c, A. BARBER. re 
the cells of the hypoderm remain small and equal-sided to the 
end. The structure and appearance of the hypoderm may 
be studied in Plates II, III, V and, especially, Plate VI, fig. 
1, and Plate VII, fig. 5. 
The Collapsed Layers.—These are simple in structure 
and are formed asin Santalum. They extend upwards, when 
fully developed, to just outside the point where the endoder- 
mis ceases (Plate V, figs. 1 and 2, and Plate VII, fig. 1), thus 
differing totally from those in Olax. In very old haustoria, 
however, they are left far behind by the secondary thickening 
of the xylem and form an insignificant part of the haustorium 
(Plate IX, fig. 5). Their usual downward ending is, as stated, 
peculiar. Instead of passing to near the ends of the cortical 
folds as in Santalum, they end half-way between this point 
and the edge of the host’s wings. It is possible that this posi- 
tion may be partly the result of the secondary thickening 
which so frequently takes place in the end of the fold, but, 
whatever its cause may be, the result is that the collapsed 
layers soon become vertical (Plate V, fig. 2), and, as secondary 
thickening proceeds, ultimately converge downwards (Plate 
IX, figs. 1 and 2). A few cases have been met with in which 
the cortical folds remain long and thin, having no secondary 
thickening. These extend further round the attacked root 
than usual, and their collapsed layers also pass towards the 
ends of the folds. 
The lacunar region inside the collapsed layers is situated 
much lower down than in Santalum and Olax. The tissue within 
the upper parts of the collapsed layers is free from breaks, but, 
outside the cortical wings of the host, the cells are crushed and 
separated by a series of characteristic lacune (Plates V and V1), 
The collapsed layers first appear in the cortex between 
the starch-laden cells and the larger, empty cells without. 
They are formed, as in Olax and Santalum, from the decay of 
masses of crushed cells in the cortex. In Cansjera all the 
additions appear to be from the inner sides. The cortical cells 
on the outer side thus usually retain their form and are not 
