There are many recent works on the topic of light and plant growth. These have not only been written by experts, but are also, in the main, written for experts (or, at least, for those who already have a fair understanding of the subject). This book has its origins in a six-week course in plant photophysiology, and its aim is to provide an introduction to the subject at an advanced undergraduate level. The imagined audience is simply a student who has asked the questions: In what ways does light affect plant growth, and how does it do it? The book is limited to aspects of photomorphogenesis. Photo- synthesis is only considered where its pigments impinge on photo- morphogenic investigations, or where its processes provide illustrative examples of particular interactions between light and biological material. Chapter 1 gives a general account of the various ways in which light affects plant development, and introduces topics which are subsequently covered in greater detail. In all the chapters, are special topic 'boxes', consisting of squared-off sections of text. These are simply devices for presenting explanatory background material, or material that I myself find particularly intriguing.