38 A. BLYTT. [NO. 1. 



gues of land were formed across the ocean like the ancient sup- 

 posed bridge of land in the line of the Faroe Islands and Ice- 

 land, from Scotland to Greenland; the warm ocean currents 

 would be shut out from the -higher latitudes. The Northern seas 

 would then become seas of ice, and. when the snowfall was suf- 

 ficient, inland ice would be formed. In a Memoir: Naturliche 

 Warmwasserheizung als Princip der klimatischen Zustande der 

 geologischen Formationen (in Abh. Senckenb. Ges. Frankf. a. M. 

 Vol. XIII, 1884 p. 277 ff.) J. Probst has, like Sartorius von 

 Waltershausm (Untersuchungen fiber die Klimate der Gegen- 

 wart und Vergangenheit 1865), rightly pointed out the great 

 importance that warm ocean currents have, and have had, in 

 tempering the climate of the higher latitudes. 



It has been a general supposition among geologists that the 

 animal and vegetable life of the ancient formations was much more 

 uniform over the entire Globe than it is now. But that opinion must 

 now be somewhat altered, in accordance with modern investigations. 

 J. W. Judd, says for instance (Nature I March 1888, p. 424 ff.) 

 in respect of the oldest beds containing fossils (the Cambrian): 

 „Even at that early period there were life provinces with a 

 distribution of organisms in space quite analogous to that which 

 exists at the present day." Examples of geographical provinces 

 are cited by him from the Silurian Triassic, Jurassic and 

 Cretaceous periods; and he further states: „I believe that the 

 study of fossils from remote parts of the earth's surface has 

 abundantly substantiated Prof. Huxley's suggestion that geo- 

 graphical provinces and zones may have been as distinctly 

 marked in the Palaeozoic epoch as at present." Most of the 

 beds of ancient times date from periods in which the land lay 

 low in relation to the sea; and the difference between the 

 geographical provinces is far less in the great ocean depths 

 than near the coasts and on the interior land. 



It has hitherto been an accepted doctrine, too, that the climate 

 of ancient days was much milder and more uniform over the whole 

 Earth than it is now. The farther back we go, it has been said, the 

 warmer was it, and that phenomenon has been placed in connection 



