80 STRUCTURAL BOTANY 



placed directly opposite the xylem, but lie rather 

 farther to the right and left, so that in each pair of 

 bundles the two groups of phloem are farther apart 

 from each other than are those of the xylem. Now, 

 the farther we trace the vascular bundles downwards, 



-px.. 



FIG. 31. Part of transverse section of hypocotyl of Wall- 

 flower, showing cylinder, px, px, protoxylem groups of 

 the four bundles from the cotyledons ; x, x, their xylem, 

 ph, ph, their phloem groups. From the middle of the 

 transitional region between stem and root. Magnified 

 220. (E. S.) 



the nearer to each other do we find the xylern groups 

 of each pair, and as they approach each other their 

 protoxylem turns more and more towards the outside 

 (see Fig. 3l,px). Lower down still, we find in place 

 of each $air of xylem groups a single one, with its pro to- 



