Of the Arrangement and Elements of Sentences, addressed to Philip, three books. Of the Elements of Speech, addressed to Nicias, one book. Of the Relative Term, one book. Third series : Against Those who reject Division, two books. On Ambiguous Forms of Speech, addressed to Apollas, four books. On Figurative Ambiguities, one book. Of Ambiguity in the Moods of the Hypothetical Syllogism, two books. A Reply to the Work of Panthoides on Ambiguities, two books. Introduction to the Study of Ambiguities, five books. Epitome of the Work on Ambiguities, addressed to Epicrates, one book. Materials collected for the Introduction to the Study of Ambiguities, two books. IV. Logic as concerned with syllogisms and moods. First series : Handbook of Arguments and Moods, addressed to Dioscurides, five books. Of Syllogisms, three books. Of the Construction of Moods, addressed to Stesagoras, two books. Comparison of the Judgements expressed in the Moods, one book. Of Reciprocal and Hypothetical Syllogisms, one book. To Agathon,or Of the Problems that remain, one book. On the Question what Premisses are capable of demonstrating a given Conclusion with the Aid of one or more Subsidiary Premisses, one book. vol. ii x 305