NOTICES OF BOOKS. 251 



agreeing upon it. There are, as it appears to us, two broad facts, 



and only two, to which all naturalists must turn who seek some 



foundation for an opinion as to the origin of species, and these lead 



to diametrically opposite conclusions. They are, on the one hand, 



that a great number of specific forms are hereditary in as far as our 



experience allows of our judging ; on the other, that a great number 



are extremely variable, and that races with characters as strongly 



marked as those of species are constantly being produced under our 

 eyes. 



M. de Candolle belongs to the school who attach most importance 

 to the first fact, and he has put every argument that can be brought 

 forward in support of the conclusion to which it leads in the dearest 

 manner. He has also attended to all the facts that militate against it, 

 and if we do not think he has given them due prominence, it is from 

 no want of candour on his part, but solely from our considering that 

 he is not aware of their extent. We believe that species are very much 

 more variable than he does, and that the number of proved and pro- 

 bable permanent races (now regarded by most naturalists as species) is 

 much more numerous also. We do not indeed consider that the ques- 

 tion of species being definite creations is hence disposed of; for if 

 true, it proves no more than that there are fewer species than some 



Naturalists suppose. 



Let us now treat this side of the question upon its own merits. Its 

 advocates start with the fact that species are variable, and they assert 

 that this statement requires no qualification, whereas that of their he- 

 reditary distinctness* demands the qualificatiou of "within our expe- 

 rience/' But it has been shown that existing causes, and the range of 



our experience," will not account for a single fact in the present dis- 

 tribution of species, nor for the geographical origin of any, nor for the 

 amount of variation it has undergone, nor will it indicate the time 

 when it first appeared, nor the form it lia J when created ; in many 

 cases it will not even help us to discriminate a species from a variety, 

 or a hybrid from a species, or a monster from a perfect plant. What, 

 then, the opponent of the theory of definite creations asks, is the value 

 of the range of ^'our experience" in so momentous a question as thi«.. 

 Time and°altered conditions have, he says, within our experience, pro- 

 duced races that liave not reverted to their typical form ; it is allowiul 

 by the advocates of special creations, that these have oi)rr.ted from 

 periods which antedate the range of our experience, m conlouuduig 



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