The Y organs of Travancoriana schirnerae were pale yellow, translucent, conical epidermal structures were located in the cephalothoracic region. The histology of the gland consisted of anastomosing lobules of epithelial cells separated by interconnected blood sinuses and capillaries. Two distinct cell types -larger and smaller -contributed to the cytology of the gland. The organ included medium sized lobules separated by indistinct blood sinuses and capillaries in the intermoult stage. The early premoult organ was characterized by large lobules with complete obliteration of the interlobular spaces and prominent haemal sinuses and capillaries. The larger cells with increased cytoplasmic volume, perinuclear granulations and nuclei containing extensive large chromatin granules were the prodigious features during early premoult. These cells demonstrated secretory vesicles during D1 and D2 stages and their mode of release appeared to be holocrine in nature. The gland showed large number of vacuoles with signs of degeneration in late premoult (D4). The postmoult organ demonstrated smaller lobules with prominent interlobular spaces and indistinct blood sinuses and capillaries. Cellular degeneration and vacuolization were key features of the postmoult organ. Unilateral and bilateral eyestalk removal induced early premoult stages and produced marked changes in the morphology and histology of the organ during intermoult. In conclusion, the Y organ showed a cyclic change in activity in accordance with the moulting cycle.