ELECTEO-PHYSIOLOGY 



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 lacunae 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, 



FiG.uo.-Lateraiaspectofa cylindrical cells, with hardly 

 any organised contents (Fig. 



, . 



141). " The innermost layer 

 of these cells impinges on the 

 long slender cells which ac- 

 company the fibro - vascular 

 the vascular bundle there are 



leaf of Dioncea, showing the 



venous system. (F. Kurtz.) 



bundles in the petiole. Below 





FIG. 141. T.S. of lamina of Dioncea leaf, parallel with the lateral nerves. (F. Kurtz.) 



2-3 rows of cells resembling those described above, then 34 layers 



