Functional Anatomy and Physiology of Domestic Animals. Origins and Relationships of the Major Extant Clades. The clockwise coils are significant because the male phallus everts out of their body in a counter-clockwise spiral; therefore, a clockwise vaginal structure would impede forceful copulation. Archived from the original on 20 March Stallions have a vascular penis. Females have a small phallic organ in the cloaca which becomes larger during the breeding season.
Topics related to Penis.
Metallica Was Right About Suing Napster, Guitarist Says
None of these pitfalls appear to have fazed Creative Future, the huge coalition of entertainment industry companies with a mission to suck profit out of piracy and educate the masses. A Taxonomic and Geographic Reference. While most male birds have no external genitalia, male waterfowl Anatidae have a phallus. An Essential Guide to Birds of Europe. Tuataras must use their cloacae for reproduction. A number of invertebrate species have independently evolved the mating technique of traumatic insemination where the penis penetrates the female's abdomen and deposits sperm in the wound it produces. Wikimedia Commons has media related to Human penis.