OF THE LEAVES OF CERTAIN SPECIES OF VERONICA. 263 
Fig. 18. 
Transverse section of leaf of V. lycopodioides, near the tip. ж 300. 
V. Hectori, Hook. f. *. 
The leaves here are completely appressed to the stem ; they are blunt and 
connate at the base, with a few hairs at the point of junetion. The outer epi- 
dermis has its outer cuticularized walls as thick as the cell-cavities are deep, 
so that the guard-cells of the stomata are deeply sunk beneath the surface of 
the cuticle ; the entrance to the stomatal vestibule is very narrow (fig. 16 a). 
There is a layer of water-tissue along the inner (upper) epidermis ; palisade- 
cells occur along the outside. The bundles lie close to the inner side. The 
leaf-trace passes horizontally through the cortex and bends at right angles on 
entering the leaf (fig. 2. p. 250) ; the dense thickened xylem begins after this 
point. Cork-cells are developed as a narrow band almost at right angles to 
the leaf-trace. 
V. Armstrongii, T. Kirk. 
This is very like V. Hectori, but has thinner branches and the tips of the 
leaves are free. The epidermal walls are less thickened than in the last, but 
* Bot. Mag. t. 7415. 
LINN. JOURN.— BOTANY, VOL. XL. U 
