Wernham, The Systematic Anatomy of the genus Canephora. 
457 
At more or less frequent intervals, associated with the primary 
xylem, are patches of parenchymatous tissue (xy. p.), consisting 
of small thin-walled cells of polygonal outline. This may represent 
xylem parendrpoa, but in the absence of developmental details 
no definite assertion can be made. There are no medullary rays, 
but the wood is interrupted at frequent intervals by rays of fibres, 
sometimes as mueh as three cells wide as seen in transverse 
section. 
The phloem, which is too perished to be inyestigated with 
much profit, takes the form of a narrow band surrounding the 
Fig. 3, c. 
Fig. 3. Diagrams of the petioles of ( a ) Canephora madagaseariensis, 
( b) C. angustifolia, (c) C. Ooudotii, in transverse section. 
xy. Xylem, lined; ph. phloem, dotted; sc. fibres, small circles; ground parenchyma left 
blank; l.b. lateral vascular Strands; for f. see text and Fig. 4. 
xylem; the cell-walls are thin, and tannin is abundant. Calcium 
oxalate, in the form of crystal sand, occurs but is relatively rare 
in the phloem. 
Immediately externa! to the phloem in transverse section 
appears an unbroken sheath (sh .), one to two cells broad, of rather 
small sclerenchymatous fibres, with very thick walls and lumina 
almost obliterated. 
The cortex consists of large round cells, as seen in transverse 
section, with relatively thin walls. Tannin is abundant, especially 
