466 Wemham, The Systematic Anatomy of the genus Canephora. 



and the ring is encircled by a sheath of wood fibres, from which 

 radial lines invade the xylem. The latter is traversed by meduUary 

 rays rieh in tannin. 



The phloem appears as a continuous layer some two to three 

 cells broad, and is packed with tannin and calcium Oxalate in the 

 form of crystal-sand. 



The intra-xylary grouiid tissue consists of rather large cells 

 of circular section, with one or two sclerenchymatous fibres. This 

 ground tissue is thick-walled for the most part, but a few thin-walled 

 Clements also appear. Tannin and calcium Oxalate are present, 

 the latter in the form of crystal-sand, both loose and in amorphous 

 Clusters. 



Immediately external to the phloem is an unbroken scleren- 

 chymatous sheath, a single layer of small fibres with lumina obliterated 

 as the result of the thickness of the walls. 



The extra-stelar ground tissue is of uniform parenchyma con- 

 sisting of rather small thick-walled cells. There is a good deal of 

 crystal-sand of calcium Oxalate in this tissue, especially in the 

 neighbourhood of the vascular bündle; this displays a strong ten- 

 dency to aggregation into Clusters. Tannin is somewhat scarce 

 except in the ventral sub-epidermal region. 



The epidermis on the ventral side is distinct from that on 

 the dorsal. The former is composed of large cells, elongated 

 perpendicularly to the surface as seen in section, and with thick 

 cuticle. The dorsal epidermis consists of relatively small cells with 

 roughly circular lumina. No hypodermis is differentiated. 



c) Lamina (Fig. 6, b). Like that of the previous species, 

 the leaf is of a distinctly thick type; the nature and arrangement 

 of the tissues is essentially similar, and the parenchyma is thick- 

 walled. Tannin abounds, especially in the palisade tissue, and 

 also in the region underlying the dorsal surface. Calcium Oxalate, 

 in the form of crystal-sand aggregations and minute Clusters, is 

 more abundant than in C. madagascariensis, particularly in the 

 interior of the leaf and in the spongy parenchyma. 



The ventral epidermis consists of conspicuously large cells, 

 Square or, in some cases, elongated radially. The cuticle is not 

 so thick as in C. madagascariensis. The dorsal epidermis is very 

 distinct from the ventral, being composed of smaller, brick-like 

 cells, with relatively thin cuticle. The small guard-cells of the 

 stomata are appreciably sunk; each is associated with a large sub- 

 sidiary cell which, apart from the cuticle, has comparatively thin 

 walls. This type of Stoma is, therefore, very difierent from that 

 found in the last species. 



III. Peduncle. This is essentially similar in anatomical 

 structure to that of C. madagascariensis, with the important ex- 

 ception that the row of fibre-bundles which accompanies the main 

 bündle in the inflorescence-peduncle of that species is absent in 

 C. angusUfolia. 



