IN CEYLON. 
49 
substances are not abundant. The central timber will tend to 
become dark in colour when the communication between the 
elements is not frequent, as the substances must then remain 
in approximately the same area in which they were formed. 
The jet black colour of the timber of species such as D. 
Ebenum is due to the coloured substances being present in 
large quantities in the oldest wood and remaining approxi¬ 
mately in that area. If a more open communication existed 
between the elements in this species the colouring materials 
would be more widely distributed and the central timber 
deteriorate in consequence. 
The red, yellow, or white colour of many Diospyros 
timbers is due either to the more complete distribution of the 
colouring substances throughout the wood in the respective 
species or to the relative scarcity of coloured substances. 
The climate does not appear to have any appreciable 
influence on the production of discoloured heartwood, the 
same species showing similar characters in the dry, wet, and 
intermediate zones of Ceylon. The majority of our ebony 
is obtained from the dry zones in the northern part of 
Ceylon, because D. Ebenum grows more luxuriantly there 
than elsewhere, and not because the black timber of this 
species is more abundant, per tree, or of better quality than 
that from the scattered trees of the wet zone. 
It is, however, generally believed by Ceylon foresters 
that the nature of the soil exerts some influence on the 
proportion of discoloured wood. Many cases have occurred 
where the trees growing on rocky hill banks possessed 
large quantities of black heartwood, and the proportion of 
ebony decreased as one got on to better soil. According to 
Broun the best ebony in Ceylon is found on rocky well- 
drained soil. It grows well on soils containing a large quan¬ 
tity of clay and on sandy loam with a good subsoil drainage. 
The general belief is that the proportion of discoloured 
heartwood tends to increase in trees grown on poor rocky 
soil. This is substantiated by every forester I have met. 
8(1)4 (7) 
