ANATOMY OF THE JULIANIACES. 139 
The epidermis in transverse section consists of quadrate cells, which are more or less 
arched outwards; it bears numerous clothing and glandular hairs, which are, on the whole, 
of the same type as those occurring on the lamina*. The petiole of Orthopterygium, 
however, bears occasional long undulating clothing-hairs with thin walls scattered in 
amongst the numerous typical hairs. The outer part of the cortex is parenchymatous 
and, in the case of Juliania adstringens, includes numerous small resin-canals arranged 
in a more or less irregular row a little way beneath the epidermis; many of these canals 
were still in process of formation and the figures illustrating their development (fig. 2, A, B) 
were drawn from these sections. The young secretory canal consists of a small cavity 
with granular contents; this is formed by the separation of the surrounding thin-walled 
cells, which exhibit a radial arrangement and are somewhat columnar in shape. Sub- 
sequently division-walls parallel to the contour of the cavity appear in this layer of cells, 
so that the cavity is surrounded by two layers of quadrate cells with thin walls. This 
original structure becomes more or less obscured later on, owing to further divisions 
taking place in the cells surrounding the cavity. The absence of such cortical resin- 
canals in the petiole of Orthopterygium may prove to be a point of generic distinction, 
but it may possibly be due to the petiole examined being a young one. It also 
remains to be seen whether cortical canals are found in the petiole of other species of 
Juliania. 
The inner portion of the cortex is formed by several layers of well-differentiated 
collenehyma ; the cells, like those of the outer parenchymatous portion of the cortex, 
have strongly undulated walls, which are generally much contracted. Between the 
collenchyma and the phloem of the vascular bundles a number of layers of much larger 
cells are developed, especially in Juliania adstringens. A small number of clustered 
crystals are generally scattered through the cortex. 
The pith of the petiole is surrounded by a zone of vascular bundles which differ slightly 
among one another in size. Near the base of the petiole these vascular bundles are 
arranged to form an arc-shaped group, the convex surface of the arc being directed 
downwards, whilst the free ends are bent in towards the concave surface; the shape is 
like that of a broadly opened V with the free ends turned inwards. At the upper end 
of the petiole, immediately below the insertion of the first leaflets, we have a ring of 
bundles due to the joining up of the inverted ends of the original are ; the dorsiventrality 
of the vascular structure is, however, indicated by the concavity of the upper portion of 
the ring. The vascular bundles are separated from one another by rather narrow rays 
and, as above mentioned, vary slightly in size; at the upper end of the petiole there is a 
large flat bundle occupying the upper side of the vascular ring. ; 
The vessels forming the xylem of the petiolar bundles have rather wide lumina. In 
the phloem of each bundle a resin-canal is situated, which is of much larger size than 
the cortical canals of Juliania adstringens. These resin-canals of the phloem have a 
large cavity and are surrounded by several layers of thin quadrate cells, the innermost 
* In the case of Juliania adstringens the petiolar glands are much more elongated than those on the Jami 1a, 
The stalk is long and consists of 2 (or sometimes even 3) cells and the glandular head is provided with a considerable 
number of vertical division-walls. 
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