More than ninety years ago, Stillmark (1888) discovered that castor-bean extracts caused agglutination of human red cells. Boyd and Shapeleigh (1954) invented the term “lectin” (from legere, to select) for this group of plant proteins which are capable of hemagglutination. It soon became apparent that lectins are carbohydrate-binding proteins. Modern nomenclature defines lectins as carbohydrate-binding proteins which are not immunoglobulins or enzymes.