THE SEED 3 



distinguished. Among the simplest and most easily 

 understood seeds are any of the ordinary peas or beans. 

 An examination of a very young plant of the French or 

 kidney bean one which has just made its appearance 

 above the surface of the soil will reveal the following 

 parts : two thick leaves (in the case of the scarlet runner 

 and some others, these leaves do not come above the 

 surface of the soil); between these there is a very small 

 leaf-bud with minute leaves, whilst below there is a 

 stem which terminates in a root, the root itself being 

 branched. 



The parts of the young bean plant should now be 

 compared with a bean seed which has not germinated, 

 but which has been soaked for a few hours in water in 

 order to soften it. The seed-coat will strip off without 

 difficulty, and it will then be found that enclosed by 

 the seed-coat is a structure which easily splits into two 

 halves, and a little thought will show that these two 

 halves correspond to the two thick leaves which have 

 been spoken of already. These leaves are called the 

 cotyledons or seed-leaves. Between the cotyledons there 

 will be seen a small curved body, one portion of which, 

 when the seed germinates, becomes the stem with leaves 

 upon it, while the remaining portion develops into the 

 root. These portions are known respectively as plumule 

 and radicle. With the help of a pocket lens, the 

 plumule is seen to consist of very small leaves folded 

 together. There thus exists in the seed a minute 

 plant with rudimentary root, stem, and leaves. When 

 seeds are placed under suitable conditions these rudi- 

 mentary organs grow, and the seed is said to germinate. 



