12 STUDIES IN ROOT-PARASITISM. 
tissues will be noted and a summary statement prepared of 
the characteristic features of the haustoria as contrasted with 
those of Santalum and Olaz. 
TISSUES OF THE MATURE HAUSTORIUM. 
9. Cork and Lenticels.—Cork is very common in Cans- 
jera haustoria, much more so than in Santalum, but its pres- 
ence does not discolour the surface of the root as it does in 
that plant. The cork in Cansjera is whitish yellow, and this 
is the prevailing colour of both its young and old haustoria. 
It will be remembered that in Santalum the cork forms a bright 
red-brown layer and that the older roots as well as the 
haustoria assume this colour, 
In Cansjera Rheedii, cork is frequently continued round 
the cortical folds as far as the top of the wings of the host’s 
bark. In one haustorium fixed on a root of Cansjera itself 
very thick layers have been formed both by the host and 
parasite. In the sections of this haustorium the cork is seen 
by transmitted light to be of a dark colour, while the phellogen 
is seen on each side as a thin white band (Plate XI, fig. 3). 
Lenticels are common in Cansjera haustoria, and it is 
doubtless due to them that the haustoria have so irregular and 
warty a surface (Plate IX, fig. 1, lent.). 
Hypoderm.—This, as has been noted, is usually to be 
found in Cansjera haustoria, although it is more distinct in 
some than in others. It consists of a layer of parenchymatous 
cells, within the cork, whose contents are peculiar. Starch 
erains are not found in any great abundance and, when formed, 
are hidden by the granular contents. The latter persist even 
in old specimens and are distinguished by their tendency to 
assume the form of drops. The hypodermal layer is distin- 
suishable by means of this feature after all the rest of the tissues 
are emptied of their contents. The shape and size of the 
cells are also different from those within, for, while the latter 
become extended with the increase in size of the haustorium, 
