OF THE LEAVES OF CERTAIN SPECIES OF VERONICA. 261 
V. subalpina, Cock. 
The leaves are mostly small, glaucous, and quite glabrous, with much 
thickened epidermal cells. The mesophyll consists of rounded cells, which 
are rather smaller towards the lower side. Herbarium material showed 
a tendency towards а hypoderm formation under the upper epidermis. The 
cells here have few chloroplasts and much vacuolated protoplasm ; this is 
quite absent in the cultivated material. Cork is developed very early at the 
leaf-base. 
Fic. 12. 
=F f ` — >=. 0 
ее. 
Г ne 
Transverse section of leaf of V. monticola. a=assimilating cells; w, hypodermic tissue, 
x 200. 
V. monticola, Armst. 
This species shows some marked peculiarities. The leaf is short, lanceolate, 
and soft in texture ; it is furrowed above, with a corresponding keel below. 
The wings are very thick, owing to several layers of large cells between the 
upper epidermis and the main assimilating tissue ; these large cells contain 
