Since antiquity, molluscs — in particular the nautilus — have been associated with Aphrodite, the goddess of love, as a symbol of the f. emale pudenda, sexual desire and aphrodisiacs. Although the female paper nautilus forms a shell, the male, as shown in this nineteenth-century lithograph, does not; to fertilize the female, one of the tentacles of the male separates from its body and swims towards her as a giant penis. The mollusc is one of several animals that have sneaked into Christian Ratsch's Plants of Love (Ten Speed Press, $19.95, pbk), a leisurely, visually enticing romp through the history, botany, chemistry, pharmacology and identification of various aphrodisiac plants. User instructions are also included. Caveat emptor