THE WHITE LILY 165 



round the cylinder. We thus see at once that the 

 structure is essentially the same as in the young root 

 of a Wallflower, but in the Lily there are many 

 bundles of wood and bast, while in the Wallflower 

 there were only two of each. In other words, the 



-pc. 



FIG. 64. Transverse section across the central cylinder and 

 inner layers of cortex of a root of the White Lily, e, 

 endodermis ; pc, pericycle ; ph, a phloem group ; x, a 

 xylera group ; protoxylem at the outer end of each xylem 

 group. Magnified 330. (R. S.) 



root of the Lily is polyarch, that of the Wallflower 

 diarch (cf. Fig. 28, p. 73). 



We notice that here also the smallest vessels lie to 

 the outside of each group of xylem. These are the 

 spiral vessels, which were the first to be formed, 

 so that here, as indeed in all roots, we have 

 external protoxylem. The inner larger vessels, which 



