392 



THE ANATOMY OF WOODY PLANTS 



mass of storage parenchyma, as is the case in the region shown 

 in Fig. 2700. Vertical tangential sections make the situation 

 more apparent. Fig. 27 la shows a plane of section near the surface 

 of the cylinder. The leaf trace (seen as a dark mass) is completely 

 surrounded by storage parenchyma, which, however, is less well 

 developed below than on the upper side of the strand. It is 

 particularly obvious in this plane that the trace runs in a mass of 



storage parenchyma 

 precisely as in Leea, 

 described above. The 

 tangential sections 

 taken nearer the cen- 

 ter of the cylinder 

 present a very differ- 

 ent appearance. In 

 this region the trace 

 will still be pursuing 

 its vertical course in 

 the stem and as a 

 consequence will be 

 flanked by storage 

 parenchyma laterally. 

 Above the trace lies 

 the parenchyma of 



the foliar gap. This statement may be verified by reference to 

 Fig. 2716. The trace distinctly contains numerous primitive rays, 

 conspicuously absent in the segments on either side, the segment 

 on the right showing the presence of some vasicentric paren- 

 chyma, such as is characteristic of the Vitaceae in general. It 

 will now be convenient to consider the topography of the foliar 

 trace in its relation to the woody cylinder of the stem in a 

 slender upper node of the vine. Fig. 272 reproduces the general 

 relations exhibited by such a thin axis. Obviously, as the cyl- 

 inder of the wood becomes more attenuated, the trace of the leaf 

 will increase in size relatively to surrounding parts. This situa- 

 tion is clearly shown in the illustration, which represents a plane 

 of section immediately below the node and corresponding in 



FIG. 269. Transverse section of the node of the 

 Concord grape. Explanation in the text. 



