GUIDE TO TIMBERS OF NIGERIA 27 



Our specimens bearing similar names do not agree with this 

 species, though they are undoubtedly of the same genus. 



Description of the wood from a specimen No. 3103 sent by 

 the Government of Nigeria (Empire Timber Exhibition, 1920). 



GENERAL CHARACTERS. A wood of medium weight and 

 hardness resembling a Mahogany of fair quality. Colour red 

 or reddish -brown, inclining to pink when freshly worked ; it 

 deepens and improves on exposure. Surface bright on all 

 cuts, dry, hardly likely to soil. . Grain, coarse, open, exceedingly 

 tortuous, and very roey. Shade of the -trans verse section much 

 as that of the other sections. Smell, none. 



STRUCTURE. Resembles that of Swietenia. 



Transverse section. (Prepared with glass-paper.) 



Parenchyma of two kinds : (a) vasicentric, and (c) simulating 

 the ring-boundaries. 



Parenchyma (a) not 'visible to the unaided eye, needs lens 

 as it lacks contrast of colour ; very light pink ; does not extend 

 laterally to wings. 



Parenchyma (c) occasionally visible without lens as fine 

 concentric lines, but very difficult to see for the most part ; 

 width of lines about the radial diameter of a large pore ; con- 

 tinuous ; colour rather less pink than the P. (a). 



Vessels readily visible as perforations, large, diminishing in 

 size from the inner to the outer side of the ring and variable 

 in number 2-7 per sq. mm. ; widely isolated except in the 

 inner zone of the ring where the pores are often collected into 

 a quite definite pore-ring of rather larger pores (the only species 

 of Mahogany in which we have seen this). Arrangement 

 indefinite. Some twinned pores, but mostly simple ; oval in 

 shape. Contents black. Proportion of the wood, including 

 Parenchyma (a), about one-fifth. 



Rays readily visible from their red colour and size, fine, 

 similar in colour to the P. (a) ; fairly regular in size and spacing ; 

 rather weak ; intervals about three times the width of a ray ; 

 4-6 per mm. Contents ? Proportion of the wood about 

 one-fifth. 



Ground-tissue-cells readily visible with macroscope ; colour, 

 dull grey-brown ; contents shine like minute beads. 



Rings very ill-defined, boundaries traceable with difficulty, 

 except at long intervals ; contour regular. 



