Reproductive system
Even-toed ungulates

The penises of even-toed ungulates have an S-shape at rest and lie in a pocket under the skin on the belly. The corpora cavernosa are only slightly developed; and an erection mainly causes this curvature to extend, which leads to an extension, but not a thickening, of the penis. Cetaceans have similar penises. In some even-toed ungulates, the penis contains a structure called the urethral process.
combination:two_responses