INDEFINITELY FROM THE ORIGINAL TYPE. 41 



existence, that what applies to the one is almost sure 

 not to apply to the other. Domestic animals are ab- 

 normal, irregular, artificial ; they are subject to varia- 

 tions which never occur and never can occur in a state 

 of nature : their very existence depends altogether on 

 human care ; so far are many of them removed from 

 that just proportion of faculties, that true balance of 

 organisation, by means of which alone an animal left 

 to its own resources can preserve its existence and 

 continue its race. 



Lamarck's Hypothesis very different from that now 

 advanced. 



The hypothesis of Lamarck that progressive changes 

 in species have been produced by the attempts of ani- 

 mals to increase the development of their own or- 

 gans, and thus modify their structure and habits has 

 been repeatedly and easily refuted by all writers on 

 the subject of varieties and species, and it seems to 

 have been considered that when this was done the 

 whole question has been finally settled ; but the view 

 here developed renders such hypothesis quite un- 

 necessary, by showing that similar results must be 

 produced by the action of principles constantly at 

 work in nature. The powerful retractile talons of 

 the falcon- and the cat-tribes have not been produced 

 or increased by the volition of those animals; but 

 among the different varieties which occurred in the 

 earlier and less highly organized forms of these 

 groups, those always survived longest which had the 



