Petch. — Mocharas and the Genus Haematomyces. 41 1 
separate into thin sheets. When a piece of cortex is cut out, it may split 
off along one of the inner layers, and unless the exposed tissue is examined 
microscopically, one is very apt to mistake the smooth, white, cortical layer 
for the surface of the wood. It appears to be essential for the formation 
of Mocharas that the wound, on a living tree, should extend to the 
cambium. 
The following observations were made at Peradeniya on the foregoing 
point, during October, 1918 : 
A rectangular piece of cortex, about 6 cm. by 4 cm., was cut out, down 
the wood, from the stem of a young tree about 30 cm. in girth. The cortex 
was 6 mm. thick. No Mocharas was formed. 
Fourteen young stems, of about the same girth as the last, were 
pollarded at a height of about 4 feet. In one case, a small quantity of 
Mocharas emerged, about six weeks afterwards, at one point on the cut 
surface, from between the wood arid the cortex. In another, the pollarded 
stem produced new shoots near the apex, one of which was wrenched off 
later, and a small quantity of Mocharas was subsequently produced where 
the young shoot had been torn off. 
A piece of cortex, about 5 cm. square, was cut out of the stem of 
a well-grown tree at a height of 4 feet, the girth of the tree at that 
height being i<x\ feet. The thickness of the cortex was 35 mm. About 
three weeks afterwards, Mocharas emerged in small quantity from the line 
of the cambium, the total amount not exceeding a cubic centimetre. It 
issued chiefly along the lower edge of the opening. 
Mocharas. therefore, can be obtained by wounding standing trees, but 
the quantity is very small in comparison with the amount which issues 
from fallen branches or felled logs. 
The Structure, etc., of Mocharas. 
At Peradeniya, Mocharas occurs on sound branches which have been 
broken off by the wind, or on felled Bombax, in either case after they have 
been lying on the ground for a few weeks. It issues as a yellowish- white 
pasty mass, soft and only slightly viscid. The surface soon becomes yellow 
and forms a thin, polished skin, while the inner part remains, for some time, 
whitish, subtranslucent, and soft. If it is broken, the inner tissue rapidly 
turns brown. Finally, it dries &nd hardens, becoming red-brown to purple- 
brown : sometimes the outer skin collapses and the mass becomes irregu- 
larly folded, but in other cases it retains its shape and becomes hollow 
internally. 
When examined in an early stage, the soft, internal tissue is found 
to be composed of large cells, either spherical, 40-90 fx in diameter, or more 
generally oval, up to 130x100 n . These are thin walled and readily 
collapse. Each of them contains a varying number of small, subangular, 
