470 
Wernham, The Systematic Anatomy of the genus Canephora. 
The phloem is in some parts from four to six cells broad. 
A yery definite and continuous sclerotic sheath surronnds 
the main bündle; the constitnent fibres are yery large, 
and often radially elongated in transyerse section. The 
xylem-gap is almost completely blocked by two or three 
of these fibres. 
b) Midrib. The main vascular bündle is shaped like 
the segment of a circle, with flat ventral side. No defi¬ 
nite fibrous sheath surronnds the bündle. The xydem is 
somewhat loose in texture, and the ring is at most only 
three vessels broad; the vessels are relatively large. On 
the ventral side the wood is irregularly arranged, on the 
dorsal side it is disposed radially. There are yery few 
fibres in the xylem. 
c) Lamina. The cnticles are remarkably thick, and 
the inner side of the wall is irregularly wrinkled and 
folded. Calcium oxalate occurs chiefly in the form of 
crystal-sand. The stomata are not at all sunk; each of 
the rather large guard-cells is associated with a rounded 
subsidiary cell with lignified walls. 
III. Peduncle. Arow of fibrous bundles runs parallel 
with oneo]f the flat sides of the main bündle, at a short 
distance from it, in the cortex. 
C. angustifolia I. Stern. Calcium oxalate is of rare 
occurrence in the pith, and is not yery abundant in the 
cortex. The primary xylem is associated with lacunae, 
which may represent degraded parenchymatous tissue. 
II. Leaf. No definite sclerenchymatous sheath sur- 
rounds the main vascular bündle of the petiole, but the 
walls of the ground-parenchyma cells in the neighbour- 
hood of the bündle are thickened and lignified. The wood 
of the main midrib-bundle is about six cells broad. The 
ground-tissue in the midrib is thick-walled throughout. 
In both midrib and lamina the ventral epidermis is rea- 
dily distinguishable from the dorsal, the former consisting 
of relatively large cells of rectangular section, often 
elongated perpendicularly to the leaf-surface, while the 
latter is composed of much smaller cells which appear 
rounded in section. Calcium oxalate appears mostly as 
minute cluster crystals. The guard-cells of the stomata 
are quite small and sunk; each is more or less overarched 
by a large subsidiary cell with lignified walls. 
C. Goudotii. I. Stern. The pith is conspicuously larger 
than that of the other two species, and it is not lacunar. 
The xylem is sharply defined from the pith. Calcium 
oxalate occurs in the stemmostly as small cluster crystals. 
II. Leaf. a) Petiole. This is roughly circular in 
transyerse section; the extremities ofthe median vascular 
bündle are involute. The phloem tends to invade the 
xylem at a few points. There is no fibrous sheath as in 
