1012] 



STARR— ANATOMY OF DUNE PLANTS 



281 



T.... 

 UE.. 

 P.... 



Sp. . . 

 LE.. 

 OW.. 



OSTRYA VIRGINIANA 



Leaf 



M 



X 



78 m (66-95) 



110/x (91-125) 



10 =11 per cent 



11 =10 per cent 



3° =38 



43 =39 



32 



45 



6 



11 



!-3 



3-2 



N. 



F... 

 R.. 



Stem 



M 



24 



D ... 48 M (75) 



W... 2.8 



3-3 

 6.7 



3 



C. . . . 29 



X 



59 



26 m (37) 



2-5 



3-9 



5-6 



3-6 



64 



X. — Upper epidermis slightly thicker 



X. — Rings of sclerenchyma in the 



and wall thicker; little variation in the cortex wider and outer layers of the 

 depth of the palisade, but the layer more pith more sclerenchyma tous; in all re- 

 compact; stomata on lower surface only spects, except as to the thickness of the 

 (in M occasionally on the upper). wall of the vessels, agreeing with the 



majority. 



POPULUS BALSAMIFERA 



T... 

 UE. 

 P... 



Sp.. . 

 LE.. 

 OW. . 

 Cu.. 



Leaf 



M 

 257 M (243-272) 



18 = 7 per cent 



96 =37 

 129 



14 

 4-3 



X 



212 M (195-228) 



17 



8 per cent 



94 =44 



89 

 16 



5 

 1.2 



N 33 

 D.. 



W. . 



F... 



J J- . • 



R.. 

 r 



Stem 



M 



2.9 



4.1 

 7.2 



1-2 



64 



90 



X 



46 M (62) 36 M (50) 



2.6 

 3-8 



6.8 



100 

 90 



The only exception found to the general X.— Vessels agreeing with the majority 



fact that dune plants have thicker leaves in total area, but walls slightly thinner, 



epidermi 



walls of fibers also thinner, but lumen 



than mesophy tic. X. _„__ ., 



and palisade relatively deeper; outer wall smaller, so the amount of wood may be 



and cuticle thicker and ridged; more ves- the same; cork only starting to form in 



sels in the midrib, larger; more fibers M. 



about the stele. Both have stomata on 



both surfaces; all side walls of epidermis 



Plane except those of lower surface in M; 



double palisade. 



