Chapter X.
Wood.
113. Structure.
—For convenience, tree structure is usually studied (1) in transverse or cross section, (2) radially, (3) tangentially.
| V.—Vessels or pores. | ||
| T.S.—Tangential | Section. | |
| C.S.—Transverse | „ | „ |
| R.S.—Radial | „ | „ |
Fig. 193.
A transverse section is obtained by cutting a log at right angles to its length; a radial section by cutting it along the radius; a tangential section by making a cut at right angles to a radius. [Fig. 193].
Fig. 194.
If we should cut transversely a young tree, a sprout, or branch of an oak or similar tree, we should find it composed of three layers of tissue (1) pith or medulla, (2) wood, (3) bark, [Fig. 194]. These tissues, if magnified, would be found composed of little closed tubes or cells. [Fig. 195].