Ghosh and kar (1952)have described the testicular cycle of Heteropneustes fossilis. But there is no reference to the sea-sonal periodicity of the seminal vesicles. The seminal vesicles were observed in the male Heteropneustes in connection with the studies on the correlation between the structure of the pituitary gland and the sea-sonal changes in the testes (Sundararaj, 1958). Accessory glandular structures to the testis of fishes have received very little attention. Rathke (1824) was the first to re¬port on the seminal vesicles of Gob ius niger. Disselhorst (1904) noticed seminal vesicles in only large males of Esox lucius and these observations were made during the spawning time. Eggert (1931) described the structure and the histology of the seminal vesicles of Periophthalmus chrysospilos