The annual interrenal tissue cycle within the adrenal galnd of the Eastern Rosella, Platycercus eximius (Aves : Psittaciformes)

Abstract

The annual cytological changes in the interrenal (cortical) tissue of the adrenal gland of P. eximius (Shaw) have been studied. The ratio of interrenal tissue to total endocrine tissue, here designated the fractional cortical volume, shows an annual cycle which is highly correlated with the maturation of the gonads and the onset of the breeding season. These results are discussed in relation to other published studies on interrenal tissue cycles in avian species.