52 



The Waterlilies. 





gives off a strong branch to either side. Each branch passes about 45 

 degrees around the stem and then runs obliquely into the vascular cylin- 

 der. Meanwhile each has been joined near the middle of its course by 

 a postero-lateral bundle from the petiole, which, on first entering the 

 stem, bent sharply away from the other bundles and ran along horizontally 

 in the exo-cortex to the corner of the leaf-area before turning inward. 

 The whole is made reasonably clear by a glance at Fig. 22, (a), (c). 



A very similar arrangement of bundles was found at the node of 

 a stolon of N. rubra. It is usual in the Lotos group to find a slender 



leaf a short distance below the young plant near the 

 apex of the stolons. This is the only place in any 

 Nymphaea, I believe, where a leaf can be found at 

 sufficient distance from others to admit of simplicity 

 in the arrangement of the bundles. At some distance 

 below the leaf in question there are four bundles 

 (steles of Gwynne-Vaughan) passing longitudinally 

 in the stolon. Nearer the leaf one of these forks, 

 making five bundles, nearly equidistant from one 

 another (Fig. 23, upper end). Opposite the leaf- 

 base, the bundle on that side of the stolon divides 

 into two parts which run almost in contact through 

 A single root is present here, and its 

 The lower end is toward apical trace, r, passes obliquely inward toward the space 



region of stolon. , . -_ ,. . . 



between the recently split bundle, and part joins 

 each half. Three bundles enter the stolon from the leaf, a central, c, and 

 two lateral, b, e. The central bundle passes in parallel to the root- 

 trace, and a part joins each half of the split stem-bundle. Midway of 

 its course inward, however, it gives off a large branch right and left 

 and these join the next nearest stem-bundles on either side. Each 

 lateral leaf-trace is joined by another small bundle (probably stipular) 

 just within the stem tissues, and the two unite with the right and the 

 left branches respectively of the central bundle. Above this leaf 

 (below, in Fig. 23) the two parts of the split bundle move farther apart, 

 and finally they fuse successively, each with its nearest neighbor, giving 

 rise to five and then the original four bundles of the stolon. Shortly, 

 however, these fused bundles again divide in making ready for the 

 insertion of the next two leaves. The bundles from these leaves are in 

 number and mutual relations identical with those of the first leaf; but the 

 leaves here become crowded and the details of the course of the bundles 



Fig. 28. Vascular system of 

 stolon of N. rubra ? at a node ; 

 b, e, lateral leaf traces ; <s, cen- f-Vio node 

 tral leaf trace; r, root bundle. 



