296 



BOTANICAL GAZETTE 



[OCTOBER 



SALIX GLAUCOPHYLLA 



u 



Leaf 



X 



T.... 

 UE.. 

 P.... 

 Sp. . . 

 LE.. 

 OW.. 

 Cu.. 



185 /x (180-208) 



231 /x 



(219-240) 



20 =10 per cent 



19 = 



■ 9 per cent 



92 =50 



120 = 



: 52 



57 = 3* 



60 = 



: 3o 



16 = 8 



19 - 



: 9 



43 



4.8 





1.6 



1.6 





s 



57 



Stem 



X 



64 



45 



47 



2-3 



2-4 



3-i 



4.8 



5 



3-2 



2-4 



4 



<6 



80 



N.. 



D.. 



W.. 



F... 



L... 



R.. 



Cork. 



Collen 4-6 layers 7 layers 



Little variation, but the palisade is In the dune form more vessels and 



slightly deeper in the dune form; the larger; the fibers heavier and the lumina 



vessels of the midrib are larger though smaller, giving more wood; growth rings 



about as numerous, their walls are heavier about the same; more cork, collenchyma, 



as is also the outer epidermal wall, and and sclerenchyma. 

 there is more collenchyma. 



CORNUS STOLONIFERA 



A plant growing on the edge of a river was partly submerged by a dune. The 

 stem was examined to find the difference between the submerged and the aerial parts. 



Submerged 



Cortex and phloem 400 m 



Wood cylinder 836 



Pith i 97 6 



3212 



Aerial 

 380 M 



950 

 1482 



2812 



The upper exposed part is not as large as the submerged part, but the wood 



cylinder is larger. 



N, 



W 

 F. 

 L. 



Submerged 

 ...62 



23 

 2.3 



5-1 



IO.4 



Aerial 

 44 



3-2 

 5-6 

 5.6 



In a given area in the cylinder there are fewer vessels, larger in diameter but less 

 in area, which must be more than compensated for by the size of the whole cylinder. 

 The walls of the vessels and fibers are heavier and the lumina of the fibers smaller, 

 giving more wood. 



SALIX LONGIFOLIA 



Situation the same, but the parts examined were not parts of the same stem, but 



were of the same size. 



N, 



D 



W 



F. 



L. 



Submerged 



42 

 41 



3-2 



3 



7-7 



Aerial 



51 • 

 43 



2.4 



3-2 



6.8 



In aerial stem more and larger vessels, walls slightly thicker, lumina of fibers 

 smaller, giving more wood. 



The swamp forms on the whole show the same variations as the mesophytic 



forms. 



