4 THE AGE OF MAMMALS 



tive, so that there is always a true adaptive correlation, although not of 

 invariable association of certain kinds of organs, as Cuvier conceived it. 

 The law of correlation of tooth and foot structure may, therefore, be 

 restated as follows : — 



The feet, which are correlated chiefly with the limb and body 

 structure, and the teeth, which are correlated chiefly with the skull 

 and neck structure, diverge and evolve independently in adapta- 

 tion to securing food and to- eating food under different condi- 

 tions of life and in different environments. Each part evolves 

 directly to perform its own mechanical functions and purposes, yet 

 in such a manner that each subserves all the other parts.' 



Systematic Palceontology 



After the splendid osteological investigations of Cuvier had revealed 

 a new mammalian world of wonderful richness, his successors were bent 

 upon multiplying the diversity of this extinct creation, that is, adding 

 new species and genera, rather than on closely studying the osteology of 

 the fossil forms or adding new working principles to the science. In France 

 De Blainville was the one great generalizer up to the time of Gaudry. 

 Thus both in France and America facts accumulated more rapidly than 

 principles. Cuvier's chief contributions were to the Upper Eocene mam- 

 mals, to a few Miocene forms, and to many Pleistocene forms. His suc- 

 cessor, Henri Marie Ducrotay de Blainville (1778-1850), in his Osteo- 

 graphie des Mammiferes" (1839-1864) added to the knowledge of the 

 Basal and Lower Eocene fauna of France. Croizet and Jobert ^ described 

 (1828) the mammals of Perrier and Malbattu, Upper Pliocene. In the 

 middle of the century Paul Gervais (1816-1879) published his Zoologie 

 et Paleontologie Franqaises} In 1851 Edouard Lartet (1801-1870) 

 published his Notice sur la Colline de Sansan.^ Sansan is a rich 

 Middle Miocene deposit discovered by Lartet in 1834, explored for many 

 years, and finally monographed by Henri Filhol (1843-1907) in 1891.* 



' Cf. pp. 192, 193, of Osborn, The Rise of the Mammalia in North America. Amer. Jour. 

 Scl, Nov. and Dec, 1893. 



^ Ducrotay de Blainville, Osteographie ou Description Iconographique Comparee du 

 Squelette et du Syst^me Dentaire des Mammif^res Recents et Fossiles pour Servir de Base 

 k la Zoologie et k la Geologie. Paris, 1839-1864. 



^ Croizet et Jobert, Recherches sur les Ossemens fossiles du Departement du Puj'-do- 

 Dome. Paris, 1828. 



* Gervais, Zoologie et Paleontologie Frangaises. Nouvelles Recherches sur les Animaux 

 Vertebres dont on Trouve les Ossements Enfouis dans le Sol de la France et sur leur Comi^a- 

 raison avec Esp^ces Propres aux Autres Regions du Globe. Paris, 1859. 



* Lartet, Notice sur la Colline de Sansan, suivie d'une Recapitulation des Diverses Es- 

 p^ces d'Animaux Vertebres Fossiles Trouves soit a Sansan, soit dans d'Autres Gisements du 

 Terrain Tertiaire Miocene dans le Bassin Sous-Pyreneen. Auch, 1851. 



^ Filhol, Etude sur les Mammifdres Fossiles de Sansan. Ann. <Sc. Geol., XXI, 1, Art. 1. 

 Paris, 1891. 



