Bowenia spectabilis , Hook. f. 485 
divided up into narrow radial bands separated by medullary 
rays of equal width (Fig. 15, xy. 2 ). The protophloem forms 
a wide band of crushed tissue (Fig. 15,/.//^) : the secondary 
phloem contains no fibrous elements such as are so abundant 
in the phloem of the root. 
In the upper portion of the stem the orientation of the 
bundle is by no means constant, and occasionally bundles 
are found whose orientation is inverted. 
The stem is surrounded by a layer of cork continuous with 
the pericyclic periderm of the root. The cells of the phello- 
derm contain numerous cluster-crystals of calcium oxalate. 
The cells of the ground-tissue have undergone a considerable 
amount of primary division. Many large mucilage-canals 
traverse the stem in an obliquely longitudinal direction in 
the neighbourhood of the vascular bundles, though it is not 
easy to trace any constant relation between the direction 
of the canal and that of the bundle. The canals are not 
continued into the root : branches are given off which pass 
into the leaves, but they are not found in the cotyledons. 
A large mucilage-cavity is found near the stem-apex, with 
which the canals communicate. 
The Leaf. 
The leaf consists of a swollen leaf-base, a long petiole, and 
a bipinnate lamina (Fig. 1). The young leaf has well-marked 
circinate vernation : its younger portion is protected by brown 
uniseriate hairs, each of which consists of a short basal cell 
upon which is inserted a long terminal cell. 
The leaf-base is crescent-shaped in transverse section (Fig. 
16). The edges of the base of the youngest leaf fold round, 
and enclose the growing-point of the stem. A peripheral 
band of cork is formed in the ground-tissue (Fig. 16 c.). The 
vascular bundles are orientated normally, the xylem being on 
the ventral side. In structure the bundle of the leaf-base is 
similar to that of the leaf-trace in the stem (Fig. 15), except 
that a few elements of centripetal wood, which become more 
