:Penis

The word "penis" is taken from the Latin word for "tail". Some derive that from Indo-European *pesnis, and the Greek word πέος = "penis" from Indo-European *pesos. Prior to the adoption of the Latin word in English, the penis was referred to as a "yard". The Oxford English Dictionary cites an example of the word yard used in this sense from 1379,{{cite book |last1=Basu |first1=S. C. |title=Male Reproductive Dysfunction |date=2011 |publisher=JP Medical Ltd |isbn=9789350252208 |page=101 |url=https://books.google.com/books?id=BoL2I7yg67cC&q=Simpson,+John;+Weiner,+Edmund,+eds.+(1989).+%22yard,+n.2%22.+Oxford+English+Dictionary&pg=PA101 |language=en}} and notes that in his Physical Dictionary of 1684, Steven Blankaart defined the word penis as "the Yard, made up of two nervous Bodies, the Channel, Nut, Skin, and Fore-skin, etc."{{Cite book|title=Oxford English Dictionary|contribution=penis, n.|contribution-url=http://dictionary.oed.com/cgi/entry/50174565|publisher=Oxford University Press|editor-last=Simpson|editor-first=John|editor-link=John Simpson (lexicographer)|isbn=978-0-19-861186-8|year=1989|edition=second|title-link=Oxford English Dictionary}}{{Dead link|date=June 2013}} According to [https://en.wiktionary.org/wiki/%C8%9Derde#Middle_English-bar Wiktionary], this term meant (among other senses) "rod" or "bar".

As with nearly any aspect of the body involved in sexual or excretory functions, the penis is the subject of many slang words and euphemisms for it, a particularly common and enduring one being "cock". See WikiSaurus:penis for a list of alternative words for penis.

The Latin word "phallus" (from Greek φαλλος) is sometimes used to describe the penis, although "phallus" originally was used to describe representations, pictorial or carved, of the penis.{{cite web |url=http://www.etymonline.com/index.php?search=penis&searchmode=none |title=Online Etymology Dictionary |publisher=Etymonline.com |access-date=2011-05-28 |url-status=live |archive-url=https://web.archive.org/web/20110606085622/http://www.etymonline.com/index.php?search=penis&searchmode=none |archive-date=2011-06-06 }}

{{CSS image crop|Image=Tiger_Tadoba_NP.jpg|bSize=880|cWidth=280|cHeight=110|oTop=230|oLeft=560|Description=A tiger's penis is aimed backward during urination. Tigers scent-mark their territories with pheromones in urine.{{Cite book |last=Watson |first=Lyall |url=https://books.google.com/books?id=e_KPAgAAQBAJ&pg=PT36 |title=Jacobson's Organ: And the Remarkable Nature of Smell |date=2000-04-17 |publisher=W. W. Norton & Company |isbn=978-0-393-24493-9 |language=en}}}}

The external genital organs appeared in the Devonian, about 410 million years ago, when tetrapods began to abandon the aquatic environment.{{cite book|last1=Dunlop|first1=Jason A.|last2=Penney|first2=David|title=Fossil Arachnids|date=2012 |url=https://books.google.com/books?id=16Zed-dC1OYC&pg=PA44|page=44|publisher=Siri Scientific Press|isbn=978-0-95677-954-0}} In fact, the necessity to overcome the absence of a liquid phase in which to release the gametes was achieved through the transition to internal fertilization.

Among amniotes, the development of an erectile penis occurred independently for mammals, squamates (lizards and snakes), testudines (turtles), and archosaurs (crocodiles and birds).

Over time, birds have lost this organ, with the exception of Paleognathae and Anseriformes.{{cite book|last1=Cordoba-Aguilar|first1=Alex|last2=Leonard|first2=Janet|title=The Evolution of Primary Sexual Characters in Animals|year=2010|pages=216–221|publisher=Oxford University Press|url=https://books.google.com/books?id=PgtXj5R6OfMC|isbn=978-0-19971-703-3}}

The penis is an intromittent organ used to transfer sperm into the female genital tract (i.e., vagina or cloaca) for potential fertilization. The penises of different animal groups are not homologous with each other, but were created several times independently of each other in the course of evolution.

An erection is the stiffening and rising of the penis, which occurs during sexual arousal, though it can also happen in non-sexual situations.

During ejaculation, a series of muscular contractions delivers semen, containing male gametes known as sperm cells or spermatozoa, from the penis. Ejaculation is usually accompanied by orgasm.

The last common ancestor of all living amniotes (mammals, birds and reptiles) likely possessed a penis.{{cite journal |vauthors=Sanger TJ, Gredler ML, Cohn MJ |date=October 2015 |title=Resurrecting embryos of the tuatara, Sphenodon punctatus, to resolve vertebrate phallus evolution |journal=Biology Letters |volume=11 |issue=10 |pages=20150694 |doi=10.1098/rsbl.2015.0694 |pmc=4650183 |pmid=26510679}}

{{anchor|Birds}}

{{multiple image

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| image1 = Bird sex - Two copulating ducks showing a corkscrew penis inserted in a cloaca in Don Det Laos.jpg|thumb|Copulating ducks showing a corkscrew penis inserted in a cloaca.

| image2 = Duck Reproduction.svg|thumb

| footer = Male ducks have a corkscrew-shaped penis to match the females' corkscrew vaginas. This favors fertilization by fitter mates over unwanted aggressors.{{Cite journal |last1=Brennan |first1=Patricia L. R. |last2=Clark |first2=Christopher J. |last3=Prum |first3=Richard O. |date=2010-05-07 |title=Explosive eversion and functional morphology of the duck penis supports sexual conflict in waterfowl genitalia |journal=Proceedings of the Royal Society B: Biological Sciences |volume=277 |issue=1686 |pages=1309–1314 |doi=10.1098/rspb.2009.2139 |issn=0962-8452 |pmc=2871948 |pmid=20031991}}}}

Most male birds (e.g., roosters and turkeys) have a cloaca (also present on the female), but not a penis. Among bird species with a penis are paleognaths (tinamous and ratites){{cite book|author=Julian Lombardi|title=Comparative Vertebrate Reproduction|url=https://books.google.com/books?id=cqQX9RMPAegC&q=penis|access-date=5 December 2012|year=1998|publisher=Springer|isbn=978-0-7923-8336-9|url-status=live|archive-url=https://web.archive.org/web/20140326171659/http://books.google.com/books?id=cqQX9RMPAegC&q=penis&f=false|archive-date=26 March 2014}} and Anatidae (ducks, geese and swans).{{cite book|author=MobileReference|title=The Illustrated Encyclopedia of European Birds: An Essential Guide to Birds of Europe|url=https://books.google.com/books?id=RgPTUkhiSmkC&q=penis|archive-url=https://web.archive.org/web/20140326174050/http://books.google.com/books?id=RgPTUkhiSmkC&q=penis&f=false|url-status=dead|archive-date=26 March 2014|access-date=5 December 2012|date=15 December 2009|publisher=MobileReference|isbn=978-1-60501-557-6}} The magpie goose in the family Anseranatidae also has a penis. A bird penis is different in structure from mammal penises, being an erectile expansion of the cloacal wall (in ducks) and being erected by lymph, not blood.{{cite book|author=Frank B. Gill|title=Ornithology|url=https://books.google.com/books?id=zM0tG5ApO0UC&q=penis&pg=PA414|access-date=5 December 2012|date=6 October 2006|publisher=Macmillan|isbn=978-0-7167-4983-7|pages=414–|url-status=live|archive-url=https://web.archive.org/web/20140107223055/http://books.google.com/books?id=zM0tG5ApO0UC&pg=PA414&q=penis&f=false|archive-date=7 January 2014}} It is usually partially feathered and in some species features spines and brush-like filaments, and in a flaccid state, curls up inside the cloaca.

{{anchor|Mammals}}

{{multiple image

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| image1 = Papio_hamadryas-adult_penis-Lisbon_07.JPG

| caption1 = Penis of a hamadryas baboon

| image2 = Caloocan Annual Tilbury Race 45.jpg

| caption2 = Penis of a horse

| image3 = Penis-cat.jpg

| caption3 = Penis of a cat

| image4 = Great Dane penis.jpg

| caption4 = Penis of a dog (Great Dane)

| image5 = Retreat (5543779030).jpg

| caption5 = Penis of a giraffe

}}

As with any other bodily attribute, the length and girth of the penis can be highly variable between mammals of different species.{{cite book|author=Tim Birkhead|title=Promiscuity: An Evolutionary History of Sperm Competition|url=https://books.google.com/books?id=3i4Q8SvohfEC&pg=PA102|access-date=23 July 2013|year=2000|publisher=Harvard University Press|isbn=978-0-674-00666-9|page=102|url-status=live|archive-url=https://web.archive.org/web/20140326175533/http://books.google.com/books?id=3i4Q8SvohfEC&pg=PA102#v=onepage&q=penis&f=false|archive-date=26 March 2014}}{{cite book|author1=Virginia Douglass Hayssen|author2=Ari Van Tienhoven|title=Asdell's Patterns of Mammalian Reproduction: A Compendium of Species-Specific Data|url=https://archive.org/details/asdellspatternso00hays|url-access=registration|access-date=23 July 2013|year=1993|publisher=Cornell University Press|isbn=978-0-8014-1753-5}} In many mammals, the penis is retracted into a prepuce when not erect. Mammals have either musculocavernous penises, which expand while erect, or fibroelastic penises, which become erect by straightening without expanding.{{Cite book |last1=Chenoweth |first1=Peter J. |url=https://books.google.com/books?id=3JtcEAAAQBAJ&dq=musculocavernous+fibroelastic+penis&pg=PA16 |title=Manual of Animal Andrology |last2=Lorton |first2=Steven P. |date=2022-02-03 |publisher=CABI |isbn=978-1-78924-350-5 |language=en}} Preputial glands are present in some prepuces.{{cite book|author=Marvalee H. Wake|title=Hyman's Comparative Vertebrate Anatomy|url=https://books.google.com/books?id=VKlWjdOkiMwC&pg=PA583|access-date=23 July 2013|date=15 September 1992|publisher=University of Chicago Press|isbn=978-0-226-87013-7|page=583|url-status=live|archive-url=https://web.archive.org/web/20131231143932/http://books.google.com/books?id=VKlWjdOkiMwC&pg=PA583#v=onepage&q=penis&f=false|archive-date=31 December 2013}}{{Cite book |last=Feldhamer |first=George A. |url=https://books.google.com/books?id=udCnKce9hfoC&pg=PA194 |title=Mammalogy: Adaptation, Diversity, Ecology |date=2007-09-07 |publisher=JHU Press |isbn=978-0-8018-8695-9 |language=en}} The perineum of testicond mammals (mammals without a scrotum) separates the anus and the penis.

Marsupials and placental mammals expel both urine and semen from the urethra through the penis. A bone called the baculum is present in most placentals but absent in humans, cattle and horses.

In mammals, the penis is divided into three parts:{{cite book|title=Functional Anatomy and Physiology of Domestic Animals|url=https://books.google.com/books?id=naSWWxJLcd0C&q=penis%20OR%20glans|date=2009-03-04|publisher=John Wiley & Sons|isbn=9780813814513|author=William O. Reece|url-status=live|archive-url=https://web.archive.org/web/20180320145847/https://books.google.com/books?id=naSWWxJLcd0C&q=penis%20OR%20glans&f=false|archive-date=2018-03-20}}

• Roots (crura): these begin at the caudal border of the pelvic ischial arch.
• Body: the part of the penis extending from the roots.
• Glans: the free end of the penis and where the urethra opens into in placentals. The penile glans is absent in chimpanzees and bonobos.{{cite book|last=Dixson|first=Alan F.|title= Sexual Selection and the Origins of Human Mating Systems|page=68|url=https://books.google.com/books?id=VRTniKE2liYC&pg=PA68|year=2009|publisher=John OUP Oxford|isbn=978-0-19156-973-9}}

The internal structures of the penis consist mainly of cavernous, erectile tissue, which is a collection of blood sinusoids separated by sheets of connective tissue (trabeculae).

Canine penises have a structure at the base called the bulbus glandis.{{cite book|author=Susan Long|title=Veterinary Genetics and Reproductive Physiology|url=https://books.google.com/books?id=Gre0VUZuhGYC|year=2006|publisher=Churchill Livingstone Elsevier|isbn=978-0-7506-8877-2|access-date=2013-11-08|url-status=live|archive-url=https://web.archive.org/web/20140326180538/http://books.google.com/books?id=Gre0VUZuhGYC&printsec=frontcover#v=onepage&q=bulbus%20glandis&f=false|archive-date=2014-03-26}}{{cite book|author=R. F. Ewer|title=The Carnivores|url=https://books.google.com/books?id=IETMd3-lSlkC&pg=PA116|access-date=23 July 2013|year=1998|publisher=Cornell University Press|isbn=978-0-8014-8493-3|page=116|url-status=live|archive-url=https://web.archive.org/web/20140326181627/http://books.google.com/books?id=IETMd3-lSlkC&pg=PA116#v=onepage&q=penis&f=false|archive-date=26 March 2014}} During copulation, the spotted hyena inserts his penis through the female's pseudo-penis instead of directly through the vagina, which is blocked by the false scrotum. The pseudo-penis and pseudo-scrotum, which are actually a masculinized vulva, closely resemble the male hyena's genitalia, but can be distinguished from the male by the female's greater thickness and more rounded glans.{{cite journal | last1 = Glickman | first1 = SE | last2 = Cunha | first2 = GR | last3 = Drea | first3 = CM | last4 = Conley | first4 = AJ | last5 = Place | first5 = NJ | year = 2006 | title = Mammalian sexual differentiation: lessons from the spotted hyena | url = http://courses.washington.edu/pbio509/Glickman_etal.pdf | journal = Trends Endocrinol Metab | volume = 17 | issue = 9| pages = 349–356 | doi = 10.1016/j.tem.2006.09.005 | pmid = 17010637 | s2cid = 18227659 | url-status = live | archive-url = https://web.archive.org/web/20130222022824/http://courses.washington.edu/pbio509/Glickman_etal.pdf | archive-date = 2013-02-22 }} {{anchor|Felidae}}Domestic cats have barbed penises, with about 120–150 one millimetre long backwards-pointing spines.{{Cite journal |last1=Aronson |first1=L. R. |last2=Cooper |first2=M. L. |title=Penile spines of the domestic cat: their endocrine-behavior relations |journal=Anat. Rec. |volume=157 |issue=1 |pages=71–8 |year=1967 |pmid=6030760 |doi=10.1002/ar.1091570111 |s2cid=13070242 |url=http://www.catcollection.org/files/PenileSpines.pdf |url-status=dead |archive-url=https://web.archive.org/web/20170620212227/http://www.catcollection.org/files/PenileSpines.pdf |archive-date=2017-06-20 }}

Marsupials usually have bifurcated penises{{Cite book |last1=Tyndale-Biscoe |first1=C. Hugh |url=https://books.google.com/books?id=HpjovN0vXW4C |title=Reproductive Physiology of Marsupials |last2=Renfree |first2=Marilyn |date=1987-01-30 |publisher=Cambridge University Press |isbn=978-0-521-33792-2 |language=en}} that are retracted into a preputial sheath in the male's urogenital sinus when not erect.{{Cite book |last1=Armati |first1=Patricia J. |url=https://books.google.com/books?id=x3S5v971Nk0C |title=Marsupials |last2=Dickman |first2=Chris R. |last3=Hume |first3=Ian D. |date=2006-08-17 |publisher=Cambridge University Press |isbn=978-1-139-45742-2 |language=en}} Monotremes and marsupial moles are the only mammals in which the penis is located inside the cloaca.Gadow, H. On the systematic position of Notoryctes typhlops. Proc. Zool. Soc. London 1892, 361–370 (1892).Riedelsheimer, B., Unterberger, P., Künzle, H. and U. Welsch. 2007. Histological study of the cloacal region and associated structures in the hedgehog tenrec Echinops telfairi. Mammalian Biology 72(6): 330-341.

File:Tupinambis teguixin (Linnaeus, 1758) (8184632011).jpg]]

Male turtles and crocodilians have a penis, while male specimens of the reptile order Squamata, which are snakes and lizards, have two paired organs called hemipenes. Tuataras must use their cloacae for reproduction.Lutz, Dick (2005), Tuatara: A Living Fossil, Salem, Oregon: DIMI PRESS, {{ISBN|0-931625-43-2}} Due to evolutionary convergence, turtle and mammal penises have a similar structure.{{cite journal | pmc=1810052 | year=2004 | last1=Kelly | first1=D. A. | title=Turtle and mammal penis designs are anatomically convergent | journal=Proceedings. Biological Sciences | volume=271 | issue=Suppl 5 | pages=S293–S295 | doi=10.1098/rsbl.2004.0161 | pmid=15503998 }}

In some fish, the gonopodium, andropodium, and claspers are intromittent organs (to introduce sperm into the female) developed from modified fins.{{Cite book |last=Ruschenberger |first=William Samuel Waithman |url=https://books.google.com/books?id=700AAAAAYAAJ |title=Elements of Herpetology, and of Ichthyology: Prepared for the Use of Schools and Colleges |date=1846 |publisher=Grigg & Elliot |pages=129–145 |language=en}}

{{Redirect|Female penis|the homologue to the penis in female amniotes|Clitoris}}

File:Callosobruchus analis penis.jpg]]

Harvestmen are the only male arachnids that have a penis.

In male insects, the structure analogous to a penis is known as an aedeagus. The male copulatory organ of various lower invertebrate animals is often called the cirrus.{{Cite encyclopedia |title=Penis {{!}} Description, Anatomy, & Physiology {{!}} Britannica |encyclopedia=Encyclopædia Britannica |date=January 2024 |url=https://www.britannica.com/science/penis |language=en}}

In 2010, entomologist Charles Linehard described a new genus of barkflies called Neotrogla. Species of this genus have sex-reversed genitalia: females have penis-like organs called gynosomes that are inserted into vagina-like openings of males during mating.{{cite journal|first1=Charles|last1=Lienhard|first2=Thais|last2=Oliveira do Carmo|first3=Rodrigo|last3=Lopes Ferreira|year=2010|url=http://biostor.org/reference/134593|title=A new genus of Sensitibillini from Brazilian caves (Psocodea: 'Psocoptera': Prionoglarididae)|journal=Revue suisse de Zoologie|volume=117|issue=4|pages=611–635|issn=0035-418X|url-status=live|archive-url=https://web.archive.org/web/20141103042552/http://biostor.org/reference/134593|archive-date=2014-11-03|doi=10.5962/bhl.part.117600|doi-access=free}} A similar female structure has also been described in the closely related Afrotrogla.Yoshizawa K, Ferreira R.L., Yao I, Lienhard C & Kamimura Y. "Independent origins of female penis and its coevolution with male vagina in cave insects (Psocodea: Prionoglarididae)". Biology Letters 14(11): [https://royalsocietypublishing.org/doi/full/10.1098/rsbl.2018.0533 doi.org/10.1098/rsbl.2018.0533] Scientists who study these insects have occasionally called the gynosome a "female penis"{{cite journal|last1=Yoshizawa|first1=Kazunori|last2=Ferreira|first2=Rodrigo L.|last3=Kamimura|first3=Yoshitaka|last4=Lienhard|first4=Charles|title=Female Penis, Male Vagina, and Their Correlated Evolution in a Cave Insect|journal=Current Biology|volume=24|issue=9|pages=1006–10|year=2014|issn=0960-9822|doi=10.1016/j.cub.2014.03.022|pmid=24746797|doi-access=free|bibcode=2014CBio...24.1006Y |hdl=2115/56857|hdl-access=free}}Yoshizawa K, Ferreira R.L., Lienhard C & Kamimura Y. (2019). "Why Did a Female Penis Evolve in a Small Group of Cave Insects?". BioEssays 41(6): [https://onlinelibrary.wiley.com/doi/abs/10.1002/bies.201900005 doi.org/10.1002/bies.201900005] and insisted to drop the definition of penis as "the male copulatory organ".Yoshizawa K, Ferreira R.L., Kamimura Y & Lienhard C. [https://www.biologiasubterranea.com.br/workspace/uploads/artigos/a-transgender-brazilian-cave-insect.pdf "A Transgender Brazilian Cave Insect"]. The Winnower 3/9/2014 Motivations for using the term "female penis" include that such a term "is easier to understand and much more eye-catching"Hollier J & Hollier A. (2020). [http://www.biologiasubterranea.com.br/workspace/uploads/artigos/a-transgender-brazilian-cave-insect.pdf "The retired taxonomist and the gynosome – the discovery of the female penis"]. Antenna 44(3): p. 122-125 and that the gynosome have "analogous features" with male penises. Meanwhile, critics have argued that it does not fit the intromittent organ definition of "a structure that enters the female genital tract and deposits sperm".Hayssen V. (2020). "Misconceptions about Conception and Other Fallacies: Historical Bias in Reproductive Biology". Integrative and Comparative Biology 60(3): p. 683-791: [https://academic.oup.com/icb/article/60/3/683/5836306 doi.org/10.1093/icb/icaa035]

{{Main|Pizzle}}

Pizzles are represented in heraldry, where the adjective pizzled (or vilené{{Cite book|last=Rietstap |first=J. B. |title=Armorial général; précédé d'un Dictionnaire des termes du blason |year=1884 |page=XXXI |publisher=G. B. van Goor zonen |quote=Vilené: se dit un animal qui a la marque du sexe d'un autre émail que le corps |url= https://archive.org/details/armorialgnralpr00rollgoog }}) indicates that part of an animate charge's anatomy, especially if coloured differently.

{{Div col|colwidth=15em}}

• Diphallia
• Fascinus
• Koteka
• Palpal bulb
• Stamen
• Testicle

{{Div col end}}

{{reflist|colwidth=30em}}

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{{refend}}

{{refbegin|30em}}

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{{refend}}

{{Wiktionary|penis}}

{{Commons|Penis}}

{{Commons category|Male genitalia in heraldry}}

• [http://www.kinseyinstitute.org/resources/bib-penis.html Kinsey Institute on the penis]

{{Authority control}}

Category:Animal male reproductive system

Category:Mammal male reproductive system

Category:Sex organs

Category:Urinary system