Structure of the Vegetative Shoot Apex of Clethra barbinervis

III. Longisectional View, Summary Analysis and Discussion

抄録

The vegetative shoot apex ofClethra barbinervisSieb. et Zucc. was analyzed in longisectional view and discussed from the viewpoint of the three-dimensional aspect. The width of the central zone fluctuates during a plastochron but the depth scarcely changes. The beginning of leaf initiation is recognized in a very early stage of growth even in longisectional view, if sector development is carefully examined. When two reconstructed and overlapped figures for the first cell layer of the apex are depicted, changes occurring at the apex in the superficial view come to be easily understood. Moreover, if the shoot apex is analyzed for T divisions, a type of analysis recommended for the root apex by Schüepp (1917), anatomical changes of the apex are
fairly well understood even from the viewpoint of the three-dimensional aspect.