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 nevér 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 theit 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 
