i6x THE STRUCTURE OF ECONOMIC PLANTS 



leaf. These are connected on the scutellar side of the axis with a 

 "common" bundle, that extends through the stem for some dis- 



■ cotyledon 



' = midrib & 2 lateral bundles of 3rd leaf 



, = „ - ^ - . - 2nd • 



> = coleoptile bundles 



coleoptile 



1st leaf above cotyledon 



midrib of 2nd leaf 

 above the cotyledon 



•- - level of divergence of coleoptile 

 - cotyledon 



ventral scale {ligule) 



endarch collateral bundles 



^jprimordia of upper (younger) 

 pair of seminal roots 



^^ ^^y* — H CN> tip of epiblast 



primordium of seminal root 



nodal plate of the cotyledon 



steles of lower (older) pair of 

 seminal roots 



■'-stele of primary root 



Fig. 71. Detailed course of vascular bundles and scattered vascular elements in portion 

 of seedling, upper and lower limits of which are indicated in Fig. 70. (After Boyd and 

 Avery.) 



tance and terminates as a leaf trace or traces. The median lateral 

 bundles of the second leaf are united with adjacent coleoptilar 

 bundles, and the resultant bundles anastomose with the scutellar 



