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 I). 

 Ebenuin 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 I). 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) 



