256 ANNUAL KEPOET SMITHSONIAN INSTITUTION, 1916. 



This concentration on the sea and its life went to astonishing 

 lengths in the more ancient parts of geological history. Like most 

 of our older geologists, my first nourishment in the science was drawn 

 from Dana's "Manual." Unfortunately that earliest of textbooks 

 has been lost, but curiosity led me to glance over his fourth edition 

 (1895) to see how the dry land fares in its pages. 



There is the usual fiery introduction to historical geology, dividing 

 Archean times alliteratively into Astral, Azoic, and Archeozoic eons, 

 with a lithic era beginning at 2,500° F. and an oceanic era commenc- 

 ing when the earth had cooled to 500°, followed by eras of the earliest 

 plants and the earliest animals as the boiling ocean cooled to en- 

 durable temperatures. When the streaming waters had permanently 

 condensed in the hollows of the original crust there was left a V- 

 shaped nucleus of dry land about which the continent of North 

 America was to be built up. After this encouraging start with a 

 quite respectable dry-land area as a foundation, historical geology 

 becomes submerged in seas, mostly shallow, until the end of the 

 Silurian. Out of 114 pages devoted to this part of the world's 

 history the total number of lines referring to the land and its inhabi- 

 tants amount to only one page, while the Devonian land plants and 

 animals are given only 4 pages out of 46. It is true that most of the 

 Carboniferous chapter is devoted to the rank growths of the coal 

 swamps, but these amphibious plants have little to do with actual 

 dry land. They never rise far above sea level and are frequently 

 lowered beneath it to get a fresh covering of mud or sand. The 

 araucarias of the hills inland are barely mentioned, and it is not till 

 one gets well on into the Mesozoiothat the dinosaurs compel the student 

 to depart a little from the seashore. Even then there is a suggestion 

 that at least some of the clumsy beasts preferred splashing along the 

 mud flats or paddling in the lagoons. There is no hint of lean creatures 

 hastening with long strides to the shrinking water holes of a semi- 

 arid region. 



Another stand-by of student daj^s, this time in Germany, was 

 Credner's " Geologic," which up to the end of the Devonian gives 2 

 pages out of 58 to the land and its dwellers. Only 32^ pages out 

 of 300, up to the beginning of the Quaternary, have to do with 

 terrestrial things, even the dinosaurs almost escaping notice. The 

 dry land was evidently of small importance. 



It is not uimatural that in the beginning geology should devote 

 itself mainly to things marine, for the favored haunts of men are 

 almost all founded on stratified rocks. Werner's idea of a Avorld 

 deposited layer by layer from a primeval sea seemed reasonable 

 when he lectured in Freiberg, though the Bergakademie stands on 

 eruptive gneiss; and when William Smith began stratigraphic ge- 

 ology, on an island where one can never get many miles from the 



