HYMEN, in anatomy, a membrane in general; but by it is usually understood the membrane which appears in the form of a crescent, and is situated at the entrance of the vagina. When this membrane is ruptured, it is shrivelled up, and forms the carunculæ myrtiformes. It naturally shrinks with years, and often disappears before the age of 20, so can be no proof of virginity.
In some infants this membrane so closes up the urethra, that the urine cannot be voided: in others, the urine passes, but when the menses flow, they cannot be discharged, because of the imperforated hymen.
When the mark of perforation cannot be seen, the cure is thought to be impracticable; but when the puncture
puncture of a lancet could not produce the desired effect, a trochar and canula hath succeeded, though a passage of four inches was perforated before the end was obtained.—In the memoirs of the Royal Academy of Sciences for 1756, we have an account of a conception without any perforation of the hymen.