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be found to be based on some foundation. Vox populi, vox Dei , is 
true in more sciences than politics. Passing this, however, I 
would next notice that the phenomena of hybridization do not 
stop with the lav/ allowing the hybrid to have fertile offspring 
from the parent stock; there is another law which prevents it 
having such offspring from other hybrids or other species, and 
this is quite in accordance with my view of the precautions adopted 
by nature for the preservation of species. In the first place, 
fertility , to preserve it from extinction by extirpation of indivi- 
duals ; in the second place, sterility , to preserve it from extinction 
by confusion of races. Such are my views of the purpose and work- 
ing of the compensating qualities implanted in species. And my 
first objection to the principles on which Mr Darwin’s theory rests 
is, that it is founded on exaggerated and undue estimate of the one — - 
the power of modification ; and if not a negation, at least an inade- 
quate concession of the other, viz. the principle of reversion to 
type. 
Seeing, then, that the power of modification or variation is the 
principle on which his whole superstructure rests, Mr Darwin wisely 
takes care to fortify it by adducing striking instances illustrative of 
the extent to which this may take place. As the power of modifi- 
cation is to be seen in its most developed form in domestic animals, 
it is from them chiefly — indeed, so far as support to his theory 
goes, I may say it is from them entirely — that his illustrations 
are drawn. Now, it is usually said that domestic animals are not 
fair examples from which to reason in inquiries into species and 
their origin ; and it is thought that the artificial circumstances 
under which they live alter their system so much as to render any 
argument drawn from them not worthy of reliance. I have no doubt 
that such artificial life and great change of habits has an impor- 
tant effect upon these animals, and more especially upon their re- 
productive system, different conditions of which (as Mr Darwin 
has well shown) have much effect in inducing subsequent variations 
in their descendants; but, as already said, I imagine a still more 
potent cause of the greater variability of domesticated animals to 
lie in their being deprived, through the agency of man, of the 
opportunity of allowing the revertive principle to come into opera- 
tion by intercrossing. But it is no part of my argument to dispute 
the power of variation within certain limits ; and as, for the above 
