de Zoolog.,' Jan. 1851), briefly gives his reason for believing that specific characters "sont
fixés, fixés, 1872 | fixes, 1861 1866 1869 |
pour chaque espèce, tant qu'elle se perpétue au milieu des mêmes circonstances: ils se modifient, si les circonstances
ambiantes ambiantes 1861 1866 1872 | am- biantes 1869 |
viennent à
changer." "En résumé,
l
'
observation
des animaux sauvages démontre déjà la variabilité
limitée
des espèces.
changer." "En résumé,
l
'
observation
des animaux sauvages démontre déjà la variabilité
limitée
des espèces.
1872 |
changer." 1861 1866 1869 |
↑1 blocks not present in 1872; present in 1861 1866 1869 | "En résumé, l
'
observation des animaux sauvages démontre déjà la variabilité
limitée
des espèces.
|
Les
expériences
sur les animaux sauvages devenus domestiques, et sur les animaux domestiques redevenus sauvages, la démontrent plus clairement encore. Ces mêmes expériences prouvent, de plus, que les différences produites peuvent être de
valeur
générique
." In his 'Hist. Nat. Générale' (tom. iI. p. 430, 1859) he amplifies analogous conclusions.
générique
." In his 'Hist. Nat. Générale' (tom. iI. p. 430, 1859) he amplifies analogous conclusions.
1872 |
générique
."
1861 1869 |
générique."
1866 |
|
|
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 superfluous 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 Development 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 gradation, 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.e gradation.e 1872 | gradation. 1861 1866 1869 |
|
|
In 1852
...OMIT 1866 1869 1872 |
('Revue Horticole,' p. 102) 1861 |
M. Naudin, a distinguished botanist,
....... 1866 1869 1872 | has 1861 |
expressly
stated, stated, 1866 1869 1872 | stated 1861 |
in an admirable paper on the Origin of Species ('Revue Horticole,' p. 102; since partly republished in the 'Nouvelles Archives du Muséum,' tom. I. p. 171), his belief that species are formed in an in an admirable paper on the Origin of Species ('Revue Horticole,' p. 102; since partly republished in the 'Nouvelles Archives du Muséum,' tom. I. p. 171), his belief that species are formed in an 1866 1872 |
his belief that species are formed in an 1861 |
in an admirable paper on the Origin of Species ('Revue Horticole,' p. 102; since partly republished in the 'Nouvelles Archives du Muséum,' tom. i. p. 171), his belief that species are formed in an 1869 |
analogous manner as varieties are under cultivation; and the latter process he attributes to man's power of selection. But 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 mystérieuse, indéterminée; fatalité pour les uns; pour les autres, volonté providentielle, dont l'action incessante sur les êtres vivants détermine, à toutes les époques de l'existence du monde, la forme, le volume, et la durée de chacun d'eux, en raison
|