certain Species of the Genus Christisonia. 105 
C. subacaulis , Gardn., which it more nearly resembles than 
C. neilgherrica , Gardn. It is, however, of a more typical 
and normal structure than the former species, and for this 
reason I have chosen to describe it first. 
The roots anastomose together to form a complex system, 
but in a less striking degree in this plant than in C. subacaulis , 
Gardn. The tubers, so characteristic of the latter plant, are 
absent in this species. 
The roots may be described as long, wiry, rhizome-like 
organs, of small diameter, which send out at frequent intervals 
on the surface round, knob-like structures. These are the 
young stems. The roots branch freely and grow rapidly in 
all directions in the substratum. 
Ail atomy of the Root. 
In a transverse section of the root (Fig. 4 b) the outer layer 
of cells is seen to consist of small elements with thick outer 
walls, usually of a brownish colour, with granular matter, 
probably soil, attached to them. 
The cortex is built up of rather large cells, which in the 
outer portion are compactly arranged ; the inner portion of 
the cortex consists of much looser tissue, the rounded cells 
exhibiting very numerous intercellular spaces. Nearly all the 
cells of this region have their walls extremely thickened or 
mucilaginously swollen where they border on an intercellular 
space, although the thickening may sometimes occur on 
opposite sides of the common wall of two cells (Fig. 4 b). 
These thickenings were found to stain with methylene-blue, 
Hoffmann’s blue, and aniline violet ; they are more or less 
half-moon or crescent-shaped, with a very convex surface 
towards the cell-cavity. The mycelium of a fungus was seen 
to occur occasionally in the cortex. The cells are often full 
of starch-grains. 
Closely surrounding the central cylinder is a zone, one to 
three layers thick, of small stone-cells , of which some are con- 
siderably larger than the rest ; the root, however, exhibits 
some variation in the number of these elements in this region. 
