6o6 



THE STRUCTURE OF ECONOMIC PLANTS 



The Epicotyl. — At the time of germination, the epicotyl con- 

 sists of a small growing point covered by the primordium of the 



con ph 



Fig. 315. A, transection in upper transition region showing two bundles formed by- 

 branching of one transition bundle. The bundle at right is essentially endarch, but protoxy- 

 lem of other bundle is at one side ; B, transection a short distance above transition showing 

 bundle with connecting phloem strands and absence of inner cambium : ca, cambium ; co, cor- 

 tex; w« />A, connective phloem ; e«, endodermis ; //)/), inner phloem ; w />>&, metaphloem ; mx, 

 metaxylem; /»<:/, pericycle ; />/, pith; /^Z-A, protophloem ; /)a-, protoxylem. (After Rutledge.) 



