抄録
The adrenal glands from April, July and November bullfrogs (Rana catesbeiana) were investigated cytologically on the preparations of tissues fixed with osmic acid solution, embedded in Epon and stained with toluidin blue. In the adrenal gland of the bullfrog two kinds of cortical cells were distinguished: the lipid cell containing many fat vacuoles, and the acidophilic summer cell loaded with acidophilic dense granules. In addition, the intermediary cell between the lipid and summer cell was successfully demonstrated. The identification of this intermediary cell was possibly due to the cellular characteristic that the dense granules are intermingled with abundant fat vacuoles. The dense granules were scattered in the cytoplasm, and gradually increased in number especially during the breeding and summer seasons. Eventually, the cell-body became full of dense granules, but lost the fat vacuoles. When this cell acquired an ellipsoid, or spherical contour, it turned into acidophilic summer cell. The occurrence of intermediary cell suggests the transformation of lipid cell into summer cell in the amphibian adrenals.
