Abstract
This paper deals with the morphological evidence of the independency of the adrenocortical cells in bullfrogs from pituitary control. Male adult bullfrogs (Rana catesbeiana) were hypophysectomized during the hibernation period. Six days after hypophysectomy atrophy of cortical cells was indistinct: the spherical summer cells of Stilling containing lots of acidophilic granules increased in number, in particular remarkably so in the deeper areas of the gland, and the polygonal possible “intermediate cells” between the summer and the lipid cell multiply simultaneously. Nine days after the removal, lipid cells were not yet profoundly degenerated, but the heavily vacuolated lipid cells were more frequently found. On the contrary, summer cells decreased in number and lost their acidophilic granules. Irrespective of hypophysectomy, mitotic cells were often detected in the immature lipid cells. When bullfrogs were hypophysectomized during the breeding period and post-spawning season, the lipid and acidophilic summer cells underwent no affections 10 days after the operation. Thus, the intrinsic seasonal variation during the breeding period and post-spawning period was not modified by hypophysectomy. The neoformation of lipid cells following hypophysectomy during the hibernation period suggested that the adrenocortical cells in bullfrogs might be less controlled by the hypophysis.
