Criticisms of Theory of Natural Selection. 345 
Opposite objection has sometimes been urged—viz. 
that we ought never to find inferior forms of or- 
ganization in company with superior, because in the 
struggle for existence the latter ought to have exter- 
minated the former. Or, to quote the most recent 
expression of this view, “in every locality there 
would only be one species, and that the most highly 
organized ; and thus a few superior races would par- 
tition the earth amongst them to the entire exclusion 
of the innumerable varicties. species, genera, and orders 
which now inhabit it)” Of course to this statement 
it would be sufficient to enquire, On what would these 
few supremely organized species subsist? Unless 
manna fell from heaven for their especial bencfit, it 
would appear that such forms could under no circum- 
stances be the most improved forms; in exterminating 
others on such a scale as this, they would themselves 
be quickly, and very literally, improved off the face 
of the earth. But even when the statement is not 
made in so extravagant a form as this, it must neces- 
sarily be futile as an objection unless it has first been 
shown that we know exactly all the conditions of the 
complex struggle for existence between the higher 
and lower forms in question. And this it is impos- 
sible that we ever can know. The mere fact that 
one form has been changed in virtue of this struggle 
must in many cases of itself determine a change in 
the conditions of the struggle. Again, the other 
and closely allied forms (and these furnish the best 
grounds for the objection) may also have under- 
gone defensive changes, although these may be 
less conspicuous to our observation, or perhaps less 
1 Syme, on the Modification of Organisms, p. 46. 
