284 



BOTANICAL GAZETTE 



[OCTOBER 



ULMUS AMERICANA 



Leaf 



Stem 



M 

 T 102 /* (94-109) 



X 



174 ix (164-186) 



UE. 



P 



21 

 29 



21 per cent 

 29 



38 



22 per cent 



70 =40 



Sp 38 =37 



51 



29 



ow.. 



Cu. . 



13 = 



3-2 



thin 



13 



15 =9 

 5-2 

 thin 



N 



D 



W 



F. 



L. 



R. 



C. 



M 

 28.5 

 61 /* (104) 



3-7 

 5-9 

 2-9 



66 



X 



52 

 61 



M ( 9 6) 



3-3 



5-7 

 3-7 



5 

 66 



X. — Cells of upper epidermis greater 



Vessels as in majority. X. — Walls of 



in depth; side walls plane, cuticle not vessels and of fibers very slightly thinner 



ridged (in M walls slightly wavy and than in M and lumina of fibers larger, yet 



cuticle slightly ridged on lower surface) ; masses of fibers so much more numerous 



palisade deeper sometimes double, mid- they form more wood; cork and cortical 



rib structure as in other X. In both sclerenchyma the same, 

 upper surface rough, hairy (X more so); 



some epidermal cells enormous. — Figs. 

 18 and 19. 



18 



19 



Figs. 18 and 19. — Ulmus americana: sections of leaves; fig. 18, mesophytic 



form: fie. 10. dune form 



