Studies have shown evidence of female ejaculation in between 10 and 40% of female orgasms. hypothesis that ejaculation can occur in all (or most) cases -- thus, those percentages would correspond to those women who do notice their ejaculation. female ejaculation would be a substance with some similarities to male semen in its composition, produced by the paraurethral glands or Skene's glands, often called "female prostate" for its similitude in placement, structure and, given the discovery of female ejaculation, function, with the male prostate, the responsible of the production of semen. More noticeably in women -- but also in men -- these glands have also a function of sexual stimulation. the so called "vaginal orgasm" (as opposed to "clitoral orgasm", physiological structure of the famous G-spot or Gräfenberg spot, the location on the vagina anterior wall which would have sensitivit y to sexual stimulation. either by a penis, finger, etc. -- the glands in touch with it are those that experiment the stimulation. Thus, the female ejaculation is more likely to occur when stimulating the G-spot. The website The-clitoris.com "Dedicated to a Woman's Sexual Pleasure & Health", publishes excellent diagrams on how to stimulate this area and showing explanations of the issue in it -- at their page "The Female Prostate, Female Ejaculation, and The G-Spot"