36 WOOD AND FOREST. 



Irregularity of grain is often caused by the presence of adventi- 

 tious and dormant buds, which may be plainly seen as little knobs 

 on the surface of some trees under the bark. In most trees, these 

 irregularities are soon buried and smoothed over by the successive an- 

 nual layers of wood, but in some woods there is a tendency to pre- 

 serve the irregularities. On slash (tangent) boards of such wood, 



Fig. 29. Redwood Burl (full size). Fig. 30. Bird's-eye Maple (full size). 



a great number of little circlets appear, giving a beautiful grain, as 

 in "Bird's-eye maple," Fig. 30. These markings are found to pre- 

 dominate in the inner part of the tree. This is not at all a distinct 

 variety of maple, as is sometimes supposed, but the common variety, 

 in which the phenomenon frequently appears. Logs of great value, 

 having bird's-eyes, have often unsuspectingly been chopped up for 

 fire wood. 



