i8i 



CORNACE.E. 



Marlea ebenacea, C. B. Clarke. Lidah Kerbau Putih. 

 A big tree 60 to 100 feet tall. 



Wood hard and durable, yellow with a red heart and strong. 

 Used in building, giving beams 5 or 6 inches square. Maingay 

 gives the weight as 44 lbs. 9J ozs. 



M. nobtltSj C. B. Clarke. Sutubal. 

 A big tree 70 to 80 feet tall. Wood hard and durable, used in 

 building, giving beams 6 to 10 inches square. 



NOTES ON ANNUAL RINGS IN TIMBER. 



BY A. M. BURN-MURDOCK. 



Apropos of remarks in the editorial in the Agricultural Bulletin 

 No. 1 page 4, on timber rings, I think it might be of interest if I 

 give a brief outline of a classification of timbers proposed by Prof. 

 Marshall Ward, M. A., F. R. S., F. L. s., formerly professor of botany 

 at Cooper's Hill college. His aim is to classify timbers so that by 

 examination of the timber alone it may be identified. To do this 

 would require an expert in all but the commoner timbers but if his 

 method will at any rate teach us how to spot the common trees 

 with certainty, and give the outlines of a practical system of classi- 

 fication, it will be a step in the right direction. Tree Ferns, and 

 Cycads are of course omitted and only Conifers and Dicotyledons 

 dealt with. Before coming to the actual system of classification 

 the following phenomena should be observed. 



1. The pith, though not belonging to the wood, sometimes pre- 

 sents marked features, e.g., in Oak, the transverse section of the 

 pith is pentagonal or rayed, and chambered in Walnut. 



2. Comparison of heartwood with sapwood, here colour is 

 often very marked, e.g., in Ebony where the heartwood is black ; 

 Guaicum green ; Cesalpinia sappan, red ; Log wood, purple ; and 

 many others. 



3. Again some trees have peculiar discoloured patches or 

 spots known as medullary spots or pith flecks, looking like small 

 patches of rust in the wood such as are seen in Birches and 

 Hawthorns. 



4. Many conifers are distinguished by their resin canals, and 

 some Anarcadiaceae, but these resin canals have nothing to do 

 with true vessels of the wood, which will be mentioned further on. 



5. We must now consider Medullary rays. These are radial 

 stripes or rays, composed of cells elongated in a radial direction. 

 In a radial section these would appear as bands of small height, in 

 a tangential section, as elliptical group of cells. All Conifers and 

 Dicotyledons which form timber are provided with these rays, 

 which help greatly in the classification of timbers. Thus they may 

 be few and far apart as in Laburnum, Robinia, or numerous and 

 crowded as in Oaks, Rhodendron, maximum. Very narrow requir- 



