The mammals were, perhaps, the most prolific source of paleontological research during the nineteenth century, for, as Zittel has said, Cuvier’s famous investigations on the fossil bones, mentioned above, not only contain the principles of comparative osteology, but also show in a manner which has never been surpassed how fossil vertebrates ought to be studied, and what are the broad inductions which may be drawn from a series of methodical observations. Such was Cuvier’s influence that until Darwin began to interest himself in mammalian paleontology the study of these forms was conducted entirely along the lines indicated by the French savant. This was seen in a large work, Osteology of Recent and Fossil Mammalia, by De Blainville, which, although not up to the standard set by the master, is nevertheless a notable contribution, as was also the Osteology prepared by Pander and D’Alton. A summary of the knowledge of the fossil Mammalia up to the year 1847 is contained in Giebel’s Fauna der Vorwelt, and Lydekker has done for the mammals in the British Museum what Smith Woodward did for the fishes, producing vastly more than the mere catalogue which the title implies. The first work wherein the fossil mammals were treated genealogically was Gaudry’s Enchaînements du Monde Animal, written in 1878. Other work on the fossil Mammalia was done by Kaup, who described those from the Mainz basin and from Epplesheim near Worms whence came one of the most famous of prehistoric horses, the _Hipparion_; this horse, together with the remarkable proboscidean _Dinotherium_, was described by Von Meyer. One of the most remarkable discoveries, ranking in importance, perhaps, next to Montmartre, was that of the Pliocene fauna of Pikermi near Athens, Greece, first made known through the publications of A. Wagner of Munich and later, and much more extensively, through that of Gaudry (1862–1867). H. von Meyer was Germany’s best authority on fossil Mammalia. After his death the work was carried on by Quenstedt, Oscar Fraas, Schlosser, Koken, and Pohlig, among others. In France, rich deposits of fossil mammals were discovered in the Department of Puy-de-Dôme, the Rhone basin, Sansan, Quercy, and near Rheims. These were described by a number of writers, notably Croizet and Jobert, Pomel, Lartet, Filhol, and Lemoine.