408 



l'lie iioiles of the slem resemlde in slnicture tliose of li. 

 /((ppoH/cKs. Tlie roots no doubt remain a long time within the 

 epidermis of the parent-rliizome ; they showed (hstincliy ph-rome, 

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



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

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

 intermediate; the young plant in tlie flowering stage whicli I 

 investigated had no interfascicular stereom, but a weak filtrons 

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

 the endodermis was lignified. 



Fig. 48. H. PaUasii. 

 A. Transverse section of a node of a stolon ("/i). B. Portion of transverse section'of 

 stolon C'/i). C- Piece of the same ("/ih ep, epidermis; c, calyptra; co, cortex; r, young 

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

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



The leaf is glabrous in R. 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 R. lapponicus (see p. 403); the 

 epidermis also contained chlorophyll and the outer walls of 

 its cells were about Za 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 



