BUD OF EUONYMUS. 



213 



protuberances. These stand in two-membered, alternating whorls, 

 and are therefore decussate, or " opposite decussate," as we are 

 wont to say. Every new pair of leaves starts, after considerable 

 enlargement of the growing apex, in the gaps between the pre- 

 ceding pair of leaves (Fig. 83 A). With suitable magnification, it 



FIG. 83. Apex of the stem of Euonymm japonicus. A, apical view. of the same 

 (x 12). B, apical view of the growing point (x 240). C, median longitudinal 

 section through the apex of the stem (x 28). D, median longitudinal section 

 through the growing apex ( x 240) ; d, dermatogen ; pr, periblein ; pi, plerome ; 

 /, leaf-protuberance ; g, bud-protuberance ; pf, leaf-traces ; pc, procambium 

 ring ; m , pith ; c, cortex. 



is here easy to follow the arrangement of cells at the apex, as is 

 represented in Fig. 83 B. Cross-sections taken close under the 

 apex show us first the differentiation of the procambium,. which 

 will form the vascular bundles. This appears in the section in 

 the form of a rhombic figure, with somewhat projecting and 



