182 
nately the former error was perpetuated by Schwann and persisted 
for some time thereafter. 
103. Scnouw, JoAcniImM FREpErtc. 
Naturschilderungen. Kiel, 1840. 
German translation from the original Danish. 
“ Material nature has undergone a development. We have 
sought to demonstrate that the plant world and also the animal 
world shows evidence of an historical development,” not having 
been created “at once,” but “by degrees.” 
104. Scniouw, JoacHimM FRrepERIC. 
The Earth, plants, and man. Tondon, 1852. 
English translation from the German (1823) by Arthur Hen- 
trey, of this important pre-Darwinian discussion of the origin of 
species. Not in Pritzel. 
105. Scnouw, Joacuim FREDERIC. 
The origin of the existing vegetable creation. English transla- 
tion by N. Wallich from the Danish. (‘Transactions of the 
Meeting of Scandinavian Naturalists at Copenhagen in 1847.” 
Appendix K, p. 119.) Hooker's Journal of Botany and Kew Gar- 
den Miscellany 2, No. 23: 321-326; No. 24: 373-377. 1850, 
and 3, No. 25: 11-14. 1851. 
The existence of the same species of plant in widely separated 
countries is not due to migration from a “centrum” or single 
point of origin, but to the fact that “the same species has orig- 
inally appeared in several, often far distant, places.” (“ Schouw’s 
hypothesis.” This was earlier taught by Gmelin (1747), but 
was elaborated by Schouw. 
“T look upon it as highly probable, if not absolutely demon- 
strated, that no species are any longer created.” 
106. SCHWANN, THEODOR. 
Mikroskopische Untersuchungen iiber die Cbereinstimmung in 
der Struktur und dem Wachsthuim der Thiere und Pflanzen. 1839, 
The basis of the modern cell-theory—the foundation on w 
both animal and vegetable biology have developed. 
— 
uch 
