Perhaps if Beaumont had lived, the two might have advanced to maturer and worthier achievement, but Fletcher's work alone rather displays the superficialities and artificialities of the collaboration. His amazing cleverness appears in every scene, but he evidently wrote more and more for immediate success, and relied more and more on his readinesss of wit and invention to take the place of earnest and serious purpose. The long series of plays in which he had at least a considerable share, range in kind from comedies of manners to tragedies of blood and revenge, but practically all may be described as romantic drama, having, that is, strange improbable events, foreign and remote scenes, variety and surprise in action, and love as the central motive. His sense of dramatic value in theme or incident was constantly alert, and in Spanish stories, especially the "Novellas Exemplares" of Cervantes, he found mazes of complicated action which exactly suited his fancy, and which he managed with adroit dramaturgy. The Spanish influence is more noticeable in the comedies than in the more serious plays; but, whatever the theme or the source, Fletcher added bustle and excitement. The distinctions between tragedy, comedy, tragicomedy, and romantic comedy often become barely discernible. The material and treatment are similar. Tragic situations occur in comedies as well as tragedies, and in either case, though finely conceived and admirably expressed, are yet always directed by the desire for surprise and thrills. The tragicomedies conform most closely to the conventionalities and repetitions of the heroic romances, though they exhibit abundant originality of invention. Through their example, romantic and melodramatic tragicomedy became perhaps the most popular and characteristic dramatic species of the reign of Charles I, and a direct progenitor of the heroic plays of the Restoration.