Qucrcus alba (white oak): cross section (hrough one entire growth ring and 

 portions of two others. Note large pores in early wood filled with tyloses and 

 abruptly diminishing in size toward late wood. Small pores thin-walled and in 

 fan-like .groups. Note "dipping in" of the outline of the growth ring where it 

 crosses the large ray at the right X 35. 



