75 ° Hems ley . — On the Genus Cory no car pus, Forst., 
beneath the lower epidermis, which shows up in the shape 
of loosely arranged polygonal cells in surface view. The 
palisade tissue consists of two layers of almost isodiametric 
cells, and is not very well differentiated from the loose spongy 
tissue, the cells of which appear more or less transversely 
elongated in a transverse section of the leaf. Altogether the 
spongy tissue occupies about four times as much of the 
diameter of the leaf as the palisade tissue. The vascular 
bundles of the veins are all embedded in the mesophyll (m), 
and the larger ones are accompanied, both above and below, 
by rather wide-lumened sclerenchyma. A characteristic 
feature of the leaf-structure is the abundance of large clustered 
crystals (ccr) ; these occur especially in the two layers of 
nypoderm on the upper side of the leaf and also in the 
hypoderm-like, lowermost cell-layer of the spongy tissue. 
Very frequently also they occur in specially enlarged cells 
of the mesophyll, arranged in an interrupted line in about 
the middle of the leaf. Cork-warts occur in small numbers 
on the lower epidermis. 
Anatomy of the Axis. (Fig. 28.) 
In a transverse section of the stem the primary bundles ( pb ) 
project more or less considerably into the pith ( p ). The 
vessels of the wood are not very abundant and not very 
wide-lumened. The main mass of the wood is made up of 
prosenchyma, part of which is thick-walled and part thin- 
walled (x), the two kinds of cells lying in approximately 
tangential bands. The medullary rays (mr) are rather broad, 
as much as 6-seriate, and their walls are simply pitted. The 
pith consists of large, rounded, thin-walled, non-pitted cells, 
many of which contain large clustered crystals (ccr). The 
pericycle contains isolated groups of rather wide-lumened 
bast-fibres ( bf ), placed opposite the primary bundles. The 
cortex (pr.c) abounds in clustered crystals, and these also occur 
in the secondary bast (s) opposite the medullary rays. The 
cork (c) arises in the second cell-layer beneath the epidermis ; 
the cells are thin-walled, flat or somewhat elongated radially. 
