448 THE ORIGIN OF SPECIES 



he does not show how selection acts under nature. He believes, 

 like Dean Herbert, that species, when nascent, were more plastic 

 than at present. He lays weight on what he calls the principle of 

 finality, "puissance mysterieuse, indeterminee ; fatalite pour les 

 uns; pour les autres volont6 providentielle, dont Taction inces- 

 sante sur les etres vivantes determine, a toutes les epoques de 

 I'existence du monde, la forme, le volume, et la duree de chacun 

 d'eux, en raison de sa destinee dans I'ordre de choses dont il fait 

 partie. C'est cette puissance qui harmonise chaque membre a 

 ['ensemble, en Fappropriant a la fonction qu'il doit remplir dans 

 i'organisme generale de la nature, fonction qui est pour lui sa 

 raison d'etre."* 



In 1853 a celebrated geologist, Count Keyserling ("Bulletin 

 de la Soc. Geolog.," 2d ser., tom. x. p. 357) suggested that as new 

 diseases, supposed to have been caused by some miasma, have 

 arisen and spread over the world, so at certain periods the germs 

 of existing species may have been chemically affected by circum- 

 ambient molecules of a particular nature, and thus have given 

 rise to new forms. 



In this same year, 1853, Dr. Schaaffhausen published an ex- 

 cellent pamphlet ("Verhand. des Naturhist. Vereins der Preuss. 

 Rheinlands," etc.), in which he maintains the development of 

 organic forms on the earth. He infers that many species have kept 

 true for long periods, whereas a few have become modified. The 

 distinction of species he explains by the destruction of interme- 

 diate graduated forms. "Thus living plants and animals are not 

 separated from the extinct by new creations, but are to be re- 

 garded as their descendants through continued reproduction." 



A well-known French botanist, M. Lecoq, writes in 1854 

 ("Etudes sur Geograph. Bot.," tom. i. p. 250): "On voit que nos 

 recherches sur la fixite ou la variation de I'espece, nous conduisent 

 directement aux idees emises par deux hommes justement cele- 

 bres, Geoffroy Saint-Hilaire et Goethe." Some other passages scat- 



* From references in Bronn's "Untersuchungen iiber die Entwickelungs- 

 Gesetze," it appears that the celebrated botanist and palaeontologist Unger 

 published, in 1852, his belief that species undergo development and modifi- 

 cation. Dalton, likewise, in Pander and Dalton's work on Fossil Sloths, ex- 

 pressed, in 1821, a similar belief. Similar views have, as is well known, been 

 maintained by Oken in his mystical "Natur-Philosophie." From other refer- 

 ences in Godron's work "Sur I'Espece," it seems that Bory St. Vincent, Bur- 

 dach, Poiret, and Fries have all admitted that new species are continually 

 being produced. I may add, that of the thirty-four authors named in this 

 Historical Sketch who believe in the modification of species, or at least dis- 

 believe in separate acts of creation, twenty-seven have written on special 

 branches of natural history or geology. 



