Page:The Oak.djvu/77

Rh 15.— Tangential longitudinal section of wood of oak (highly magnified). To the left is a large medullary ray (M.Str), and numerous small ones are seen in various parts of the section—of course, in transverse section. Librf, wood-fibers; Gef, smaller pitted vessels; Trach, tracheids; H.P., wood-parenchyma. (Kny.)