PSEUDO- SCLEROTIA OE LENTINUS SIMILIS, &C. 
O 
in figures C and D, Plate I., there is a noticeable difference 
between the heart and sap wood when stained with chlor-zinc- 
iodine. The violet colouration occurs here and there in the 
heart wood, but to a much less extent than in the fibres in 
the sap wood. Even in the heart wood, however, the thickness 
of the walls of the fibres is reduced, though to a less degree 
than in the sap wood. 
The conclusion would appear to be justified that the fungus 
has partly destroyed the walls, more in the sap wood than 
in the heart wood, and that the cellulose lining which stains 
violet is due to the action of the fungus and is not a residue 
of the original cellulose lining of the sound fibres. 
In aniline chloride all the walls stain yellow, the colouration 
being most intense in the medullary rays and the vessels. 
There is marked difference, macroscopic ally, between the 
colour of the sap wood and that of the heart wood in the 
pseudo -Sclerotium when stained with aniline chloride, the 
colouration being much more intense in the heart wood. 
With phloroglucin, the vessels and the medullary rays 
stain pink, whether the pseudo-sclerotium is formed from sap 
wood or heart wood. The colouration of the fibres varies. If 
the wood is sap wood, the fibres stain here and there, often 
in short isolated lengths of the wall of a fibre, the remainder 
being unstained ; but in general the fibres do not stain, and 
the contrast between the vessels, medullary rays, and fibres 
is exceptionally well marked. In the heart wood region of 
the same pseudo-sclerotium the fibres in general are stained 
by phloroglucin, but the colouration is paler than in normal 
Hevea wood ; in the thicker walls the colouration is deep rose- 
red along the middle lamella, the next layers being paler, with 
sometimes a very thin colourless layer lining the cell ; the 
thinner walls are uniformly coloured pale pink, often with a 
deep rose-red patch at the junction of the middle lamellæ of 
the walls of adjacent cells, but some may be quite colourless. 
The débris of the wood surrounding the sclerotium consists 
of fragments of the medullary rays and the vessels. In some 
cases the walls of the cells of the medullary rays are reduced 
to the middle lamella only, but the majority retain some of 
the thickening layers, though much reduced, and show the 
