Studies on the accessory reproductive organs in the drake. 2. Macroscopic and microscopic observatorys on the cloaca of the drake with special reference to the ejaculatory groove region.

The anatomical structure of the ejaculatory groove region (EGR) of the drake was investigated macro- and microscopically in connection with its function. The EGR covers a part of the urodeum and the second fold of the cloaca. The EGR is unique to the males and is characterized by red colored appearance and less smooth surface of the mucosa. The mucosa of EGR forms folds giving less smooth surface to it and is lined with psuedostratified columnar epithelium. A vascular layer which contains many capillaries and lymphocytes and gives red color to the mucosa lies just beneath the epithelium. The EGR develops at puberty together with the developments of the testis and the penis. Blood supply and the arrangement of the lymphatic sinuses of EGR were described and their functions were discussed.