The author concludes from her clinical experience that certain occurrences in the girl-baby's life play a more important rôle in helping her to switch over from mother to father object-choice than has so far been appreciated. Not infrequently she finds herself attractive to members of the opposite sex and able to produce reactions in them. Thus exploration of a brother's penis may result in its erection. These experiences awaken the phantasy that the penis and the person owning it belong to her because she can do things to them. This helps to detach her from her mother and to launch her on the search to make the penis her own and take it into herself, as she does later in coitus and pregnancy. The success or failure of her early experiments with men and boys exerts a very important influence upon her later development. In adult life the attractive woman who is aware of her power over men and who fulfils her sexual-reproductive rôles is seldom 'castrated' or burdened with feelings of inferiority.