THE ADVANCEMENT OP SCIENCE. ^^ 



over every part of the globe. We have the most pregnant proof of the impor- 

 tance of PaljBontology in rectifying and expanding ideas deduced from recent 

 ssoology of the geographical limits of particular forms of animals, by the results 

 of its application to the proboscidian or elephantine family. But such retrospec- 

 tive views of life in remote periods, in many important instances, confirm the 

 zoologists deductions of the originally restricted range of particular forms of 

 mammalian life. The sum of all the evidence from the fossil world in Australia 

 proves its mammalian population to have been essentially the same in pleisto- 

 cene, if not pliocene times, as now ; only represented, as the Edentate mammals 

 in South America were then represented b}' more numerous genera, and much 

 more gigantic species, than now exist. But Geology has revealed more important 

 and unexpected facts relative to the marsupial type of quadrupeds. In the mio- 

 cene and eocene tertiary deposits, marsupial fossils of the American genus Didel- 

 phys have been found, both in France and England ; and they are associated with 

 Tapii's like that of America, In a more ancient geological period remains of 

 marsupials, some insectivorous, as Spalacotheriutn and Triconodon, others with 

 teeth like the peculiar premolars in the Australian genus Hypsipromnus, have 

 been found in the upper oolite of the Isle of Purbeck. In the lower oolite at 

 Stonesfield, Oxfordshire, marsupial remains have been found having their nearest 

 living representatives in the Australian genera Myrmecobius and Dasyurus. Thus 

 it would seem, that the deeper we penetrate the earth, or, in other words, the fur- 

 ther we recede tn time, the more completely are we absolved from the present 

 laws of geographical distribution. In comparing the mammalian fossils found in 

 British pleistocene and pliocene beds, we have often to travel to Asia or Africa for 

 their homologues. In the miocene and eocene strata some fossils occur which 

 compel us to go to America for the nearest representatives. To match the mam- 

 malian remains from the English oolitic formations, we must bring species from 

 the Antipodes. These are truly most suggestive facts. If the present laws of 

 geographical distribution depend, in an important degree, upon the present con- 

 figuration and position of continents and islands, what a total change in the geo- 

 graphical character of the earth's surface must have taken place since the " Stones- 

 field slate" was deposited in what now forms the County of Oxfordshire 1 These 

 and the like considerations from the modifications of geographical distribution of 

 particular forms or groups of animals, warn us how inadequate must be the phe- 

 nomena connected with the present distribution of land and sea to guide to the 

 determination of the primary ontological divisions of the earth's surlace. Some 

 of the latest contributions to this most interesting branch of natural history have 

 been the result of endeavours to determine whether, and how many, distinct cre- 

 ations of plants and animals have taken place. But i would submit that the dis- 

 covery of two portions of the globe, of which the respective Faunse and Florae 

 are different, by no means aifords the requisite basis for concluding as to distinct 

 acts of creation. Such conclusion is associated, perhaps unconsciously, with the 

 idea of the historical date of creative acts : it presupposes that the portion of the 

 globe so investigated by the botanist and zoologist has been a separate and prima- 

 tive creation, — that its geographical limits and features are still in the main what 

 they were when the creative fiat -w^eat forth. But geology has demonstrated that 



