PROVINCES OF TERRESTRIAL LIFE. 461 



that we are able to attack the problem of identification and correla- 

 tion of strata by means of the life they contain. It must be the 

 palaeontologist's endeavour to know the history of life, genus by 

 genus, and fauna by fauna, accurately tracing distribution in time, 

 and distribution in space, as it varied with the succession of geolo- 

 gical ages. Hence, every fossil has a value as a member of a fauna, 

 infinitely more important than its value as a characteristic species 

 of a stratum ; and the aim of the geologist in collecting fossils from 

 strata is more a demonstration of the history and evolution of life, 

 than the division of geological time into successive epochs, which have 

 no meaning except as recording the physical history of life on the earth. 



The student finds life provinces superimposed upon each other in 

 the sequence of the strata, and soon discovers that these life provinces 

 varied in past time with geographical distribution in a way similar to 

 their variation on the earth's surface now ; and in proportion to the 

 fulness of knowledge of this succession and variation of life, so will 

 be our success in converting the vertical succession of life preserved 

 in the strata back into the horizontal distribution of geographical pro- 

 vinces in the seas which geological formations represent. We have 

 no hesitation in affirming that the task is now within the student's 

 grasp ; for life provinces were clearly defined in the earliest epochs of 

 geological history which have been discovered. 



Sclater's Natural History Provinces. To Dr. P. L. Sclater 

 belongs the honour of having been the first to map out the division 

 of land life into six great provinces. He recognised, as others have 

 done before and since, the predominant influence of climate in giving 

 a similar facies to life in the same latitude. Dr. Sclater's provinces 

 are named Palaearctic, Nearctic, Neotropical, Ethiopian, Oriental, and 

 Australian. These divisions do not coincide with the existing divi- 

 sions of land, for Mexico and the West Indies are grouped with South 

 America; the Ethiopian region only comprises Africa, south of the 

 equator ; while the Oriental region, in addition to the Malay Archi- 

 pelago, takes in Southern China, India, and the intervening countries ; 

 while the Australian region includes New Zealand, Polynesia, New 

 Guinea, and other islands northward. 1 



Arctic Region. It is convenient to recognise, as does Joel Asaph 

 Allen, 2 a small arctic realm which unites the Palaearctic and Nearctic 

 regions. This area is characterised by the polar bear, 3 polar hare, 

 musk ox, arctic fox, lemmings, narwhal, white whale, and walrus. It 

 shares with the colder temperate region many seals, the reindeer, 

 moose, and some fur-bearing carnivora and rodents. 



Palceardic Region. The Palaearctic region, or northern zone of 

 the Old World, includes Europe and Iceland, the Azores, Canaries, and 

 Cape Verd Islands, Africa north of the Sahara, Asia as far as Affghan- 



1 Wallace : " Geographical Distribution of Animals." 



2 Bull U. S. Geol. and Geog. Surv. Territ., vol. iv. p. 313. 



3 It maybe useful to examine these types whenever possible in the Natural 

 History Collections of the British Museum, or other museums ; and in Zoological 

 gardens. 



