Hemipenis

A hemipenis (pl.: hemipenes) is one of a pair of intromittent organs of male squamates (snakes and lizards).^[1]^[2]^[3] Hemipenes are usually held inverted within the body, and are everted for reproduction via erectile tissue, much like that in the human penis. They come in a variety of shapes, depending on species, with ornamentation such as spikes.

^ "Hemipenes".
^ "Male reproductive behaviour of Naja oxiana (Eichwald, 1831) in captivity, with a case of unilateral hemipenile prolapse". Herpetology Notes. 2018. (Full text via https://www.biotaxa.org/hn/article/view/34541/37750.)
^ Holmes MM, Putz O, Crews D, Wade J (April 2005). "Normally occurring intersexuality and testosterone induced plasticity in the copulatory system of adult leopard geckos". Horm Behav. 47 (4): 439–45. doi:10.1016/j.yhbeh.2004.11.020. PMID 15777809. S2CID 18482667.

[1] "Hemipenes".

[2] "Male reproductive behaviour of Naja oxiana (Eichwald, 1831) in captivity, with a case of unilateral hemipenile prolapse". Herpetology Notes. 2018. (Full text via https://www.biotaxa.org/hn/article/view/34541/37750.)

[3] Holmes MM, Putz O, Crews D, Wade J (April 2005). "Normally occurring intersexuality and testosterone induced plasticity in the copulatory system of adult leopard geckos". Horm Behav. 47 (4): 439–45. doi:10.1016/j.yhbeh.2004.11.020. PMID 15777809. S2CID 18482667.

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