo mainly in the fleshy 

 cotyledons. When the food supply of the seed is separate 

 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. If we look between the cotyledons 

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

 with the root, 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. Parts of the seedling. Thus we see that the plant- 

 let or seedling consists of three parts, viz., the root, the 

 cotyledons (in some plants cotyledon), or seed-leaves, 

 and the plumule or terminal bud. 



