For the historian this period offers less difficulties than the preceding ones. After 1610 comparatively few plays of importance are non-extant, and few of the extant plays are anonymous. The bulk of the important plays was produced by a few dramatists, who dominated the theatres and whose careers determined the drama's development. After examining the revenge plays which about 1612 gave a further extension to that species, and the heroic romances of the Beaumont-Fletcher collaboration, which were produced within a few years before that date, we may trace the succeeding developments of tragedy mainly in the work of Fletcher, Massinger, Middleton, Ford, and Shirley. The main line of the development of the revenge tragedy is represented by Tourneur's "Revenger's Tragedy," the anonymous "Second Maiden's Tragedy," and Webster's "White Devil" and "Duchess of Malfi." The four plays may be said to constitute a new species whose differences from the old type seem clearly unconnected with Shakespeare's "Hamlet" but directly traceable to Marston's plays, especially his "Malcontent." Revenge is no longer the main motive but is a subsidiary element in complicated stories of revolting lust and depravity. Tragedy has become the representation of vice and sin, with a proneness for their foulest entanglements. In one play a brother plays the part of pandar to his sister; in another a father to his daughter; and in a third a mother to her daughter. Nor is revenge, even in its subordinate position, the simple blood-for-blood requital that it is in Kyd. It may be for various causes beside murder; it is born of malice rather than duty; it may share in the moral turpitude of the rest of the action. The ghost no longer directs the course of revenge, and may disappear entirely. In "The Revenger's Tragedy" the skull of the betrothed, as the skeleton in "Hoffman," takes the place of the apparition; and in other plays the duties of the ghost are minimized or farmed out among various supernatural agents, two female ghosts appearing. Hesitation on the part of the avenger does not appear. Indeed, his entire character has changed. He may be a villain, as in "Hoffman," or the villain's accomplice, or one of Marston's "malcontents," or a combination of these parts. The other leading elements in the Kydian type are preserved. Insanity of various forms, real and pretended, is prominent. Intrigue of a complicated kind abounds, but is often dependent, after the fashion of current comedy, largely on improbable disguises. Deaths are as frequent as ever and more horrible. Much of the old stage effect reappears, as in the masques, funerals, ghosts, and exhibition of dead bodies, but there is a great increase in the number and ingenuity of melodramatic sensations. Each play is a chamber of horrors. In one, a wife dies from kissing the poisoned portrait of her husband; in another, the lustful king sucks poison from the jaw of a skull; and in a third, from the