Throughout The Chronicles of Narnia the humans are referred to as "Son of Adam" for a male, and "Daughter of Eve" for a female. I'm assuming that the characters in Narnia don't think that females only descend from a female but not a male, and males only descend from a male but not a female. I.e. technically, a male would be a son of Adam and a son of Eve; likewise, a female would be a daughter of Eve and a daughter of Adam.
If this is indeed correct, is there a reason why they always refer to males as "Son of Adam" and not "Son of Eve" or "Son of Adam and Eve"? And, similarly, is there a reason why they always refer to females as "Daughter of Eve" and not "Daughter of Adam" or "Daughter of Adam and Eve"?