364 HISTORY OF GEOLOGY AND PALEONTOLOGY. 



geographical provinces, and many other fascinating subjects 

 for scientific thought and investigation. 



The stratigraphical aspect of palaeontology is, however, the 

 chief care of the geologist. He has to unearth the fossils, 

 note their environment, trace the particular fossiliferous bed 

 of deposit in its farther extension, and observe whether the 

 fossils are only of sporadic occurrence in that horizon of 

 rock, or are distributed throughout wide areas ; again, whether, 

 the fossils are less frequent at that horizon than at some others 

 horizon a little above or a little below in the rock-succession,; 

 or if the fossils are so very abundant at that horizon as toj 

 represent leading fossil types, characteristic of that geological' 

 horizon or zone of rock. 



Many writers on fossil organisms have treated them merely 1 

 as a means of identifying the age of the rocks, and have! 

 neglected the biological features. More general interest is com- 

 manded by descriptions of complete faunas and floras belonging 

 to a definite epoch in the geological history of the earth. 

 Although monographs of this character are, in the first; 

 instance, of stratigraphical value, the data which they bring i 

 forward are of use in determining the development of organic j 

 creation. 



The first attempt at a Chronological Succession of fossil I 

 organisms is to be found in H. G. Bronn's 1 Lethaa Geognostica 

 (1835-38). This work is a masterpiece of scholarship; it sum- 



1 Heinrich Georg Bronn, born on the 3rd March 1800, at Ziegelhausen, 

 near Heidelberg, the son of a forester, studied in Heidelberg, and became 

 a university tutor there in 1821 ; in 1828 Professor of Zoology and Tech- 

 nology. Between 1824 and 1827 he travelled in Upper Italy and Southern 

 France for the sake of palseontological and geological studies. From 

 1830-62 he was one of the co-editors of the Jahrbuch fur Mineralogie, 

 Geognosie, und Pa'atontologie. His chief works, the Lethcea Geognostica, 

 the Handbook of Natural History, the Investigation into the Developmental 

 Laws of Organised Nature, brought him the reputation of being the most 

 distinguished palaeontologist in Germany. His difficulty of hearing was 

 a decided drawback to his teaching powers. Wissmann, Lommel, G. 

 Schweinfurth, and Zittel are among his grateful scholars. Bronn died in 

 1862 in Heidelberg, from lung disease. The first volume of the Lethcpa 

 Geognostica appeared in 1835, and was so widely circulated that a second 

 edition of it was called for before the publication of the second volume 

 the latter was published in 1838. A third edition in three volumes, and 

 with 124 plates, was published between 1851 and 1856, with the co-opera- 

 tion of Ferdinand Roemer, who had undertaken the preparation of the 

 Palaeo-Lethsea or Carboniferous Period. A fourth edition was begun in 

 1876 by Roemer, and is at present being continued by Professor Freeh. 



