576 



THE STRUCTURE OF ECONOMIC PLANTS 



open toward the adaxial surface, and the individual bundles are 

 separated from each other by parenchymatous rays of varying 



Fig. 301. Transections of sectors of stems showing: left, feebly vegetative stem; and 

 right, highly vegetative one : ca, cambium ; col, collenchyma ; en, endodermis ; ef, epidermis ; 

 i fcly inner pericycle ; / ph, inner phloem ; pel, outer pericycle ; ph, outer phloem ; pi, pith ; 

 xy I, primary xylem ; xy 2., secondary xylem. (Redrawn from Kraus and Kraybill, Ore. A^r. 

 Exp. St a.') 



