350 THE STRUCTURE OF ECONOMIC PLANTS 



xylem, and it diverges centripetally until it is continuous with the 

 inner face of this band; in other cases, the trace may occupy this 

 final position from the outset. 



cort fv h 



cort fv b 



cort f b M 



cort fv b 



M 

 coHfb M 



coHfb 1-2 



M fv b 



Fig. 177. A-H, diagrams showing vascular transition. A, primary root ; B and C, hypo- 

 cotyl; D, cotyledonary node; E, first internode immediately above divergence of cotyle- 

 dons ; F and G, middle and upper regions of first internode ; H, second node : c-i and c-i, 

 cotyledons ; cort f b l-i, cortical fiber bundle to first leaf; cort / b 1-l, cortical fiber bundle to 

 second leaf; cort fv b, cortical fibrovascular bundle; end, endodermis ; /-i, /-i, vascular 

 strands to first and second leaves ; l-i fv b, fibrovascular bundle of first leaf; mx, metaxylem ; 

 pel, pericycle ; ph, phloem ; ph c-i and ph c-t, phloem to cotyledons ; ph fib, phloem fibers ; 

 ph /-I, phloem to first leaf; pi, pith; pri ph, primary phloem; px, protoxylem ; x c-i and 

 X c-T., xylem to cotyledons ; .v /-i and x /-x, xylem to first and second leaves. QB-H adapted 

 after Compton, Linn. Jour. Bot.') 



