First published in 1895. According to the Preface: "Notwithstanding the immense number of books, dissertations, and papers which have been written on pictorial and decorative art, I venture to add one more to their number. I profess to be neither an artist nor an art critic, but simply a biologist who has had his attention turned to the subject of decorative art. One of my objects is to show that delineations have an individuality and a life-history which can be studied quite irrespectively of their artistic merit."