ELECTRO-PHYSIOLOGY 



CHAP. 



leaf (Fig. 140). The parenchyma of the lobe is entirely com- 

 posed of elongated or oblong 

 cells, their long axis being 

 parallel with the main bundles 

 of the lateral veins, and ver- 

 tical to the mid-rib (Fig. 141), 

 while they are circular (in 

 the long section of the leaf) 

 in cross-section. Large in- 

 tercellular lacunre appear be- 

 tween the single cells. 



Below the epidermis of 

 the upper surface of the leaf, 

 the oblong hexagonal cells of 

 which are rich in starch, lies 

 a layer of somewhat shorter 

 thin-walled cells, succeeded 

 by 23 layers of larger, longer, 



Fio.i4o.-Lateraiasi.ect of a cylindrical cells, with hardly 

 leaf of Diona, showing the any organised contents (Fig. 



141). " The innermost layer 

 of these cells impinges on the 

 long slender cells which ac- 

 company the fibro- vascular 

 bundles in the petiole. Below the vascular bundle there are 



venous system. (F. Kurtz 



FIG. 141. T.S. of lamina of Dininrn lr,-ii', parallel with the lateral nerves. (F. Kurt/.) 



2-3 rows of cells resembling those described above, then 3-4 layers 



