TRANSLATOR'S NOTE. 



THE text of the original has been somewhat curtailed in the 

 translation, both in order to meet the wish of the author, and 

 to secure uniformity with the other volumes of the Con- 

 temporary Science Series. I have omitted entirely a chapter 

 of seventy-seven pages on Topographical Geology, which was 

 more special in character than any of the other chapters. I 

 have also omitted the lists of books of reference, taking care 

 to embody in the text all the more important publications ; 

 and have condensed the subject-matter wherever it seemed 

 possible to do so without detracting from the scientific 

 value of the History. These changes have been made 

 with the author's approval. It only remains to add that, 

 as a former pupil of Geheimrath Professor von Zittel's, and 

 one who bears very grateful feelings towards him, it has 

 Jed me great pleasure to translate this work. 



MARIA M. OGILVIE-GORDON. 



ABERDEEN, October 1901. 



