Because Wright is considered one of the authorities today in the field of color, this book warrants the attention of all interested in color physiology. The book describes and summarizes with unusual completeness the results of most of the recent experimental research, and points out the theoretical implications of those results with the emphasis placed on the physiology involved. Although the author describes the experimental works of others, he devotes most of the book to his own research or to that of the Imperial College of Science and Technology in London. The book is written in a technical lanuage.