Wernham. The Systematic Anatomy of the genus Canephora. 
461 
The phloein is of one or two layers only. These are densely 
packed with tannin and calcium oxalate chiefly in the form of 
crystal-sand. The phloem apparently surrounds the wood-cylinder 
almost completely. The intra-xylary tissue consists for the most 
part of cells with very thick walls, among which groups of thin- 
walled cells are interspersed, as in the stem. A certain amount 
of tannin and crystal-sand of calcium oxalate occurs in this tissue. 
There is no continuous fibrons sheath in the midrib as in the 
stem and petiole. A few fibres appear here and there, associated 
with the main bündle, principally on the ventral side where they 
form a broken seiies. 
The extra-stelar gvonnd tissne is of more or less large paren- 
chymatous cells, many with relatively thin walls. A number of 
thick-walled elements also appear, especially in the neighbonrhood 
Fig. 5, c. 
Fig. 5. Diagrams of leaf-midrib in (a) Canephora madagascariensis, 
(b) C. angustifolia, ( c ) C. Goudotii, in transverse section. 
V. r. ventral rib; d. r. dorsal rib; other signs as in Fig. 3. 
of the bündle, where they doubtless take the place of a more 
definite fibrous sheath; the latter we shall meet in the case of the 
other two species. No definite sclerenchymatous fibrous tissne is 
present in the ground tissue. Tannin is abundant in this ground 
tissue, especially in the ventral rib. Crystal-sand of calcium oxa¬ 
late, more or less loosely aggregated, is fairly plentiful. 
The epidermis on both sides is similar to that of the stem, 
but the cuticle is even thicker. 
c) Lamina. (Fig. 6, a.) The leaf is relatively thick. The 
palisade is clearly differentiated from the “spongy“ tissue, but the 
lacunar sj^stem in the latter is but feebly developed. 
A single row of fibre-bundles appears at frequent intervals 
in transverse section running in different directions in the interior 
