WORK IN PALAAONTOLOGY 153 
were of the same species; since the races or varieties 
of dogs have been influenced by the trammels of 
domestication, which these other animals never did 
and indeed never could experience.” * 
The extreme views of Cuvier as to the frequent 
renewal and extinction of life were afterward (in 1850) 
carried out to an exaggerated extent by D’Orbigny, 
who maintained that the life of the earth must have 
become extinct and again renewed twenty-seven 
times. Similar views were held by Agassiz, who, 
however, maintained the geological succession of ani- 
mals and the parallelism between their embryonic 
development and geological succession, the two foun- 
dation stones of the biogenetic law of Haeckel. But 
immediately after the publication of Cuvier’s Ossemens 
fossiles, as early as 1813, Von Schlotheim, the founder 
of vegetable paleontology, refused to admit that each 
set of beds was the result of such a thoroughgoing 
revolution.t 
At a later date Bronn “demonstrated that certain 
species indeed really passed from one formation to 
* Discours, etc. Sixth edition. 
+ Felix Bernard, Zhe Principles of Paleontology, Paris, 1895, trans- 
lated by C. E. Brooks, edited by J. M. Clark, from 14th Annual Re- 
port } New York State Geologist, 1895, pp. 127-217 (p. 16). Bernard 
gives no reference to the work in which Schlotheim expressed this 
opinion. E. v. Schlotheim’s first work, /Vora der Vorwelt, appeared 
in 1804, entitled Beschreibung merkwiirdiger Kratiterabdrticke und 
Pflanzenverstetnerungen. Lin Beytrag zur Flora der Vorvelt. 1 
Abtheil. Mit 14 Kpfrn. 4°. Gotha, 1804. A later work was 
Beytrége zur Naturgeschichte der Versteinerungen in geognostischer 
Hinsicht (Denkschri ft ad. k, Academie da. Wissenschaften su Mtinchen 
fiir den Jahren 1816 wzd 1817. 8 Taf. Miinchen, 1819). He was 
followed in Germany by Sternberg (Versuch einer geognostischbotan- 
tschen Darstellung der Flora der Vorvelt, 1-8. 1811. Leipzig, 
1820-38) ; andin France bys A ae Brongniart, 1801-1876 (Aistotre des 
Vegétaux " fossiles, 1828). These were the pioneers in paleeophytology. 
