270 HOW CROPS GROW. 
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 
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, 7. 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 
