160 BOTANICAL GAZETTE [MARCH 
with two slightly convex and two concave faces; pluricellular but 
relatively short hairs are to be observed along the angles. The cuticle 
is quite thick and shows longitudinal striations. The epidermis con- 
sists of rather large cells, with the outer wall somewhat thickened; 
there are several stomata of the same structure as those of the leaf, 
but the lateral walls of the subsidiary cells are straight, not undulate. 
Several of the epidermal cells contain large druids. 
There is no collenchyma and no stereome, the cortex thus forming 
an uninterrupted cylinder around the stele. The cortex consists of six 
layers in the angles, and of four between them; it is a very thin-walled 
parenchyma of quite large cells with wide intercellular spaces. It 
contains chlorophyll, raphides, and druids of calcium oxalate. An 
endodermis of small, thin-walled cells, with the Casparyan spots very 
distinct, surrounds the stele of collateral mestome strands. In these 
the leptome forms an almost confluent zone, while narrow rays of 
parenchyma (one or two rows) separate the short hadromatic rays 
with only two or three vessels in each row. The greater portion of 
the central cylinder is occupied by the pith, which is thin-walled but 
solid, and in which druids are frequent. 
Druids were thus observed in the parenchyma tissues as well as 
in the epidermis, and they are very conspicuous on account of their 
unusually large size. 
The leaf.—The structure is bifacial, with the stomata confined 
to the lower face, and with the chlorenchyma differentiated into a 
typical pneumatic and a palisade tissue. 
The cuticle is thin and smooth except where it covers the hairs 
and the midvein of the lower surface of the blade, where it shows a 
distinct wrinkling longitudinally. Viewed en face the lateral cell 
walls of the epidermis are undulate on both faces, and the stomata 
have two subsidiary cells, the lateral walls of which are frequently 
undulate like the others. Hairs are frequent above and below the 
larger veins; they are pluricellular, with mostly four cells in one 
row and the apical one pointed; the cell walls are rather thin. 
Along the margins of the blade the hairs are more frequent, but 
much shorter, consisting of only one or two cells. Viewed in trans- 
verse section, the leaf is perfectly smooth on the upper face, but on 
the lower the midrib forms an obtuse keel. The epidermis is thin- 
