Studies on the accessory reproductive organs in the drake. 3. Ejecting mechanism of the fluid from the ejaculatory groove region.

The ejecting mechanism of the fluid from the ejaculatory groove region (EGR-fluid) of the drake was investigated. When Evans blue solution was injected into the wing wein, EGR-fluid was colored blue with the dye soon after injection. Ligation of the A. pudenda interna decreased the oozing volume of the fluid to a negligible amount and excision of the vascular body completely suppressed the erection of the penis. To investigate the ejecting course of EGR-fluid, Evans blue solution and India ink were injected into the A. pudenda interna and just beneath the epithelium of the ejaculatory groove region, respectively, using cloacal specimens. Injected Evans blue solution flowed out from the ejaculatory groove region and the particles of ink were observed to have lined between the epithelial cells. From these results, the following assumption might be made. Lymph generated in the vascular body causes the erection of the penis only and a lymph generated the tissue of ejaculatory groove, region to which blood is supplied from the A. pudenda interna is ejected from the epithelium of this region through the intercellular space of it. The ejected lymph is considered to be the EGR-fluid to be added to semen at copulation.