PRESENT PROBLEMS 585 



paleontological progress has been the revelation of what was taking 

 place in Africa at the same time (Andrews x and Beadnell). This dis- 

 covery came with its quota of unthought-of forms, also with the 

 representatives of three orders which it had been prophesied 2 would 

 be found there, namely, the Proboscidea (elephants and mastodons), 

 the Sirenia (manatees and dugongs), and the Hyracoidea (conies). 

 The basis of this prophecy was the anomalous fact that these animals 

 suddenly appeared in Europe in the Miocene and Pliocene fully 

 formed and without any ancestral bearings; it was certain that they 

 had evolved somewhere, and Africa seemed the most probable home, 

 rather than the currently accepted unknown regions of Asia. Thus 

 by a sudden bound paleontology gains the early Tertiary pedigree 

 of the elephants and of two if not three other orders. 



Africa in the early Tertiary, whether from the absence of land con- 

 nections or from climatic barriers, was a very independent zoological 

 region. 2 Some predatory Cretaceous mammals (Creodonta or primi- 

 tive carnivores) found their way in there, also certain peculiar 

 artiodactyls (Hyopotamids). Here also were two remarkable types 

 of mammals (Arsinoitherium, Baryiherium) which have no known 

 affinities elsewhere, as well as the extremely aberrant Cetaceans or 

 Zeuglodonts. 



The Outlook 



From all these continents we have, therefore, finally gathered the 

 main history during the Tertiary period of eighteen orders of mam- 

 mals. We have still to solve the origin of the cetaceans or whales, 

 still to connect many of these orders which we call "modern" with 

 their sources in the basal Eocene and Upper Cretaceous, still to 

 follow the routes of travel which theytook from continent to contin- 

 ent. Encouraged by the prodigious progress of the past twenty-five 

 years, we are confident that twenty-five years more will see all the 

 present problems of history solved, and judging by past experience 

 we may look for the addition of as many new and no less important 

 ones. 



1 C. W. Andrews, in Geological Magazine for 1900, 1901, 1902, 1903, 1904, in 

 Annals and Magazine of Natural History, 1903, p. 115; in Proceedings of the 

 Zoological Society, London, 1902, p. 228; in Proceedings of the Royal Society, 

 vol. 71, p. 443; in Philosophical Transactions, ser. B, vol. 196, 1903, p. 99; in 

 Publications of the Survey Department, Cairo, Egypt. 



2 H. F. Osborn, The Geological and Faunal Relations of Europe and America . . . 

 and the Theory of the Successive Invasions of an African Fauna, Science, N. S. vol. 

 xi, no. 276, pp. 561-574, April 13, 1900. 



