520 



NATURE 



\Sept. 25, 1879 



thought it best to speak of the earlier periods more in detail, as 

 they are less generally known, and especially as they indicate 

 the growth of the science, and the obstacles it had to surmount. 

 With the present work in pateontology, moreover, you are all 

 more or less familiar, as the results are now part of the current 

 literature. To assign every important discovery to its author 

 would have led me far beyond my present plan. I have only 

 endeavoured to indicate the growth of the science by citing the 

 more prominent works that mark its progress, or illustrate the 

 prevailing opinions and state of knowledge at the time they were 

 written. 



In considering what has been accomplished, directly or 

 indirectly, it is well to bear in mind that without palaeontology 

 there would have been no science of geology. The latter 

 : cience originated from the study of fossils, and not the reverse, 

 as generally supposed. Palaeontology, therefore, is not a mere 

 branch of geology, but the foundation on which that science 

 mainly rests. This fact is a sufficient excuse, if one were wanting, 

 for noting the early opinions in regard to the changes of the 

 earth's surface, as these changes were first studied to explain 

 the position of fossils. The investigation of the latter first led 

 to theories of the earth's formation, and thus to geology. When 

 speculation replaced observation, fossils were discarded, and 

 for a time the mineral characters of strata were thought to 

 be the key to their position and age. For some time after this, 

 geologists, as we have seen, apologised for using fossils to 

 determine formations, but for the last half century their value 

 for this purpose has been fully recognised. 



The services which paleontology has rendered to botany 

 and zoology are less easy to estimate, but are very extensive. 

 The classification of these sciences has been rendered much 

 more complete by the intercalation of many intermediate forms. 

 The probable origin of various living species has been indicated 

 by the genealogies suggested by extinct types ; while our 

 knowledge of the geographical distribution of animals and 

 plants at the present day has been greatly improved by the facts 

 brought out in regard to the former distribution of life on the 

 globe. 



Among the vast number of new species which have been 

 added are the representatives of a number of new orders entirely 

 unknown among living forms. The distribution of these extinct 

 orders, among the different classes, is interesting, as they are 

 mainly confined to the higher groups. Among the fossil plants, 

 no new orders have yet been found. There are none known 

 among the protozoa or the moUusca. The radiates have been 

 enriched by the extinct orders of Blastoidea, Cystidea, and 

 Edrioasterida ; and the crustaceans by the Eurypterida and 

 Trilobita. Among the vertebrates no extinct order of fossil 

 fishes has yet been found ; but the amphibians have been 

 enlarged by the important order labyrinthodonta. The greatest 

 additions have been among the Reptiles, where the majority of 

 lire orders are extinct. Here we have at the present date the 

 Ichthyosauria, Sauranodontia, Plesiosauria, and Mosasauria 

 among the marine forms ; the Pterosauria, including the 

 I'teranodontia, containing the flying forms ; and the Dinosauria, 

 including the Sauropoda — the giants among reptiles ; likewise 

 the Dicynodontia and probably the Theriodontia, among the 

 terrestrial forms. Although but few fossil birds have been 

 found below the tertiary, we have already among the mesozoic 

 forms three new orders : the Saurura?, represented by Atchcc- 

 opteryx ; the OdontotormCE, with Ichthyornis as the type ; and 

 the Odontolcce, based upon Ilespa-ornis ; all of these orders 

 Ijeing included in the sub-class Odontornilhes, or toothed birds. 

 Among Mammals, the new groups regarded as orders are the 

 Toxodontia, and the Dinocerata, among the Ungulates ; and the 

 Tillodontia, including strange eocene mammals whose exact 

 affinities are yet to be determined. 



Among the important results in vertebrate palaeontology are 

 the genealogies, made out with considerable probability, for 

 various existing animals. Many of the larger mammals have 

 been traced back through allied forms in a closely-connected 

 series to early tertiary times. In several cases the series are so 

 complete that there can be little doubt that the line of descent 

 has been established. The evolution of the horse, for example, 

 is to-day demonstrated by the specimens now known. The 

 demonstration in one case stands for all. The evidence in favour 

 of the genealogy of the horse now rests on the same foundation 

 as the proof that any fossil bone once formed part of the skeleton 

 of a living animal. A special creation of a single bone is as 



probable as the special creation of a single species. The method 

 of the palaeontologist in the investigation of the one is the 

 method for the other. The only choice lies between natural 

 derivation and supernatural creation. 



For such reasons it is now regarded among the active workers 

 in science as a waste of time to discuss the truth of evolution. 

 The battle on this point has been fought and won. 



The geographical distribution of animals and plants, as well 

 as their migrations, have received much new light from paleon- 

 tology. The fossils found in some natural divisions of the earth 

 are related so closely to the forms now living there that a genetic 

 connection between them can hardly be doubted. The extinct 

 marsupials of Australia and the edentates of South America, are 

 well-known examples. The pliocene hippopotami of Asia and 

 the South of Europe point directly to migratioiLS from Africa. 

 Other similar examples are numerous. The fossil plants of the 

 Arctic region prove the existence of a climate there far milder 

 than at present, and recent researches at least render more 

 probable the suggestion, made long ago by BufTon, in his 

 " Epochs of Nature," that life began in the Polar regions, 

 and by successive migrations from them the continents were 

 peopled. 



The great services which comparative anatomy rendered to 

 paleontology at the hands of Cuvier, Agassiz, Owen, and 

 others, have been amply repaid. The solution of some of the 

 most difficult problems in anatomy has received scarcely less aid 

 from the extinct forms discovered than from embryology, and 

 the two lines of research supplement each other. Our present 

 knowledge of the vertebrate skull, ;the limb-arches, and the 

 limbs, has been much enlarged by researches in paleontology. 

 On the other hand, the recent labours of Gegenbaur, Hnx !ey, 

 Parker, Balfour, and Thacher, will make clear many obscme 

 points in ancient life. 



One of the important results of recent paleontological research 

 is the law of brain-growth, found to exist among extinct 

 mammals, and to some extent in other vertebrates. According 

 to this law, as I have briefly stated it elsewhere, "all tertiary 

 mammals had small brains. There was, also, a gradual increase 

 in the size of the brain during this period. This increase was 

 confined mainly to the cerebral hemispheres, or higher portions 

 of the brain. In some groups the convolutions of the brain have 

 gradually become more complicated. In some the cerebellum 

 and the olfactory lobes have even diminished in size." More 

 recent researches render it probable that the same general lav/ of 

 brain-growth holds good for birds and reptUes from the 

 mesozoic to the present time. The cretaceous birds, that bave 

 been investigated with reference to this point, had brains only 

 about one-third as large in proportion as those nearest allial 

 among living species. The dinosaurs from our Western Jurassic 

 follow the same law, and had brain cavities vastly smaller than 

 any existing reptiles. Many other facts point in the same direc- 

 tion, and indicate that the general law will hold good for all 

 extinct vertebrates. 



Paleontology has rendered great service to the more recent 

 science of archeology. At the beginning of the present period a 

 re-examination of the evidence in regard to the antiquity of the 

 human race was going on, and important results were soon 

 attained. Evidence in favour of the presence of man on the 

 earth at a period far earlier than the accepted chronology of six 

 thousand years would imply, had been gradually accumulating, 

 but had been rejected from time to time by the highest authori- 

 ties. In 1823 Cuvier, Brongniart, and Buckland, and later, 

 Lyell, refused to admit that human relic, and the bones of 

 extinct animals found with them, were of the same geological 

 age, although experienced geologists, such as Boue and others, 

 had been convinced by collecting them. Christol, Series, and 

 Tournal, in France, and Schmerling in Belgium, had found 

 human remains in caves, associated closely with those of various 

 extinct mammals, and other similar facts were on record. 



Boucher de Perthes, in 184:, began to collect stone imple- 

 ments in the gravels of the valley of the Somme, and in 1847 

 published the first volume of his "Antiquites celtiques." In 

 this work he described the specimens he had found and asserted 

 their great antiquity. The facts as presented, however, were 

 not generally accepted. Twelve years later Falconer, Evans, 

 and Prestwich examined the same localities with care, became 

 convinced, and the results were published in 1859 and i860. 



