抄録
(1) The writer studied on the developmental process and the pyrethrin content of the oilgland and secretory duct in'Chrysalcthemum cinerariaefolium VISIANI. (2) The oilgland is formed by division of one epidermiscell. That is, this epidefrnis cell grows up to be the oilgland mother cell, then this mother cell differentiaies into eight oilglands and two stalk cells after continous divisions. At the same time the epidermis mernbrane covering the oilgland expands remarkably as both these glands and cells reduce in their size. Thus the oil chamber is formed and resinous substances are accumulated in it. (3) The secretory duct is the intercellular. space which was formed between parenchmatous cells along the vascular. The ducts arise mainly in the ovary wall. There is a positive correlation between the number of secretory ducts and the pyrethrin content. It seems possible, therefore, that the pyrethrin content is forecast by observing the quantity of resinous substances in ducts.
