Penile sheath

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Almost all mammal penises have foreskins,[citation needed] although in non-human cases the foreskin is usually a sheath (sometimes called the preputial sheath[1] or penile sheath[2]) into which the whole penis is retracted. In koalas, the foreskin contains naturally occurring bacteria that play an important role in fertilization.[3] Only monotremes (the platypus and the echidna) lack foreskins.[4]

During musth, a male elephant may urinate with the penis still in the sheath, which causes the urine to spray on the hind legs.[5]

Male dogs have a conspicuous penis sheath.[6]

In stallions, the retractor penis muscle contracts to retract the stallion's penis into the sheath and relaxes to allow the penis to extend from the sheath.[7]

The penis sheath of a male axis deer is elongated and urine-stained. When rubbing trees with their horns, chital stags sometimes move the penis back and forth rapidly inside its sheath.[8] Male bison and fallow deer have tufts of fur at the end of their penis sheaths.[9]

See also[edit]

References[edit]

  1. ^ Edward C. Feldman (2004). Canine and feline endocrinology and reproduction. Elsevier Health Sciences. pp. 934–. ISBN 978-0-7216-9315-6. Retrieved 25 April 2013. 
  2. ^ The behavior guide to African mammals: including hoofed mammals, carnivores, primates. University of California Press. 1991. pp. 116–. ISBN 978-0-520-08085-0. Retrieved 25 April 2013. 
  3. ^ "UQ researchers unlock another koala secret". Uq.edu.au. 2001-05-09. Retrieved 2012-07-16. 
  4. ^ "Reproductive System". MSN Encarta. Seattle, WA, USA: Microsoft Corporation. 2006. Archived from the original on 2009-10-31. 
  5. ^ Sukumar, pp. 100–08.
  6. ^ George B. Schaller (15 October 2009). The Serengeti Lion: A Study of Predator-Prey Relations. University of Chicago Press. pp. 329–. ISBN 978-0-226-73660-0. Retrieved 10 February 2013. 
  7. ^ "The Stallion: Breeding Soundness Examination & Reproductive Anatomy". University of Wisconsin-Madison. Archived from the original on 2007-07-16. Retrieved 7 July 2007. 
  8. ^ Valerius Geist (1998). Deer of the World: Their Evolution, Behaviour and Ecology. Stackpole Books. ISBN 978-0-8117-0496-0. Retrieved 11 May 2013. 
  9. ^ Fiona Reid (15 November 2006). Peterson Field Guide to Mammals of North America: Fourth Edition. Houghton Mifflin Harcourt. ISBN 978-0-547-34553-6. Retrieved 11 May 2013. 

Further reading[edit]