408 



The nodes of the stem resemble in structure those of B. 

 lapponicus. The roots no doubt remain a long time within the 

 epidermis of the parent-rhizome ; they showed distinctly plerome, 

 periblem and dermocalyptrogen. (Fig. 48, A). 



R. PaUasii and B. lapponicus differ in the structure of 

 their peduncles (see Fig. 43); also in this point the hybrid is 

 intermediate ; the young plant in the flowering stage which I 

 investigated had no interfascicular stereom, but a weak fibrous 

 tissue outside the leptome ; upon the inner side of the bundles 

 the endodermis was lienified. 



Fig. 48. В.. PaUasii. 



A. Transverse section of a node of a stolon (^"/i). Б. Portion of transverse section of 

 stolon C"/i)- C- Piece of the same {"ii); cp. epidermis; c, calyptra; со, cortex; r, young 

 root; pb, periblem; pi, plerome; ph, leptome; x, xylem; I, lacuna; p, non-lignified paren- 

 chyma; 6, collapsed tissue; mh, pith-cavity. 



The leaf is glabrous in B. PaUasii and somewhat fleshy; 

 the thickness varied between 340 and 510//. It has brown 

 spots especially upon the upper surface, as the epidermal cells 

 probably contain tannin as in B. lapponicus (see p. 403); the 

 epidermis also contained chlorophyll and the outer walls of 

 its cells were about Ъ ц thick; the radial walls were somewhat 

 undulating, almost equally upon both surfaces. The stomata 

 were on a level with the surface or projected slightly, about 



