254 МВ. В. S. ADAMSON ON THE COMPARATIVE ANATOMY 
with occasional cells showing a division. The spongy tissue is formed of 
many-armed cells with considerable interspaces. 
The most striking feature about this species is the knob-like tip to the leaf. 
In this region the epidermis consists of large columnar cells with thickened 
and cuticularized outer walls, which pass gradually into the normal 
epidermis of the leaf. The internal tissue of the knob consists of small- 
celled parenchyma in which the bundle ends ; the tracheal elements persist 
till quite near the tip. Opposite the end of the bundle is a small stoma, so 
that the knob is a peculiarly protected hydathode (fig. 7). 
Cork is not developed at the leaf-base till just before the fall of the leaf. 
RIP | 
a > mh Oy WIAA = 
EN 5998 
ESL AA] [7 
ANNS ады 
15, 
Hydathode at leaf-apex of У. elliptica : t=end tracheids, s = water-pore. 
V. Lewisii, Armst. 
This species is externally very like V. elliptica, but the leaves are narrower 
and larger. А few short hairs occur along the margin. Тһе tip has a quite 
normal hydathode. Stomata occur on both sides. A hypoderm occurs along 
the upper side and is sharply marked off from the mesophyll ; it contains no 
chloroplasts. The differentiation into palisade and spongy tissues is not well 
marked. Cork is developed in large quantity at the leaf-base. 
The next two species, V. parviflora and V. parvifolia, have very long and 
narrow leaves. 
V. parviflora, Vahl, has leaves 2-3inches long. Stiff hairs occur over the 
