312 APPENDIX IV 



true concentric rings of lighter and darker wood, the pores in the former 

 being more numerous and larger ; but it is not likely that these rings con- 

 stitute the spring- and summer-wood of a year's growth. The pith-rays are 

 very numerous, very fine, uniform, equidistant, and wavy, about the width 

 of a pore apart ; and the pores are small, but variable in size, sometimes in 

 groups of two or three, and appearing green from the resin which they exude. 

 The narrow yellow sapwood is sharply contrasted with the dark-brown 

 heart. 



Plates VIII. to XII. represent types of tropical timbers in which there 

 are neither true annual rings nor false rings. AlUzzia 'procera (Plate VIII.), 

 the White Siris of India, belonging to the same genus as the so-called East 

 Indian Walnuts {A, Lehbek, etc.), is a leguminous wood, closely alHed to 

 Mimosa, hard, though quick-grown. The sapwood is wide and yellowish- 

 white, the heart brown, with ill-defined alternating lighter and darker bands. 

 The pith-rays are few, fine, and, except where diverging round the pores, straight. 

 The pores are large, uniformly distributed, sometimes divided radially into 

 two, and always surrounded by an " areola," or round patch, of soft tissue. 



Plate IX. — Nectdndra Eodmi, the Greenheart of Demerara— is a repre- 

 sentative of the Laurdcece. It is a very heavy, very hard, dark greenish- 

 brown wood, almost black, with few, fine, uniform, gently undulating, equi- 

 distant pith-rays, and a moderate number of large, uniformly distributed, 

 yellowish-green pores. These pores are mostly subdivided or grouped together 

 in threes or fours, filled with yellowish-green resin, and surrounded by small 

 patches of soft tissue, so that — but for the pith-rays — ^the transverse section 

 has, as Laslett says, " the appearance of cane." 



Hopea odordta, the Thingan of India (Plate X.), is a member of the Order 

 DipterocarpdcecB, which comprises several of the largest and finest of Indian 

 forest-trees. They are generally hard, brown, and resinous, with fine or 

 moderately broad pith-rays, producing a good silver grain, and large resin- 

 filled pores, each surrounded or " ringed " by a narrow band of loose tissue 

 made up of large wood-cells. In the genus Hopea the wood is yellowish- 

 brown and even-grained, and there is some slight variety in the size of the 

 pores. In our plate it will be noticed that the pith-rays vary in width, 

 though none of them are wide, and that there are deHcate Httle transverse 

 lines or bars of small elements joining them at right angles. In one place 

 these transverse bars are represented by a decided band. 



The wood of Lophira aldta, the African Oak (Fig. 33, p. 47), is another 

 representative of this Order. Here the soft tissue forms fine, undulating, 

 concentric fines, and there are very numerous, excessively fine, wavy pith- 

 rays. The pores are not numerous, but mostly large, in groups from two to 

 five together, many filled with a whitish chalky substance, conspicuous 

 against the blood-red colour of the wood. 



The Order Bapotdcece, of which Sideroxylon horhonicum (Plate XI.) is an 

 example, is one of considerable importance not only as containing timber- 

 trees, but also as that to which the Guttaperchas belong. The woods in this 

 Order resemble those of the Ehendcece in structure, but differ in beiDg usually 



