CHAPTER II 



THE SEED 



Parts of the Seed. A seed is a reproductive structure, 

 composed of the embryo, seed coats, and sometimes an 

 endosperm. 



Embryo. The embryo is the young plant, in the seed. 

 Its parts are the radicle, the cotyledons, and the plumule. 

 The radicle becomes the root of the plant, and the plu- 

 mule becomes the shoot. 



Seed Coats. The seed coats consist of an outer coat 

 and an inner coat, and are to pro- 

 tect the embryo. The outer coat, 

 called the testa, is always hard; 

 the inner coat is called the teg- 

 men. In some seeds the inner 

 and the outer coats cannot be sep- 

 arated. There is a hole through 

 the seed coats called the micro- 

 pyle, by which water can enter 

 the seed. Through this hole the 



radicle comes when the seed germinates, or begins to 

 grow. 



Endosperm. Some seeds, such as the seed of the coconut 

 palm, and of maize, contain a store of food outside the em- 

 bryo, but inside the seed coat ; this part of the seed is called 



micropyle 



radicle 



inner coat 



" cotyledons 

 Fir.. 9. Parts of a seed 



