OF THE LEAVES OF CERTAIN SPECIES OF VERONICA, 251 
is thicker, with the stomata on the under side sunk. The spongy cells are 
elongated, but are separated by larger interspaces than occur between the 
palisade cells. Both V. anomala and V. vernicosa have a small hydathode of 
the normal type at the tip of the leaf, at the ending of the central bundle. 
V. Traversii, Hook. f. *. 
The leaves are larger, 1 in. by $ in., the lamina glabrous and slightly con- 
cave above. The stomata are much protected (fig. 165). The greater part 
of the mesophyll consists of elongated palisade-like cells with only a few 
rounded ones towards the lower side. The central bundle is vertically trans- 
current ; the terminal hydathode is very small. Huchedé f describes and 
Fra. 9. 
Tissue of leaf of V. Traversu. х 200. 
figures a hypodermal layer with rather thick walls along the upper side of 
the leaf. My material does not show this except in immediate association 
with the central bundle, and the same is the case with some native-grown 
material obtained from the Cambridge University Herbarium by the kindness 
of Dr. C. E. Moss, and also with material collected by Cockayne from the 
herbarium of the Royal Botanic Gardens, Edinburgh. Leaves from both 
these sources show the same structure as the fresh cultivated material 
examined. 
* Bot. Mag. t. 6390, t Huchedé, 1907. 
