THE WOOJ) 



223 



running from the bark toward the center, or pith. They 

 are the pith rays. If we examine the side of the board, 

 they look hke broad bands if the board is quarter-sawed 

 or rift, and as short brown lines if ])astard or tangent. 



bark 



Fig. 82. Alternating; Spiral Grain in Cypress. (Side and end 

 view of same piece) 



When the bark was at o the "rain at this point was straight. From that time 

 each year it grew more oblique in one direction, reaching a climax at a, and 

 then turned back in the oi)posite direi-tion. These alternations were repeated 

 periodically, the bark sharing in these changes 



