Female seaweed receptacle. Light micrograph of a section through a receptacle from female bladderwrack (Fucus Vesiculosus) brown algae, showing the conceptacles (round) that contain the female reproductive organs (oogonia). The interior of the conceptacles is lined with hairs (paraphyses), the tips of which bear the oogonia. Male reproductive structures released from male receptacles are chemotactically attracted to the conceptacles of female seaweeds to fertilise them. Magnification: x7 when printed 10 centimetres wide.