270 HOW CROPS GKOW. 



magnified sections of a Vascular Bundle or fiber from the 

 maize-stalk. As before remarked, the stem is composed 

 of a ground- work of delicate cell-tissue, in which bundles 

 of vascular tissue are distributed. Fig. 48 represents a 

 cross section of one of these bundles, c, g, A, as well as 



Fig. 48. 



of a portion of the surrounding cell-tissue, a, a. The 

 latter consists of quite large cells, which, being but loosely 

 packed together, have between them considerable inter- 

 cellular spaces, i. The vascular bundle itself is composed 

 externally of narrow, thick-walled cells, of which those 

 nearest the exterior of the stem, A, are termed bast-cells, 

 as they correspond in character and position to the cells 



