Where the vesiculae join the ampullae of the vasa deferentia the ejaculatory ducts are formed; these are narrow and thin-walled, and run, side by side, through the prostate to open into the floor of the prostatic urethra.
They pass out through short vasa deferentia with internal ciliated funnels, sometimes an enlargement on their course - the seminal vesicles - and a minute external pore situated on the side of the tail.
The mouth is terminal or subterminal; there is a weak sucking pharynx situated behind the brain, and a long intestine lying along the medio-ventral body-cavity; it ends in a cloaca which receives the vasa deferentia in the male.
The paired oviducts and vasa deferentia are, as we have seen, mesodermal in origin.
Anteriorly their vasa deferentia soon unite into a common duct, which opens into the pouch containing the penes.
Extraordinary increase in length during the breeding season causes the vasa deferentia in some of the African weaverbirds to protrude, or to bulge out the cloacal walls beyond the vent.