It is in this aspect that they are of the most interest in the history of English tragedy. They are not a freak variation but a species lineally related to those which precede and follow. They carry the restriction and conventionalization of the material of tragedy much farther than did the plays of Shirley and his contemporaries; and, somewhat before Racine, they confine the main course of tragedy to sentimental love. Though their main innovation, the employment of rhyme, did not prevail, and though their changes in technic were rejected by many later Restoration dramatists, yet they were a powerful force in habituating the theatre to the structure and methods of French tragedy and in promoting the triumph of these methods in the next century. They also mark a further change in the conception of the field and functions of tragedy. The result of developments from tragicomedy rather than from tragedy, they exhibit a blending of the two forms and a redivision along new lines. Before the Restoration, nearly all tragedies had presented a mixture of comedy or of farce. Tragicomedy had been distinguished from tragedy not by the presence of comedy but by the fact that its leading persons were brought near to death yet saved for a happy ending. Moreover, tragicomedies as a class developed along the lines of the Beaumont-Fletcher romances. The heroic plays inherited the traits of this class and also to some extent the happy endings. In some, as Orrery's "Henry V," there is no suffering and everything turns out well; in others, as Orrery's later plays, there is bloodshed enough; but in nearly all death is visited only on the evil; the heroic are married. All plays with heroic themes, however, were called tragedies. There was no hint of heroic comedy as in France. The distinction between tragedy and comedy, which the Restoration drama drew much more closely than the Elizabethan, came to depend less on the presence of deaths or of an unhappy ending, and more on the nature of the material and form. After the decline of the heroic plays, tragedy returned, as we shall see, to bloodshed, deaths, and horrors, but meantime the heroic plays had emphasized as essential certain elements that long continued their ascendency in both critical and popular views of tragedy. Henceforth every one associated with tragedy heroic actions, illustrious persons, verse, whether rhymed or blank, a love story, and an inflated diction. The curious heroic rant, indeed, supplied a vocabulary and a manner that lasted long after the jingle of the rhyming couplets had been abandoned. Its "furies," "vows," "chains," "transports," "ecstasies," and "Etnas burning within the breast" remained the language of despairing innocence and palpitating passion. Tragic became almost synonymous with artificial and inflated.