THE AUSTRALIAN GREY MANGROVE. 269 



(c) Macroseopical. — -Viewing a transverse section of a 

 mature tree, (Plates XXXVI, XXXVII, figures 10 and 11) 

 the annual "rings" as obtains in ordinary dicotyledonous 

 stems might be said to be well defined, but with this differ- 

 ence, that the "rings " are not continuous, the break being 

 caused by an intrusion of another "ring," and thus the 

 complete circle is broken. 



By forcing the "rings" apart tangentially a good view 

 is obtained of the disposition of the fibres. Each ring of 

 fibres is seen to be at quite a different angle to that in 

 juxta-position to it. Sometimes they run perpendicularly 

 but more often at varying angles to each opposing ring, 

 (Plate XXXVIII, figure 12). 



Dr. Prain's remarks in his "Flora of the Sandabans," 

 1903, apply equally well to this Australian Mangrove: — 



" The structure of the wood is peculiar, in that the fibres of 

 any particular ring of growth do not pass vertically upwards, but 

 instead diverge 'herring-bone fashion" from an indistinct vertical 

 linear raphe, which appears to correspond to the plane of an 

 original branch, at an angle of about 15°, their upper ends blend- 

 ing in a much less definite raphe mid-way between two raphes of 

 divergence. The raphes of divergence of the ring of growth next 

 above and next below any particular ring alternate, so that in 

 weathered trunks, and to a less extent in freshly cut sound logs, 

 a lace-work arrangement of the fibres of the various rings of growth 

 presents itself." 



The structure of the timber much resembles what is to-day 

 on the markets as three, four, or five-ply veneer, which 

 can now be shown to be only a copy of nature, for in the 

 manufactured article the fibres of each sheet of wood are 

 at right angles to one another instead of at oblique angles, 

 as obtains in nature, which, is the main reason for the 

 difficulty in splitting. 



