1 82 



ing lens for their observation, as in Pines, Ebony, Horse chestnut. 

 Willows, etc.... or broad as in Oaks, and Casurina. The breadth of 

 these rays varies from '005 to I. m. m. and we may speak of fine, 

 medium, broad, in classification. In Oaks there are two kinds of 

 rays, large, broad, obvious, with more numerous and finer ones 

 between. In the Beech the broad medullary rays widen out where 

 they cross the boundary between the annual rings, and in some 

 cases so called broad rays are really composed of several, running 

 close together 



6. Next we come to annual rings. It may be questioned whe- 

 ther zones indicating periodic changes in growth are ever entirely 

 absent from timber, but it is certain that in some tropical ever- 

 green trees no such rings can be detected by the unaided eye, or 

 even with a lens. Such timbers are said to be devoid of annual 

 rings, or so called annual rings, as it is not certain that the periodic 

 zones in all cases correspond to the annual increment. 



The following show no annual rings... Iron woods as Mesua fer- 

 rea (Matopus, Penaga puteh), Xylia, Mango, Ebony, and doubtless 

 many of the timbers of the Malay States, but the vast majority 

 shew more or less concentric zones or rings, in many cases obvi- 

 ously annual ones, as in Teak, Cedrela toona, Oaks, etc. In other 

 cases, as Ficus elastica (Rambong) Casurina, (Poko Ru) and Ponga- 

 mia the apparent rings are found to be of a different character, and 

 due to concentric or excentric zones of soft tissue called "false " 

 rings. A little practice will enable the student to recognise them 

 in most cases, for instance in Calophyllum (Penaga Puteh), Bin- 

 tangor bukit, B. batu, etc., and many Sapotaceae, Anonaceae, and 

 others, these partial zones are made up of wavy, pale bar like 

 markings, between the medullary rays. As to timbers with un- 

 doubted annual rings two chief types must be distinguished. 



(1.) The vessels in the spring wood are so large or numerous 

 as contrasted with the vessels in the autumn wood of the same 

 annual ring, that the boundary between the two is particularly 

 sharp, as in Oaks, Teak, Ash, etc. 



(2.) In the second type the ring is due to similar differences 

 between the fibrous and other elements of the wood rather than to 

 contrast of porous and dense wood, e.g., the autumn wood has very 

 thick walls and small lumina, while the spring wood has thinner 

 walls and larger lumina, as for instance Shorea robusta (the Sal of 

 India), Birch, Maple, Horse chestnut. 



The next character of importance is the presence or absence of 

 vessels, often called pores. (Care must be laken not to mistake 

 Resin canals for pores). Vessels are found in the wood of all 

 Dicotyledons with one exception, while they are as regularly absent 

 from that of the Conifers, consequently these two great groups can 

 be separated at a glance, at least with the aid of a lens. In dico- 

 tyledons, however, great differences occur in the vessels. Firstly, 

 as to size, the rule is that vessels are largest and most numerous 

 in the spring wood, diminishing outwards, but in one or two cases 

 this is the reverse. Secondly, as to the arrangement of the vessels, 

 and other characteristics, such as hardness, weight, grain, colour, 



