In oviparous animals (those that lay eggs), the passage from the ovaries to the outside of the body is known as the oviduct. The eggs travel along the oviduct. The oviduct in birds is divided in several parts:

• Infundibulum (formation of Chalazae, place of fertilisation)
• Magnum (formation of egg white)
• Isthmus (formation of the shell membrane)
• Shell Gland (formation of egg shell)
• Vagina (formation of cuticula)

In mammals, which may have evolved from reptiles, the oviduct turned into the Fallopian tubes, the uterus and the vagina. The eggs do not travel all the way, but stay in the uterus. In these animals, the term oviduct should not be used. Birds do not have uterus, the uterus is generally a mammalian characteristic. Birds instead have the 'shell gland' where the calcium carbonate (shell) is added.

Reproductive system

Legedarm | 輸卵管 | Oviduto