Even when children learn that babies come out of the mother's body this knowledge often remains very vague and inaccurate. It very commonly happens, for instance, in all civilized countries that the navel is regarded as the baby's point of exit from the body. This is a natural conclusion, since the navel is seemingly a channel into the body, and a channel for which there is no obvious use, while the pudendal cleft would not suggest itself to girls (and still less to boys) as the gate of birth, since it already appears to be monopolized by the urinary excretion. This belief concerning the navel is sometimes preserved through the whole period of adolescence, especially in girls of the so-called educated class, who are too well-bred to discuss the matter with their married friends, and believe indeed that they are already sufficiently well informed. At this age the belief may not be altogether harmless, in so far as it leads to the real gate of sex being left unguarded. In Elsass where girls commonly believe, and are taught, that babies come through the navel, popular folk-tales are current (_Anthropophyteia_, vol. iii, p. 89) which represent the mistakes resulting from this belief as leading to the loss of virginity. Freud, who believes that children give little credit to the stork fable and similar stories invented for their mystification, has made an interesting psychological investigation into the real theories which children themselves, as the result of observation and thought, reach concerning the sexual facts of life (S. Freud, "Ueber Infantile Sexualtheorien," _Sexual-Probleme_, Dec., 1908). Such theories, he remarks, correspond to the brilliant, but defective hypotheses which primitive peoples arrive at concerning the nature and origin of the world. There are three theories, which, as Freud quite truly concludes, are very commonly formed by children. The first, and the most widely disseminated, is that there is no real anatomical difference between boys and girls; if the boy notices that his little sister has no obvious penis he even concludes that it is because she is too young, and the little girl herself takes the same view. The fact that in early life the clitoris is relatively larger and more penis-like helps to confirm this view which Freud connects with the tendency in later life to erotic dream of women furnished with a penis. This theory, as Freud also remarks, favors the growth of homosexuality when its germs are present. The second theory is the fæcal theory of the origin of babies. The child, who perhaps thinks his mother has a penis, and is in any case ignorant of the vagina, concludes that the baby is brought into the world by an action analogous to the action of the bowels. The third theory, which is perhaps less