"6 THE ORIGIN OF SPECIES 4 
operation which. can be effected by Nature, for mar 
interferes intelligently. Reduced to its elements 
this argument implies that an effect produced witl 
trouble by an intelligent agent must, @ fortiori, be 
more troublesome, if not impossible, to an uni 
telligent agent. Even putting aside the questio: 
whether Nature, acting as she does according t 
definite and invariable laws, can be rightly callec 
an unintelligent agent, such a position as this i 
wholly untenable. Mix salt and sand, and it shal 
puzzle the wisest of men, with his mere natura 
pliances, to “separate all the grains of sand_fron: 
nile the grains of salt ; but a shower of rain wil 
effect the same “Obiect in ten minutes. And sc 
while man may find it tax all his intelligence t 
separate any variety which arises, and to bree: 
selectively from it, the destructive agencies ince 
santly at work in Nature, if they find one variet 
to be more soluble in circumstances than the othe. 
will inevitably, in the long run, eliminate it. 
A frequent anda just objection to the Lamarckia. 
hypothesis of the transmutation of species is base” 
upon the absence of transitional forms betwee: 
many species, But against the Darwinian hype. 
thesis this argument has no force. Indeed, one « 
the most valuable and suggestive parts of M 
Darwin’s work is that in which he proves, the 
the frequent absence of transitions is a necessar 
consequence of his doctrine, and that the stoc 
whence two or more species have sprung, need 1 
