THE STRUCTUKE OP WOOD. 



85 



constitutes the characteristic "grain" of striped mahogany, Fig. 23. 

 It is rarely found in the inner part of the tree. 



Sometimes the grain of wood is "cross," because it is "wav}'" eitlier 

 in a radial or a tangential section, as in maple, Fig. 25, and Fig. 2G. 



"Curly grain" refers to the figure of circlets and islets and con- 

 tours, often of great beaut\-, caused by cutting a flat surface in 



1' iy. /7. Curlv (iiained buiiy-Ieal -fine 

 (full size;. 



Fijf 2S. Curl3- Yellow Poplar 

 (full size). 



crooked-grained wood. See Fig. 27, curly long-leaf pine, and Fig. 28, 

 yellow poplar. When such crookedness is fine and the fibers are con- 

 torted and, as it were, crowded out of place, as is common in and 

 near the roots of trees, the cfl'ect is called "burl," Fig. 29. The term 

 burl is also used to designate knots and knobs on tree ti'unks. Fig. 31. 

 Burl is used chiefly in veneers. 



