HISTORICAL SKETCH 447 



far as the mere enunciation of the principle of natural selection 

 is concerned, it is quite immaterial whether or not Professor Owen 

 preceded me, for both of us, as shown in this historical sketch, 

 were long ago preceded by Dr. Wells and Mr. Matthews. 



M. Isidore Geoff roy Saint-Hilaire, in his lectures delivered in 



1850 (of which a resume appeared in the ''Revue et Mag. de 

 Zoolog.," Jan., 1851), briefly gives his reason for believing that 

 specific characters "sont fixes, pour chaque espece, tant qu'elle 

 se perpetue au milieu des memes circonstances: ils se modifient, 

 si les circonstances ambiantes viennent a changer." "En resum6, 

 Vohservation des animaux sauvages demontre deja la variabilite 

 limitce des especes. Les experiences sur les animaux sauvages 

 devenus domestiques, et sur les animaux domestiques redevenus 

 sauvages, la demontrent plus clairement encore. Ces memes ex- 

 periences prouvent, de plus, que les differences produites peuvent 

 etre de valeur gen^rique*' In his "Hist. Nat. Generale" (torn. ii. 

 p. 430, 1859) he amplifies analogous conclusions. 



From a circular lately issued it appears that Dr. Freke, in 



1851 ("Dublin Medical Press," p. 322), propounded the doctrine 

 that all organic beings have descended from one primordial form. 

 His grounds of belief and treatment of the subject are wholly 

 different from mine; but as Dr. Freke has now (1861) published 

 his Essay on the "Origin of Species by means of Organic Affinity," 

 the difficult attempt to give any idea of his views would be super- 

 fluous on my part. 



Mr. Herbert Spencer, in an essay (originally published in the 

 "Leader," March, 1852, and republished in his "Essays," in 

 1858), has contrasted the theories of the Creation and the Devel- 

 opment of organic beings with remarkable skill and force. He 

 argues from the analogy of domestic productions, from the changes 

 which the embryos of many species undergo, from the difficulty 

 of distinguishing species and varieties, and from the principle of 

 general graduation, that species have been modified; and he 

 attributes the modification to the change of circumstances. The 

 author (1855) has also treated Psychology on the principle of 

 the necessary acquirement of each mental power and capacity by 

 gradation. 



In 1852 M. Naudin, a distinguished botanist, expressly stated, 

 in an admirable paper on the Origin of Species ("Revue Horti- 

 cole," p. 102; since partly republished in the "Nouvelles Archives 

 du Museum," tom. i. p. 171), his belief that species are formed 

 in an analogous manner as varieties are under cultivation; and 

 the latter process he attributes to man's power of selection. But 



