collected at wide intervals, probably the boundaries : they 

 appear as fine, well-rounded, concentric, white lines. 



Ground-tissue. Very spongy and coarse, the cells being as 

 large as those of many Conifers, equal to size 4 (pore-scale) : very 

 uniform and in radial rows. 



Soft-tissue. Abundant in the form of concentric fragments 

 winging and often linking the pores : white : size about 5 (ray- 

 scale) : as dense as the ground and imperceptible in a transparent 

 section though visible with care in the solid : absent throughout 

 large areas. 



Pith. ? 



Radial section. Whiter than the transverse section. Pores 

 prominent : brownish, rather coarse and dull. Rays very fine, 

 inconspicuous, narrow, shining flakes yet readily visible. Rings 

 and soft- tissues not traceable. 



Tangential Section. As the Radial, but the rays are just 

 visible, extremely fine lines about '5 mm. high : very narrow 

 even for their size. 



Type specimen authenticated by the Forest Officer to the 

 Government of British Guiana. (Fig. 18, PI. II, serves for this 

 species also.) 



No. 25. QUASSIA. Picraena excelsa. Lindl. 



PLATE II. FIG. 18. 



Natural Order. Simarubeae. 



Alternative Names.' Bitter-wood. Bitter Ash. Bitteresche. 

 (Compare also those of Simaruba). Quinquina de Cayenne (21). 



Sources of Supply. West Indies, Guiana, Brazil. 



Physical Characters, etc. Recorded dry-weight 33|~34f Ibs. 

 per cu. ft. Hardness, Grade 8, compare White Pine (P. Stro- 

 bus) and Poplar. Smell none. Taste intensely bitter. Burns 

 well without smell : embers glow in still air. Solution with 

 water or alcohol colourless. 



Grain. Rather fine, open. Surface beautifully lustrous, the 

 ground brilliant : the rays shining and the pores dully-shining 

 when empty. 



Bark. " Similar to that of the Common Ash " (109). 



Uses. Medicinal, a bitter-tonic. Sometimes made into cups 

 in which water is allowed to stand and become bitter. Not used 

 for joinery in Europe. Maybe met with in logs from6-io feet 

 long by 6-10 inches diameter. Usually confused with Simaruba, 

 from which it is distinguishable with great difficulty. 



Authorities. Gamble (37), p. 63. J. Smith (in), p. 342. 

 Holtzapffel (48), p. 103. Sinclair (109). Charpentier (21), p. 

 156. Wiesner (131), L. 12, p. 95. 



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