Should the selection be made from the Catalogue, it will be advisable to give the Author permission to change any one of the selected Plates for any other illustrating the same action, if, in his judgment, the substituted Plate illustrates that action with a better model, or in a more perfect manner than the one selected. With regard to the selection of Plates, however, it has been found by experience that unless any special subject or plate is required it will be more satisfactory to the subscriber if he gives the Author GENERAL INSTRUCTIONS as to the CLASS of subjects desired and to leave the SPECIFIC selection to him. Many of the large Libraries and Art or Science Institutions in America and in Europe have subscribed for, and have now in their possession, a complete series of the seven hundred and eighty-one Plates, the subscription price for which is FIVE HUNDRED DOLLARS in the United States, ONE HUNDRED GUINEAS in Great Britain for the complete series, in eight full AMERICAN-RUSSIA LEATHER PORTFOLIOS, or if bound in eleven volumes, each plate _hinged_, full American-Russia leather, FIVE HUNDRED AND FIFTY DOLLARS in the United States, ONE HUNDRED AND TEN GUINEAS in Great Britain; or its equivalent for any city in Central or Western Europe. Subscribers who wish to make use of these Plates for the promotion or diffusion of knowledge, or for artistic or scientific purposes, will be afforded facilities for acquiring working copies by special arrangement with the Author. The investigations of the Author are so well known; and so generally recognized as affording the only basis of truthful interpretation or accurate criticism of Animal Movement, that it is perhaps scarcely necessary to quote from the many elaborate reviews of "Animal Locomotion," which have been published in the American, English, French, and German Scientific, Artistic, and other Journals. A few extracts therefrom are however given in Appendix A. For the value of the present work to the general student of Nature and the lover of Art, no less than to the Artist and the Archæologist, the Physiologist and the Anatomist, it is with much pride and gratitude that he refers to the annexed list of some of his subscribers. SUBSCRIBERS. The general or departmental Libraries of the following UNIVERSITIES. Amsterdam Andrews, St. Basel Berlin Bern Bologna Bonn Breslau Bruxelles Edinburgh Erlangen Freiburg Genève Genova Glasgow Göttingen Griefswald Hallé Heidelberg Innsbrück Jena Kiel Königsberg Leiden Leipzig Liège Louvain München Napoli Oxford Padova Pisa Prag Roma Rostock Strassburg Torino Tübingen Utrecht Wien Würzberg Zürich IMPERIAL, NATIONAL, OR ROYAL ACADEMIES OF FINE ARTS.