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 2/^) lateral, inner and 



Fig. 6. Saxifraga nivalis. 

 Å, 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, li, C, l) 



and E, 262/i). 



outer walls. Cuticle very slightly developed. Stomata numerous, 

 and prominent (Fig. 6, -4, B]. 



The epidermis of the lower surface is almost similar to 

 that of the 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, C, D). 



