412 
Petch . — Mocharas and the Genus Haematomyces. 
starch for amyloid) grains, from half a dozen to over fifty, usually in a group 
towards one side of the cell. As a rule the cells are free from one another, 
but sometimes a few may be united in pairs. They are bound together 
by a comparatively small quantity of a finely granular slime. The external 
covering consists merely of an outer layer of the same cells, browned, 
collapsed, and glued together by the hardened slime : it may attain a 
thickness of ioo /x. 
If the cortex from which Mocharas is issuing is stripped off the wood, 
a thin layer of the same substance is usually found lying between the two. 
This layer is not continuous, but is interrupted by small islands of tissue 
from one to five millimetres in diameter, or sometimes by large continuous 
sheets. There are also other smaller masses of tissue, projecting from the 
surface of the wood, or the inner surface 
of the cortex, but lying beneath the slimy 
layer. These patches are usually more 
numerous on the cortex than on the wood. 
On exposure the slime rapidly turns 
brown. 
On cutting out a piece of the cortex, 
with the underlying wood still attached, 
the following conditions are found : Im- 
mediately external to the wood is a layer 
of parenchyma, consisting of rectangular 
cells arranged regularly in radial rows. 
This layer may be 2 mm. thick. The 
cells do not contain any of the sphaero- 
crystals which are a prominent feature of 
normal Bombax cortex, and the layer 
lacks the lignified fibres which occur so 
abundantly in the outer normal tissue. 
Instead of the latter, there are usually two, sometimes three, longitudinal 
bundles of lignified vessels, often running somewhat irregularly, with 
scalariform thickenings. These vessels, like the normal Bombax cortical 
fibres and stone cells, give the usual lignin reaction with phloroglucin. 
They may run singly through the parenchyma, or be united in bundles 
of two or three. Sometimes they bear a slight resemblance to the vessels 
of the Bombax wood, though much smaller in diameter, but as a rule they 
are distinctly scalariform. The walls of this parenchyma do not stain with 
Sudan glycerine : a number of globules in the cells take the stain, but 
this occurs also in normal cortex. The walls are stained yellow-brown by 
chlor-zinc-iodide : they do not stain with phloroglucin. 
No layer corresponding to this is found in normal Bombax cortex. In 
the latter, the cortex consists chiefly of rows of lignified fibres, with narrow 
Fig. i. Inner surface of the cortex 
of Bombax malabaricum , when producing 
Mocharas. The white areas are unaltered 
cortical tissue ; the intervening shaded 
spaces are the galleries. Natural size. 
