This volume contains the remarkable PhD thesis submitted by Crozier in 1972, and for which his external examiner was J.H. Prynne-whose comments on the thesis are also included here, as an afterword. My intention in writing this thesis has been to cast some light on the prima facie case that free verse, in abandoning the exercise of metre, has abandoned that principle of restraint upon which the creation of artistic form depends. This point of view contrasts with a general contention on the part of the exponents of free verse that their works possess form which is not only unique but which also bears an immediate relation to the significance of the work, a relationship felt to be ‘musical’, although not in any directly analogical sense.