Abstract
The authors performed histological studies on the bast tissue, especially primary and secondary fibre layers of paper mulberry (Broussonetia Kazinoki and B. Papyrifera). Results are Summarized as follows: 1) Primary fibre layer has reticulate structure, which is made from many fibre bandles, consist of 5 to 30 primary fibre cells. 2) Primary fibre layer and secondary fibre layer are separated clearly with middle layer. 3) Thickness of the bast tissues at various positions on the same shoot are measured and tendencies to increase and decrease of these became clear. 4) Characters of varieties and histological differerences between Kozo (B. kazinoki) and Kazinoki (B. papyrifera) are recognized as table 3.
