The original title of the essay was The Mad Folk of English Comedy and Tragedy down to 1642. It has been shortened for purposes of convenience, and the term Eliza bethan extended in order to take in a few plays which belong to the next two reigns. The term is, however, generally recognised to be an elastic one, and most of the plays dealt with fall easily within it. Much of the revision of this work has been carried out under pressure of other duties. I have been greatly helped in it by the criticisms and suggestions of Professor G. Moore Smith,by the constant help of Mr. N. G. Brett James, by some useful information given me by Mr. 0. L1. Bullock, and especially by the kindness Of my friend, Dr. J. Hamilton, who has read the essay through in manuscript from the point of view of the physician. Although I have not always taken up this standpoint in dealing with my subject, I have tried at all times to give it due consideration, for, as Ferdinand says in the Duchess of Malfi, Physicians are like kings: they brook no contradiction.