324 NATURAL SCIENCE [November 



Secondly. In the last sentence I commenced with a very large 

 " If " because I am afraid my heretical perversity carries me a good 

 deal further than I have yet dared to admit. 



Before Herbert Spencer held up his great lamp and bade us see 

 in animal and vegetable life not a discrete collection of disintegrated 

 units but a continuous unbroken chain, it was prudent and wise 

 perhaps to be content with an arrangement of the stratified beds 

 marked by no other law or rule than their mere order of super- 

 position in any particular place. This will no longer content us. 

 We want to know a great deal more than this. We want to know 

 what was the route and road by which a particular fauna and flora 

 came to occupy a particular zoological or botanical province, 

 and what were the stages of its growth and development. For 

 this supreme purpose we must go further afield than merely 

 examine the column of strata existing in any particular place. A 

 very cursory examination at once shows us that in every such 

 column marine beds are intercalated with sub-aerial beds, and no 

 ingenuity can possibly derive the fauna of the land from that of 

 the sea and vice versd by successive jumps and starts. They have 

 absolutely nothing to do with each other, and if our purpose is not 

 merely to calendar the revolutions of land and sea which have 

 occurred in a particular place, but to trace out the history of the 

 particular fauna occupying a particular province, either of the land 

 or of the sea, and thus to track the continuous history of each of 

 these divergent portions of the earth's surface along lines of con- 

 tinuity and growth, we must absolutely discard our present method 

 of geological arrangement and nomenclature for a very different one. 

 In the first place (and the change is so obvious that it has always 

 seemed to me a paradox that it was not made long ago) we must 

 absolutely separate the marine beds from the sub-aerial ones, put 

 them into two entirely different columns and perhaps give them 

 entirely different names. To apply the term Pliocene to the marine 

 beds marked by the Norwich or the Weybourn Crag and to apply it 

 also to the sub-aerial beds known as the Forest bed, is not an illumin- 

 ating but a darkening process. These two sets of beds may have 

 been contemporary but they have no other element in common, and 

 it is utterly misleading to give them a common name because the 

 marine and land debris are sometimes mixed as in the Norwich 

 Crag just as Ammonites and Mammoths both may be mixed with 

 striated boulders in the soft beds on the coast of Holderness. If we 

 are to retain our present geological nomenclature for the pan-arctic 

 region we must qualify each name by a distinctive epithet showing 

 whether the bed we mean is in the marine or the sub-aerial series. 



Again, we continually read in geological books of unconform- 

 ability, an excellent term expressing a very patent fact when we 



