470 Wernham, The Systematic Anatomy of the genus Canephora. 



The pliloem is in some parts froin four to six cells broad. 

 A very definite and coutinuous sclerotic sheath surrounds 

 the main bündle; the constitiient fibres are very large, 

 and often radially elongated in transverse 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 surrounds the bündle. The xylem 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 very few 

 fibres in the xylem. 



c) Lamina. The cuticles are remarkably thick, and 

 the inner side of the wall is irregularly wrinklecl 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 bundies runs parallel 

 with oneojf the flat sides of the main bündle, at a short 

 distance from it, in the cortex. 



C. angustifolia I. Stem. Calcium Oxalate is of rare 

 occurrence in the pith, and is not very abundant in the 

 cortex. The primary xylem is associated with lacunae, 

 which may represent degraded parenchymatous tissue. 



IL 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. GoudoUi. I. Stem. The pith is conspicuouslylarger 

 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 stem mostly as small Cluster crystals. 



II. Leaf. a) Petiole. This is roughly circular in 

 transverse 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 



