more obscure
*
Plate IV. Transverse section of river birch through pith fleck, showing connection between wound tissue and pith rays. Magnified 150 diameters.
(cropped from border and to square; rotated 0.4ยบ cw; color discarded; printed orientation)
in H(arry). P(hilip). Brown (1887-1951), Xylotomist. Pith-Ray Flecks in Wood. USDA Forest Service Circular 215 (May 7, 1913)
this from USDA National Agricultural Library copy
opens to same page in USFS Circulars, issues 211-216,
UCLA copy, digitized Nov 10, 2014 (panoramic thumbnail)
“The relation, however, of the vessels to wound tissue is more obscure.” p 9
tags:
deterioration; obscurities; river birch; vessels; xylotomy
H. P. Brown, Pith-Ray Flecks in Wood (1913)