251 



mesophytic in its anatomical structure. The leaves are cordate, 

 with a hydathode at the apex of each tooth. (Fig. 5 A.\ 



The epidermis of the upper surface consists of cells which 

 have undulating walls and thin (about 2fji) lateral, inner and 



Fig. 6. Saxifraga nivalis. 



A, Epidermis of the upper surface of the leaf. B, The same (transverse section). C, Epider- 

 mis of the lower surface of the leaf. D, The same. E, Spongy parenchyma. (A, U, C, h 



and E, ^-*^ii). 



outer walls. Cuticle very slightly developed. Stomata numerous, 

 and prominent (Fig. 6, A, B). 



The epidermis of the lower surface is almost similar to 

 that of tlie upper; but the cells are a little larger, and the 

 lateral walls are somewhat more undulating. The stomata are 

 precisely similar to those of the upper surface (Fig. 6, 6', D). 



