402 HISTORY OF ZOOLOGY. 



an account of the great works of natural history 

 to which this accumulation of materials gave rise ; 

 such as the magnificent work of Bloch on Fishes, 

 which appeared in 1782 1785 : nor need I at- 

 tempt, by his assistance, to characterize or place in 

 their due position the several systems of classifica- 

 tion proposed about this time. But in the course 

 of these various essays, the distinction of the arti- 

 ficial and natural methods of classification came 

 more clearly into view than before ; and this is a 

 point so important to the philosophy of the subject, 

 that we must devote a few words to it. 



Separation of the Artificial and Natural Methods 

 in Ichthyology. It has already been said that all 

 so-called artificial methods of classification must 

 be natural, at least as to the narrowest members of 

 the system : thus the artificial Linnsean method is 

 natural as to species, and even as to genera. And 

 on the other hand, all proposed natural methods, 

 so long as they remain unmodified, are artificial 

 as to their characteristic marks. Thus a Natural 

 Method is an attempt to provide positive and dis- 

 tinct characters for the wider as well as for the 

 narrower natural groups. These considerations 

 are applicable to zoology as well as to botany. But 

 the question, how we know natural groups before 

 we find marks for them, was, in botany, as we 

 have seen, susceptible only of vague and obscure 

 answers: the mind forms them, it was said, by 

 taking the aggregate of all the characters; or by 



