Chapter 316

I have at last found time to read [the] first chapter of your "Dolomit Riffe" (285/1. "Dolomitriffe Sudtirols und Venetiens." Wien, 1878.), and have been exceedingly interested by it. What a wonderful change in the future of geological chronology you indicate, by assuming the descent-theory to be established, and then taking the graduated changes of the same group of organisms as the true standard! I never hoped to live to see such a step even proposed by any one. (285/2. Published in "Life and Letters," III., pages 234, 235.)

Nevertheless, I saw dimly that each bed in a formation could contain only the organisms proper to a certain depth, and to other there existing conditions, and that all the intermediate forms between one marine species and another could rarely be preserved in the same place and bed. Oppel, Neumayr, and yourself will confer a lasting and admirable service on the noble science of Geology, if you can spread your views so as to be generally known and accepted.

With respect to the continental and oceanic periods common to the whole northern hemisphere, to which you refer, I have sometimes speculated that the present distribution of the land and sea over the world may have formerly been very different to what it now is; and that new genera and families may have been developed on the shores of isolated tracts in the south, and afterwards spread to the north.