THE STEM AND ITS FUNCTIONS 



103 



Fig. 55. Fig. :>ii. 



Fig. 55. — The stem of an herbaceous plant (Digitalis). Transverse section. 

 In this type of herbaceous stem, the fibro-vascular cylinder is thin but unbroken. 



Fig. 56. — The stem of an herbaceous plant {Delphinium). Transverse 

 section. In this type of herbaceous stem, the fibro-vascular cylinder is broken 

 into a ring of fibro-vascular bundles, each containing a group of wood-cells and a 

 group of bast-cells. 



Fig. 57. — The stem of a monocotyledonous plant (Corn). Transverse section, 

 showing the fibro-vascular bundles scattered in the pith. 



