Fig. 2From: A comprehensive comparison of sex-inducing activity in asexual worms of the planarian Dugesia ryukyuensis: the crucial sex-inducing substance appears to be present in yolk glands in TricladidaProcedure for the fractionation of sexually mature worms. See the text for experimental details. Fr., fraction. Three fractions and a layer used for the bioassay are highlighted in the boxBack to article page