THE SEASONAL VARIATIONS IN THE ADRENAL CORTEX CELLS OF BULLFROG, WITH SPECIAL REMARK TO THE ORIGINATION OF THE SUMMER CELL

Abstract

The seasonal variation in the adrenal cortex cells of bullfrog was studied histologically in order to ellucidate the origination of the summer cell. In frogs, the lipid cells rich in lipid granules and the spherical eosinophilic summer cells are distributed irregularly in the anastomosing cords without making the discrete zonation. The summer cells are numerous in April and July. Especially in April frogs, the cortex is full of hypertrophied summer cells containing the big granules strained with orange-G. The total number of summer cells is highest in April. The lipid cells decrease in number when the summer cells multiply. Simultaneously the immature lipid cells devoid of fat granules appear in clusters. In March the summer cells are pale because of poor acidophilic granules. In Sept., Nov. and Feb. frogs, abundant lipid cells represent either compact or heavily vacuolated type. In addition, the intermediate cells between summer and lipid cells are often encountered. These cells are polygonal or angular in shape and they are provided with the acidophilic granules. There is a morphological evidence favorable to the view that the summer cells are independent of the extra-adrenal granulocytes and might be derived from the lipid cells by storing the acidophilic granules.