KNOWLEDGE OF MONOCOTYLEDONOUS SAPROPHYTES. 189 
{outer) epidermis, and a mesophyll composed of slightly elongated 
parenchymatous cells, amongst which the vascular bundles run. 
Raphide-mucilage cells occur in the mesophyll, and are more 
numerous than in the neighbouring portions of the axis. The 
outer epidermis has thicker, more heavily cuticularized walls than 
has the inner epidermis. Stomata occur in the outer epidermis 
only, being most numerous in the subterranean scales, and 
constantly decreasing in number higher up the axis. Their shapes 
are varied and they remarkably resemble those of Aphyllorchis. 
The vascular bundles run nearer the upper (inner) surface of the 
leaves. When entering the leaves possess tracheides and spiral 
vessels, sieve-tubes, parenchyma-cells. In the finer bundles the 
spiral vessels disappear, and the phloém is represented by a 
mass of parenchyma, but the tracheides increase in number, and 
when the phloém is eompletely lost the bundles consist solely of 
a number of tracheides running immediately within the inner 
epidermis. Thus there is a hypodermal of tracheides like that in 
Galeola. And,just as in Galeola, this system is most extensively 
developed in the subterranean scales and least in the bracts. In 
fact, high up the inflorescence-axis this system is, in parts of 
the leaf, only represented by single tracheides completely isolated 
from the vascular bundles: thus, as in Galeola, some of the 
mesophyll-cells are converted into tracheides. 
It is worthy of note that, going from the rhizome to the top 
of the inflorescence-axis, the scales diminish in size and number, 
the stomata on the scales and axis also decrease in number, the 
hypodermal tracheides of the scales dwindle, the cuticle of the 
axis becomes very much thicker, and the water-conducting 
xylem dwindles. These facts again suggest that the leaves are 
organs by which the plant rids itself of any excess of water. 
Side by side with these histological changes there is a concen- 
tration of mechanical tissue into the general sclerenchyma-sheath, 
which acquires thicker walls, and at the same time a dwindling 
of the cortex outside this sheath. 
In my specimens fungal hyphe had penetrated all the scale- 
leaves vid the inner epidermis. High up the inflorescence-axis 
I saw hyphe running up the xylem, but nowhere else in the 
sections. So I suppose that the hyph could only gain entrance 
by means of the scale-leaves, and, traversing the leaf-bundles, 
they reached the bundles of the axis without being obliged {to 
pieree the apparently impenetrable general sheath. 
