Betts. — Aut ecology of Plants of Peridotite Belt, Nelson. 279 



and have thickened walls, and are level with the surface of the leaf ; there 

 are guard-cell ridges. :T^ -^ 



The lower epidermis is the same as the upper, except that the cells are 

 somewhat smaller. There is a thin cuticle on this surface also, i The 

 hairs are not nearly as numerous as on the upper surface. 



Fio. 2. — Myosotis Monroi. Transverse section of stem(x 175). 

 a, unicellular hair ; 6, chlorenchyma ; c, aqueous tissue ; 

 d, phloem ; e, xylem ; /, pith. 



The chlorenchyma is differentiated into paHsade and spongy tissue. 

 The palisade tissue consists of 4 rows of cells — the 3 outer layers are of 

 oval cells, while the 4th consists of cells which are more or less rounded 

 in transverse section. These cells contain numerous large chloroplasts, 

 and there are air-spaces between the cells. 



