A<unk>  (plural<unk> es or<unk>  () is the primary sexual organ that male animals use to inseminate females (or hermaphrodites) during copulation. Such organs occur in many animals, both vertebrate and invertebrate, but males do not bear a<unk>  in every animal species, and in those species in which the male does bear a so-called<unk> , the<unk> es in the various species are not necessarily homologous. The term<unk>  applies to many intromittent organs, but not to all. As an example, the intromittent organ of most cephalopoda is the hectocotylus, a specialized arm, and male spiders use their pedipalps. Even within the Vertebrata there are morphological variants with specific terminology, such as hemipenes. In most species of animals in which there is an organ that might reasonably be described as a<unk> , it has no major function other than intromission, or at least conveying the sperm to the female, but in the placental mammals the<unk>  bears the distal part of the urethra, which discharges both urine during urination and semen during copulation.
Penis
Callus
Testicle
Menstrual pad
Pelvic floor
Vas deferens
Erethism
Ovary