[ **up: [[Reproduction and sex]]** ] --- # Intromission > Intromission is a step of sexual reproduction that involves the insertion of a male intromittent organ into the cavity of a female reproductive organ to facilitate insemination and internal fertilization.[^1] [^1]: Andrew M. Holub & Todd K. Shackelford (eds.), ‘Intromission’, *Encyclopaedia of Animal Cognition and Behavior* (Cham, Switzerland: Springer, 2022), pp. 3671–3673. https://doi.org/10.1007/978-3-319-55065-7_346.