PREFACE.
In my work on "Cave-hunting," published in 1874, I endeavoured to clear the way for the present enquiry into primæval man, his growth in culture, his conditions of life, and his relation to history; and I found it necessary to treat of cave-exploration in detail, before I could venture to grapple with the difficulties inherent in a work which treats of the borderland of geology, archæology, and history. In dealing with them, I have to acknowledge my debt to the writings of Sir Charles Lyell, Sir John Lubbock, Mr. John Evans, Dr. Thurnam, and Mr. Franks in this country; to Professors Gaudry, Steenstrup, Capellini, and Drs. Broca, Virchow, Wiberg, Rütimeyer, Forsyth Major on the Continent, as well as to many contributors to the scientific periodicals of France, Switzerland, Italy, and Germany, and more especially to the valuable memoirs in the Comptes Rendus du Congrès International d'Anthropologie et d'Archéologie Préhistoriques. I have also used the materials accumulated in some of my own Essays published in the Edinburgh and Fortnightly Reviews, and in the Quarterly Journal of the Geological Society. I have attempted more particu-
