This study is a review of the English literature on the subject. 84 cases were studied, including true hermaphrodites, pseudo-hermaphrodites and ? true hermaphrodites: only case reports that indicated libido status after puberty, sexual behaviour, proof of type of gonadal tissue and a description of the external and secondary sex organs were included. Even though most pseudo-hermaphrodites are male pseudo-hermaphrodites, those brought up as males take a male rôle almost exclusively and a majority of those brought up as females take a female rôle; 80 per cent. of those pseudo-hermaphrodites who had been brought up as females and took the female sex rô were actually male pseudo-hermaphrodites. A decided majority of ? true hermaphrodites brought up as females assume a female sex rôle and the over-whelming majority of those brought up as males take a male rôle. A majority of the true hermaphrodites brought up as females took the female sex rôle and an overwhelming majority of those brought up as males took the male rôle; 6 per