This book is derived from my long-standing interest in the reproductive biology of vascular plants, in particular of the ferns and flowering plants. During the initial planning stages of this venture, the book was intended as a revision of my Experimental Embryogenesis in Vascular Plants (Academic Press) published in 1976, with the specific aim of describing how our present ideas in molecular and genetic biology apply to embryo development in vascular plants. After I wrote two or three chapters on angiosperm embryogenesis, I began to view the project essentially as a revision of my 1986 book, Embryogenesis in Angiosperms: A Developmental and Experimental Study (Cambridge University Press), and aborted the idea of covering embryogenesis of ferns and gymnosperms. Reflecting the perspective of current research, it began to dawn on me that molecular and genetic principles underlying embryo development in angiosperms have much in common with principles regulating the whole gamut of reproductive processes in flowering plants. This periodic reshaping and refining of the various drafts during the past five years has resulted in the present volume providing a synthetic review of molecular and cellular aspects of the familiar sequence in the reproductive biology of flowering plants, beginning with the flower and terminating with the embryo. It is thus a wholly new book and has very little to share with its predecessors.

My objective in writing this book is to explain the progress achieved toward a molecular understanding of the reproductive processes in angiosperms with particular emphasis on embryology.