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us of the immense risk which would accompany the 
action of Natural Selection, if it were indeed a law of 
nature, while it is obvious that no such risk attends other 
possible modes of modification. Shall we, then, still 
say that the extinction is the work of Natural Selection? 
Shall we say that the extinct species has been “ eliminated 
by Natural Selection?” There is no doubt, in a certain 
sense, a selection ; “ one is taken and the other is left.” 
But surely this is not Natural Selection in the proper and 
definite and technical meaning of the term which implies 
not the survival of one species at the expense of another ; 
but the modification of a given species by the selection of 
variations which are useful to the species in the struggle 
for existence. If a cattle breeder were to kill off all of 
a particular breed for which there was no longer any 
demand, you would hardly call that artificial selection. 
From what has been said in the two previous chapters, 
it is certain that the transmutation of species, by whatever 
means it be brought about, has to compete with the two 
very different tendencies—the fixity of species and the 
extinction of spocies. The stability of species shows us 
how difficult it is in some cases to bring about any trans 
mutation of species ; the extinction of species warns 
us of the danger which may accompany this attempt. 
For the reasons which have already been assigned, the 
competition must be exceptionally bitter in those cases in 
which the reputed law of Natural Selection is brought into 
action. Hence it is probable that at the threshold of our 
enquiry Natural Selection may be excluded where other 
methods of transmutation are possible.