JOURNAL OF THE JAPANESE FORESTRY SOCIETY
Online ISSN : 2185-8195
Print ISSN : 0021-485X
The electron-microscopic observation of xylary ray cells of conifer woods
Hiroshi HARADA
Author information
JOURNAL FREE ACCESS

1953 Volume 35 Issue 6 Pages 194-199

Details
Abstract
As is well known, the structure of the pit is of significance for the process of the diffusion in wood. In the present paper, an electronmicroscopic examination (by the replica) has been made of the fine structure of the pit membrane of a half-bordered pit pair or a simple pit pair (between a ray parenchyma cell and a tracheid), and of the fibrillar orientation in the cell wall of a ray parenchyma of an earlywood from a few Japanese conifer species including HINOKI-(Chamaecyparis obtusa), SUGI-(Cryptomeria japonica) and AKAMATU-(Pines densiflora) Wood. The 2-replica (the ethylmetacrylate-Al, Cr-shadowed method by TSUCHIKURA and AKATBORI (1952)) was made on the radial longitudinal surface of a piece of air-dried wood, obtained from crack by seasoning and tension perpendicular to the cell axis, and whittled by means of a microtome.
1). It has been supposed previously that the pit membrane of a simple pit pair or a halfborderd pit pair of conifer wood is formed by the middle lamellae and the adjacent primary walls, and that there is no evidence of a compound torus (Figs. 1. 2. 3 and 4). By the electron micrographs (Figs. 7. 8. 9. 10 and 13) it has been demonstrated that its pit membrane has not the so-called “Fäden” structure (by LIESE (1952)) (Fig. 6) as the pit membrane of a borbered pit pair of conifer tracheid but a vsimply membrane, and too, not the fibrillar structure (Figs. 7. 8. and 13). And therefore it is suggested that the diffusion through the pit membrane is very difficult in comparison withthat through the pit membrane of a borderd pit pair in coniferwood.
And it has been further shown that the inner surface in contact with cell lumen of the ray parenchyma both in heartwood and sapwood is covered with the some materials (contents), (Figs. 14. 15), and that only the marks of the pit aperture of the ray parenchyma cell is presented (Fig. 14).
2) It has been indicated that the cell wall of a ray parenchyma has two layers: one layer in which the f ibrills are oriented parallel to the longitudinal cell axis, and another one layer in which the angle of f ibrillar orientation is about 35° (Figs. 16 17.). It is probably assumed that the former layer corresponds to the broad layer in the secondary wall as WARDROP etc. (1952) reported, but that the place of the latter layer is not deter mined.
Content from these authors
© Japanese Forestry Society
Previous article Next article
feedback
Top