Cretecesms of Theory of Natural Selection. 341 
I will now pass on to consider another miscon- 
ception of the Darwinian theory, which is very 
prevalent in the public mind. It is virtually asked, 
If some species are supposed to have been improved 
by natural selection, why have not all species been 
similarly improved? Why should not all inverte- 
understandings. One of the latter it is necessary to state, because it 
pervades the quotation which I am about to supply. He everywhere 
compares ‘‘natural selection” with “the struggle for existence,” uses 
them as convertible terms, and while absurdly stating that “ Darwin 
defines natural selection as the struggle for existence,” complains of 
“the liability of error, both on his own part and on the part of his 
readers,” which arises from his not having everywhere adheied to this 
definition! (p. 8). 
‘* Darwin has put forth two distinct and contradictory theories of the 
functions of ratural selection. According to the one theory natural 
selection is selective or preservative, and nothing more. According to 
the other theory natural selection creates the variations (!)... It cer- 
tainly seems absurd to speak of natural selection, or the struggle for 
existence, as selective or preservative, for the struggle for existence 
does not preserve at all, not even the fit .ariations, as both the fit 
and the unfit struggle for existence, the unfit naturally more than the 
fit, and the fit are preserved, not in consequence of the struggle, but in 
consequence of their fitness. Suppose two varieties of the same species 
are driven, by an increase of their numbers, to seek for subsistence in a 
colder region than they have been accustomed to, and that one of these 
varieties had a hardier constitution than the other; and let us suppose 
that the former withstood the severe climate better than the latter, and 
consequently survived, while the other perished. In this case the hardier 
survived, not because of the struggle, but because it had a constitution 
better adapted to the climate. I wish to ascertain if a certain metal in 
my possession is gold or some baser metal, and I apply the usual test ; 
but the mere fact of my testing this metal would not make it gold or any 
other kind of metal.” 
I have thought it worth while to quote this passage for the sake of 
showing the extraordinary confusion of mind which still prevails on the 
part of Darwin’s critics, even with reference to the very fundamental 
parts of his theory. For, as I have said, the writer of this passage shows 
himself a shrewd critic in some other parts of his essay, where he is not 
engaged especially on the theory of natural selection. 
