Dixon — Mahogany, Recognition of some Different Kinds. 469 



30. Clilorophora excelsa. 



No. 151, from Eoyal Gardens, Kew, labelled " CMoropkora excelsa Benth. 

 Uganda, 1905 ; Coll. M. J. Dawe." PI. XXXVI, figs. 88, 89, 90. 



Ochre- brown, dull, roey, hard. Vessels not zoned. Fibres in C. S. brown. 

 Parenchymatous laminae buff-yellow, thick and undulating, connecting and 

 surrounding vessels ; also occasional thin laminae, straight, about 3 mm. 

 apart, not specially connecting vessels. Pays buff and distinct. 



C.S. — Vessels tangentially compressed, isolated, or in small radial groups, 

 '• divided."— M. T. D. = 027 mm. 6-10 in 2-mm. field ; with tyloses. — Fibres 

 thick-walled, irregular ; 3-20 between rays. — Circumvasal parenchyma con- 

 spicuous, spreading tangentially into thick undulating laminae devoid of 

 dark contents ; about 10 cells thick ; laminar parenchyma about 6 or 8 cells 

 thick, radially compressed. — Pays conspicuous, without dark contents. 



T.S.— Rays irregular in size and arrangement, sides bowed ; about 65 in 

 2-mm. field. Total width in 2 mm. = 0-44 mm. Height = 0-07-0-32-0-55 mm. ; 

 4-30 cells. Width = 0-01-0-07 mm. 1-, 2-, 3-, 4-, 5-, 6-, 7-, 8-ply. Margin 

 distinct, usually 1 large cell deep, often with crystal. Middle cells thick- 

 walled with small round lumen. No dark contents. — Fibres non-septate, 

 3-12 between rays. 



R.S. — Parenchyma rectangular.— Fibres non-septate. — Pay margins with 

 conspicuous row of crystals. 



Note. — The ochre-brown colour and lack of lustre, together with the 

 presence of massive circumvasal parenchyma, distinguish this wood from 

 other commercial mahoganies. It is included here, as it is often listed 

 among the African mahoganies or mahogany substitutes. 



31. Baillonella cljava. 



No. 289, from commercial source, labelled " African Pear tree, Duka or 

 Douka = Baillonella djava Pierre, also called Indouka and Manioka. Natural 

 Order Sapotaceae." PI. XXXVI., figs. 85, 86, 87. 



Red-brown, no zonation apparent in small sample. No parenchymatous 

 laminae visible, lustrous, without roe. Sp. gr. - 76. 



C.S. — Vessels slightly compressed tangentially in radial groups or in 

 indistinct echelons of 4-6. M.T.D. - 18 mm. About 20 groups in 2-mm. 

 field. With tyloses. — Fibres thick-walled, polygonal, compressed radially in 

 occasional tangential zones. — Circumvasal parenchyma indistinct. Paren- 

 chymatous laminae 1 cell thick, about O'lo-O^O mm. apart, sometimes with 

 dark deposit. — Rays conspicuous, narrow, with dark contents often appearing 

 to end at parenchymatous lamina or zone of compressed fibres, 



