103 



rather leaf bundle is present in the individual foils of the trefoil, the centra^ 

 cylinder^apparently doing duty for the whole three leaves when the leaf bundle is 

 wanting. 



In the sections reproduced, the stele is mostly divided into three bundles, 

 but there appears no well-defined pericycle, such as in C. Muelleri, surrounded by 

 endodermal cells, but instead between the three oil glands and the stele there is 

 a fair amount of sclerenchyma material such as obtains in C. calcarata. 



Where the oil cavities have not come into view, a few endodermal cells 

 are irregularly scattered at the base of the spongy mesophyll, but when a section 

 is taken through the oil cavities it will be noted that some are arranged around 

 these and so form strengthening cells, and others are clustered crescent-shape at 

 the base of the decurrent channel, as we propose to call this space. 



f^-^ 





Figure 52. — Transverse section of branchlet, and deciir- 

 rent leaves cut below the oil cavities. C. 

 verrucosa, x 70. 



Figure 53. — Transverse section through branchlet and 

 decurrent leaves, higher up than Figure 52, 

 and shomng a cross-cut through an oil 

 cavity in each leaf. C. verriicosa, x 70. 



The palisade cells are only developed at the dorsal side of the leaf and 

 cease at the ventral face, which is the transpiratory surface, for there only do the 

 stomata occur, and which like those of C. glauca have similarly developed cuticle 

 projections. The epidermal cells are well developed, and apparently at the expense 

 of the hypodermal, which are quite insignificant. The dorsal surface is sometimes 

 slightly ridged. The secretory cells of the oil cavities are distinctly seen in 

 Figure 53. The spongy mesophyll occupies a rather large proportion of each leaf 

 area. 



Figure 51 is a transverse section through branchlet and decurrent leaves, 

 below mid-distance between the nodes, and showing no oil cavities, as they rarely 

 occur in this part of the leaves. Although a low magnification (95), yet the general 

 structure of the fundamental tissue can be traced. No leaf trace is present in 

 any of the sections, but the transfusion tissue is scattered irregularly amongst 

 the parenchymatous endodermal cells, some of which are empty, whilst others 



