562 



SCIENCE. 



[N. S. Vol. XI. No. 276. 



cult one and is by no means complete. 

 The kind co-operation of the leading pale- 

 ontologists of Europe was enlisted and as 

 a result an approximate coi'relation sheet 

 was prepared. This was virtually a report 

 of progress in this investigation, main em- 

 phasis being laid upon geological succession. 

 In continuing the subject this year, main 

 emphasis will be laid upon faunal succession 

 or the distribution of the different orders 

 and families of mammals, concluding with 

 the latest views as to the succession of life 

 during the Pleistocene period in Europe. 



iYFi«<;y.;iFM Jp,™™ _■'■• 



Chaet I. — Preliminary Correlation Table of Euro- 

 pean and American Tertiary Horizons. On all the 

 levels above the Stampien the parallels are imper- 

 fectly established. 



The preliminary correlation sheet abbre- 

 viated in Chart I. sets forth the results of 

 the geological succession and correlation so 

 far as it has been carried at present and 

 illustrates the rapid progress of our knowl- 

 edge of our own horizons. It includes the 

 latest results of the American Museum ex- 

 plorations in the Miocene of Colorado and 

 Kansas, as roughly studied by Matthew, 

 but these correlations are not to be under- 



stood as final. Scott has already trans- 

 ferred our John Day of Oregon, from the 

 Miocene, where it was formerly placed, to 

 the Upper Oligocene. The lower part at 

 least of these beds belongs in the Oligocene 

 — while the .Upper John Day may prove 

 to correspond with the Lower Miocene of 

 Europe. Our Pliocene record as compared 

 with the magnificent Pliocene of Europe is 

 extremely meagre and our Miocene succes- 

 sion rich as it is, is not as fully understood 

 as the Miocene of France. We look for 

 more exact results from the American 

 Museum explorations which are now being 

 collated. It is only when we pass into the 

 great time period from the Oligocene down- 

 wards that the American record becomes a 

 superbly complete time standard for the 

 whole Northern Hemisphere or Holarctic 

 Region. 



TEETIAEY GEOGEAPHICAL DISTRIBUTION. 



The importance of geographical distri- 

 bution was first recognized by Humboldt, 

 and set forth by Darwin in the ' Origin of 

 Species,' in 1858. In the same year Sclater 

 divided the world into eastern and west- 

 ern divisions or Palaeogsea and Neogaea, 

 to embrace the Old and New Worlds re- 

 spectively, a division which has proved to 

 be totally illogical. This led Darwin's dis- 

 tinguished colleague, Alfred Wallace, to his 

 great work upon the ' Geographical Distri- 

 bution of Animals ' and the division of the 

 world into life regions ; in which Sclater's 

 scheme was adopted and developed.* In 

 1S6S, Huxley divided the world into a north- 

 ern division, Arctogsea, and a southern 

 division Notogsea to include the Northern 

 and Southern Hemispheres respectively ; 

 this division was a little nearer the truth 

 than Sclater's. Between 1868 and 1890, 



*The history of opinion upon this subject is fully 

 set forth by Lydekker's invaluable work the ' Geo- 

 graphical Distribution of Mammals,' published in 

 1896. 



