Female genitals. 1866 illustration showing the blood supply (blue lines) and anatomy of the external female genitals that make up the vulva. Fig. I: labia (outer left and right), clitoris (long, upper centre), vestibular bulbs (clitoral bulbs, purple, centre left and right), opening of the urethra (circle, centre), the opening of the vagina (introitus, dark, lower centre). Fig. II: clitoris (top, centre), vestibular bulbs (blue), constrictor muscle of the vagina (brown). Fig. III: section through the constrictor muscle of the vagina.