Close to the opening of the utriculus the ejaculatory ducts, already mentioned, open into the urethra by very small apertures.
2
On the other hand, the ejaculatory duct with its verticillate sac in the male of Cypris and other genera is a feature scarcely less remarkable.
3
The ejaculatory duct which opens on the ninth abdominal sternum in the adult male arises in the tenth abdominal embryonic segment and subsequently moves forward.
4
The median vagina, spermatheca and ejaculatory duct are, on the other hand, formed by ectodermal inpushings.
5
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.