280 THE BOOK OF FORESTRY 
On cutting across a log in addition to the-annual 
growth rings laid on each year by the cambium layer, 
grayish lines may be seen extending from the heart to ~ 
bark. These lines, called ‘‘medullary rays,’’ are made up 
Courtesy H. P. Brown 
Fig. 64.—Section of a non-porous coniferous wood (sequoia), seen 
through a microscope. The dark band marks the late summer growth. 
of thin-walled cells like the pith in the center. In some 
hardwoods, like oak, syeamore and maple, these medul- 
lary rays are very broad and conspicuous, especially 
when cut along the radius—“quarter-sawed”—which 
shows them off to best advantage. In the softwoods 
