96 GUIDE TO TIMBERS OF NIGERIA 



FIG. 9. Nested (mother-and-daughter) groups sufrounded by 



Parenchyma (a). 

 FIG. 10. Block of wood showing the tangential section where 



the rays appear in parallel lines (" storied " or " palisade " 



arrangement). 

 FIG. 11. Block as in fig. 10, but the rays are arranged alternately 



in " quincunx." They are, however, all about the same 



height as in previous figure. 

 FIG. 12. As fig. 11, but the difference in height of the rays varies 



very much from point to point. 

 FIG. 13. The rays in this case are more or less uniform in height, 



but they are arranged in oblique lines or in echelon. 



PLATE II 



TRANSVERSE SECTIONS, PITH SIDE DOWNWARDS, x. 3, PHOTO 



GRAPHED FROM THE SOLID WOOD BY A. J. WlLSON 



FIG. 1. Lophira. Shows widely isolated vessels sheathed with 

 and connected by gently undulating, narrow zones of Paren- 

 chyma (a), the so-called "perivasal, vasicentric or para- 

 tracheal " Parenchyma. This photo serves for Klainedoxa also. 



FIG. 2. Pterocarpus. A type serving for all species of the same, 

 and several allied genera of Leguminosse, e.g., Baphia (Cam- 

 wood). It is generally accompanied by rays in palisade 

 (storied) rays. The resemblance of this type to fig. 1 is 

 superficial only. 



FIG. 3. Paradaniellia. A modification of type in fig. 2. The 

 lines of P. (a) are more interrupted in certain zones. 



FIG. 4. Guarea. The lines of P. (a) are more ragged in contour 

 than in the previous figures. The lines vary in thickness, 

 spacing, and regularity, from place to place, according to 

 differences in the rapidity of growth. 



FIG. 5. Garcinia. The lines of P. (a) are still more ragged in 

 contour than in previous figures, and the tendency to run 

 obliquely and to branch is greater, making loose festoons. 

 (The white line to the left is a crack in the wood.) 



FIG. 6. Chlorophora. The P. (a) is very well developed and 

 forms broken festoons and more or less continuous boundary- 

 like lines at intervals. 



PLATE III 



TRANSVERSE SECTIONS, PITH SIDE DOWNWARDS, x. 3, PHOTO- 

 GRAPHED BY A. J. WILSON FROM THE SOLID WOOD 



FIG. 1. Cylicodiscus (pith side to the left below). The P. (a) 

 sheathes the vessels but does not connect them. Radially- 

 oblique scries of vessels arc well shown reversing their direction 

 from zone to zone. 



