Criticisms of Theory of Natural Selection. 375 
lieve it to have been the chief factor or principal cause, 
all the three objections in question necessarily vanish. 
For in this case, even if it be satisfactorily proved that 
the theory of natural selection is unable to explain the 
three classes of facts above mentioned, the theory is 
not thereby affected: facts of each and all of these 
classes may be consistently left by the theory to be 
explained by causes other than natural selection— 
whether these be so far capable or incapable of 
hypothetical formulation, Thus it is evident that 
whether the three’ objections above named are to 
be regarded as logically insurmountable by the 
theory, or, as Jogi on- -6xistent in respect to it, 
depends simply: er in which the theory 
itself is stated. * bs “9 
In the next volunie a great deal more will have to 
be Salgggpon these matters—especially with regard to 
the cafes other than natural selection which in my 
opinion are capable of explaining these so-called 
“difficulties.” In the present connexion, however, 
all I have attempted to show is, that, whatever may 
be thought touching the supplementary theories 
whereby I shall endeavour to explain the facts of 
inutility, cross-sterility, and non-occurrence of free: 
intercrossing, no one of these facts is entitled to rank 
as an objection against the theory of natural selection, 
unless we understand this theory to claim an ex- 
clusive prerogative in the field of organic evolution. 
This, as we have previously seen, is what Mr. Wallace 
does claim for it; whilé on the other hand, Mr. 
Darwin expressly—and even vehemently— repudiates 
the claim: from which it follows that all the three 
main objections against the theory of natural selection 
