216 Lull — Development of Vertebrate Paleontology. 



441 titles, ranging over the fields of paleontology, — which 

 of course includes the greater number — geology, correla- 

 tion and paleogeography, evolutionary principles exem- 

 plified in the Mammalia, man, neurology and embry- 

 ology, biographies, and the theory of education. 



In paleontology, Osborn 's researches have been largely 

 with the Eeptilia and Mammalia, partly morphological, 

 but also taxonomic and evolutional. Faunistic studies 

 have also been made of the mammals. Of his published 

 volumes the most important are, first, the Age of Mam- 

 mals (1910), in which he treats not of evolutionary series 

 of phylogenies, but of faunas and their origin, migra- 

 tions, and extinctions, and of the correlation of Old and 

 New World Tertiary deposits and their contents. Men 

 of the Old Stone Age (1916) is an exhaustive treatise and 

 is the first full and authoritative American presentation 

 of what has been discovered up to the present time 

 throughout the world in regard to human prehistory. In 

 his latest volume, The Origin and Evolution of Life 

 (1917), Osborn presents a new energy conception of evo- 

 lution and heredity as against the prevailing matter and 

 form conceptions. In this volume there is summed up 

 the whole story of the origin and evolution of life on 

 earth up to the appearance of man. This last book is 

 novel in its conceptions, but it is too early as yet to judge 

 of the acceptance of Osborn's theses by his fellow work- 

 ers in science. 



Since the death of Professor Marsh, Osborn has served 

 as vertebrate paleontologist to the United States Geolog- 

 ical Survey, and has in charge the carrying through to 

 completion of the many monographs proposed by his dis- 

 tinguished predecessor. One of these, that on the horned 

 dinosaurs, has been completed by Hatcher and Lull 

 (1907), another on the stegosaurian dinosaurs has been 

 carried forward by C. W. Gilmore of the United States 

 National Museum, while under Osborn's own hand are 

 the memoirs on the titanotheres (aided by W. K. Greg- 

 ory), the horses, and the sauropod dinosaurs. Of these, 

 the first, when it shall have been completed, promises to 

 be the most monumental and exhaustive study of a group 

 of fossil organisms ever undertaken. 



As a leader in science, a teacher and administrator, 

 Professor Osborn's rank is high among the leading verte- 

 bratists. He is remarkably successful in his choice of 



