LABORATORY PRACTICE 



6. This elongated plumule consists of several joints (nodes}, 



each bearing a/<f#/(or scale representing a leaf) and 

 intervals between these (the internodes). 



7. Make a sketch showing these different parts and label 



each carefully. 



V. Take a pot of well-grown Bean Seedlings and notice : 



1. The position of the cotyledons relative to the surface of 



the soil. 



Examine some seedlings which have been carefully 

 removed from the soil and notice that : 



2. The cotyledons have cast off (as a general rule) the seed- 



coats and have separated from one another. In the 

 older seedlings they have become greenish ; and in the 

 oldest seedlings of all they have dried up and fallen off. 



3. The caulicle has elongated to many times its original 



length and has become stouter and green in color. 



4. A stout main root (a primary roof) with branches has 



grown from the tip of the caulicle. 



5. The plumule has lengthened and consists of several 



nodes, internodes, and leaves. 



6. The leaves borne upon the first node above the cotyle- 



dons number two, are on opposite sides of the node, 

 and are different in size, shape, color, and texture from 

 the cotyledons. They are also placed upon the stem 

 at right angles to the cotyledons. 



7. The second node above the cotyledons bears a single 



leaf, having its flattened portion (the blade) in three 

 separate pieces instead of in one as in the cotyledons 

 and the first pair of green leaves. 



8. Make a sketch of the Bean Seedling showing these 



points. 



