HOW A PLANT GETS OUT OF THE SEED. 1Q 



ren are comfortable. At night the box should not be allowed 

 to become cold as this will retard the germination. If the room 

 becomes cold during the night protect the box by covering, or 

 keep in a warm place. Watch changes from day to day and 

 note when the first plants appear above the ground. 



1. BEAN. The first thing observed in the bean is a small arch, 

 neither the seed-coat or seed leaves can be seen, but a little later 

 the large, fleshy seed-leaves partially show. In some cases the 

 seed-coat may remain attached but generally this remains in the 

 soil. As the young plant has pulled itself out of this protecting 

 covering the seed-leaves and stem soon straighten up. The small, 

 delicate plumule spoken of in connection with the seed is much 

 longer and may be seen beyond the cotyledon. A little later the 

 seed-leaves are pointed upward. The plumule consists of two 

 expanded leaves and a bud at the base. If you will now carefully 

 remove one of these seedlings from the soil the small root may be 

 seen. Coming from this root are small fibers, the rootlets. At 

 the end of the main root is a small point, the root-cap, free from 

 sand. The root pushes its way through the soil by means of this 

 cap. Growth, however, does not take place at the root-cap, but 

 at a short distance back from the tip. 



2. PKA. In germinating the pea behaves very different from 

 the bean. The first thing observed is the arch, but the two 

 seed-leaves remain in the ground. They do not perform the func- 

 tion of leaves as do the seed-leaves of the bean. ,The little plumule is 

 arched till it is above the surface of the ground, when gradually it 

 straightens out. The arch of the bean and pea protect the deli- 

 cate structure of the plant. In an older pea plant small leaves or 

 scales may be seen at the lower end near the ground. Further up 



the stem the leaves gradually become larger. 

 An examination of an older plant with the 

 seed still attached will show that the sesd- 

 leaves are withered. What has become of 

 this material stored in the fleshy seed-leaves? 

 It has been used as food by the growing 

 plant. You will observe in peas which are 

 beginning to germinate that a slender cylin- 

 drical body is making its way into the soil. 

 This is the primary root. Fig. 21. It is not M g ure 21. 



straight, but curved. If you will watch its' P and pilule at/ radicl " 



