Chromaffin tissue in the adrenal gland of the toad, Bufo arenarum Hensel

In the present work the topography of the toad's adrenal is described. The gland consists of a branching system of cellular cords, sinusoid capillaries, and a venous system. The cords are made up of cortical cells and chromaffin cells. The latter can be classified in two morphological types. Type I cells are elongated, and have a smooth contoured nucleus and polymorphic chromaffin granules, a majority of which have a spherical shape. Type II cells are polygonal with an irregular nucleus and elongated chromaffin granules. Type I and Type II cells contain small mitochondria, lysosomes, and a juxtanuclear canalicular system (endoplasmic reticulum and Golgi complex). The probable role of the Golgi complex in the genesis of the chromaffin material as well as the significance of membrane-bounded granules in the walls of the capillaries are discussed.