56 TIMBER AND SOME OF ITS DISEASES. [CHAP. 



All have a dense red, brown, purple, or 

 black heart (75 to Ss lbs. the cubic foot) : 

 e.g, Mesua ferrea^ Heriiiera littoralis^ 

 Xylia dolabriformts, Hardwickia 

 binata^ Terminalia to?nentosa, Dyos- 

 pyros Melanoxylofi, &c. These are 

 the chief hard woods of India. 

 y The following (and others) are less easily 

 classified, and other characters have to be 

 used in grouping them : 

 e.g, Dalbergia Szssoo, D. latifolia^ Bassia 

 latifoUay Melia indica^ Acacia 

 arabzca, A, catechu, Lagerstroemia 

 parviflora^ Pterocarpus Marsupium^ 

 &c. 

 (2) No such partial zones or "false rings" are evident; 

 the wood is practically devoid of annual rings 

 (though microscopic examination of thin sections 

 may show traces). 

 (1) Soft wood ; no heart-wood formed ; grey (Bombax 

 type) : 



eg. Bombax malabaricmn, Mango, 

 (ii) Heart- wood usually present, and the woods denser 

 and less porous : 



eg. Albizzia Lebbek, Schima Waiitchii, 

 ZizyphusJitjuba^Tamarixarticulata^ 

 Adina cordifolia, Diptero carpus 

 tubercidatus, &c. 



B. Dicotyledons in which the annual rings are always dis- 

 tinguishable, and usually obvious, though they may be very 

 narrow. These rings are marked in two chief ways, and a 

 little practice enables the student to distinguish them easily 

 in most cases. 



(a) The annual rings are particularly clear, because the 

 vessels in the spring wood are either larger than 



