24 GUIDE TO TIMBERS OF NIGERIA 



eye, and (b) abundant in concentric, undulating lines connecting 

 the pores, occasionally interrupted and anastomosing ; width 

 equal to about half the diameter of a pore ; 3 per radial mm. 

 at intervals of about two pore-diameters ; distribution fairly 

 even ; proportion of the wood about one-fifth. Many crystals. 



Vessels visible as perforations, medium, no appreciable 

 diminution in size ; number per sq. mm. 6-8 ; a tendency to 

 an echelon arrangement ; simple, or in radial groups of 2-4 

 pores, mostly the former ; very few ; widely isolated, only 

 about ten to fourteen groups in the field of the macroscope. 

 Shape, oval ; colour, light. 



Rays just visible, very fine ; of one kind only ; regular in 

 size and spacing ; rather weak and avoiding the pores ; colour, 

 nearly as pale as the P. (a) ; proportion of the wood from one- 

 fifth to one-sixth. Number of rays per mm. 10-14. 



Ground-tissue-cells hardly visible with macroscope ; pro- 

 portion of the wood rather more than one-half. 



Rings undefined ; contour regular. 



Radial section. Colour a hoary yellow (yellow and white 

 in alternate lines and patches) ; grain, coarse, fairly straight, 

 empty for the most part, but perhaps a little resin is present. 

 P. (b) just visible as parallel, vertical, hoary lines, which by 

 their closeness and abundance affect the tone of the section. 

 Rays just visible by slight contrast of colour. 



Tangential section as the radial, but the P. broadens out 

 very much and becomes the feature of the section ; the cells 

 are visible with macroscope. Rays minute^ mostly uniseriate ; 

 variable in size ; not in parallel ; their ends are hoary like the 

 P. ; height about 24 cells. 



Pith, sapwood and bark absent from specimens. 



Density, No. 3014, 1-125 or 70 Ib. per cubic foot. 

 3269 1-06 66 



Conservator's note. " An evergreen tree found in the ever- 

 green and mixed deciduous forests. Not very plentiful. 

 Timber heavy and dense ; very little used." 



Guarea sp. Mcliacese. Gen. No. 1178. 



NOTE. This is possibly G. Thompsonii. In the list supplied 

 to us by the Chief Secretary of Nigeria the specimen No. 4 

 Benin (our 4035) appears under the heading of Guarea Thomp- 



