32 



FOUNDATIONS OF BOTANY 



a scale which represents a leaf) appears; and internodes, 

 portions between the leaves./ 



The student should watch the growth of a seedling 

 bean or pea and ascertain by actual measurements whether 

 the internodes lengthen after they have once been formed, 

 and if so, for how long a time the increase continues. 



FIG. 10. FIG. 11. 



FIG. 10. A Turnip Seedling, with the Cotyledons developed into Temporary Leaves. 

 h, root-hairs from the primary root ; b f bare portion of the root, on which no 

 hairs have as yet been produced. 



FIG. 11. Cross-Section of a Koot, a good deal magnified, showing root-hairs attached 

 to particles of soil, and sometimes enwrapping these particles. 



44, The First Leaves. The cotyledons are, as already 

 explained, the first leaves which the seedling possesses, 

 even if a plumule is found well developed in the seed, it 

 was formed after the cotyledons. In those plants which 

 have so much food stored in the cotyledons as to render 

 these unfit ever to become useful foliage leaves, there is 

 little or nothing in the color, shape, or general appearance 



