286 



THE PLANT COVERING OF OCRACOKE ISLAND. 



slit-like furrows between each 2 nerves (hence 2 to every ventral 

 furrow), opening into wider air spaces with stomata at each side of 



the bottom. Stomata also oc- 

 cur near the bottom of the ven- 

 tral furrows, but are there less 

 numerous. 



Epidermis: Ventral (fig. 34) 

 with cell walls thinner than on 

 the dorsal surface, many of the 

 cells extended into straight or 

 curved, spreading, unicellular 

 hairs which line the main cav- 

 ity and lateral furrows with 

 a dense cross work, ami are 

 larger, thinner- walled, and 

 more slender than those which 

 occur on the dorsal surface; 

 bulliform cells none. Dorsal 

 (fig. 35) with smaller cells, the 

 outer wall and cuticle so 

 greatly thickened as nearly to 

 equal the cell lumen, the areas l3*ing above the subepidermal strands 

 of stereome having single rows of short cells which alternate with 

 several rows of long ones; many of the epidermal cells extended into 

 short, stout, pointed, thick-walled, unicellular, appressed, prickle- 

 like hairs, which line the furrows. 



Subepidermal stereome: None on the 

 ventral side of the leaf and in the margin; 



Ftg. W.—Muhhubenj/a filipex— transverse section 

 leaf. Scale 75. 



'Fig. M. MuMenbergia filipes— 

 ventral epidermis of leaf. 

 Transverse section, showing 

 the hairs. Beneath the epi- 

 dermis aro layers of colorless 

 parenchyma. Scale (IK). 



Fig. 35.- MuMenbergia filipes — dorsal part 

 of leaf blade. Transverse section show- 

 ing the epidermis (Ep.1, stereome (St.) 

 and rather thick-walled colorless paren- 

 chyma (Pa.1, which borders on the 

 mestome bundle. Scale 400. 



on the dorsal side in the form of tiattened supporting strands 1 

 beneath the mestome bundles, passing gradually into the often 



" Abgeplattete Trager," Schwendener, Median. Princ, p. 40. 



