12 Mr. Swainson on the Typical Perfection 



gicae ;' and when they perceived that the variation of animal 

 structure could only be explained upon the principles there 

 promulgated. But regardless of the warning which the 

 talented author of that work has so often given to his disciples, 

 that nothing is more easy than to form circles upon paper, 

 ' provided we do not consider it necessary to prove them,' the 

 fascination of his theory has been such, that some of his fol- 

 lowers forgetful of the discriminating caution of their master, 

 and overlooking those tests which he has himself applied to 

 the only genera he has perfectly analyzed have ventured to 

 pronounce certain groups to be natural and circular, which, 

 upon closer investigation, prove eminently artificial. Certain 

 forms are fixed upon as types of structure, before the prin- 

 ciples which regulate such types have been either explained 

 or discovered. An arbitrary standard of perfection is thus 

 planted, around which are assembled such other species as 

 more or less approximate to this fancied point of excellence ; 

 as this, however, is founded upon no one fixed principle of 

 natural arrangement, every systematist thinks his own type 

 better than that of his predecessor. 



It appears to me, therefore, essentially necessary to the 

 stability of any system of zoology professing to be natural, 

 that the doctrine of types should be more deeply investigated : 

 since, if such forms do actually exist in nature, we are justified 

 in believing they must be regulated by certain general laws, 

 which, when developed, will be conspicuous in all natural 

 groups of animals. At all events, no arrangement can be 

 demonstrative which is in any degree founded upon an assump- 

 tion, like that of types, as they at present stand. It cannot be 

 too often repeated, that all true knowledge of zoology rests 

 exclusively upon analysis upon a perfect acquaintance not 

 only with the organization of a species, but with its habits, 

 instincts, and natural history, properly so called : to fix, a 

 priori, upon the type of a genus, or upon the divisions of a 

 family, before the first has been demonstrated, or the latter 

 analyzed, is manifestly erroneous : it is clearly beginning at 

 the wrong end ; and we do no more than tread in the foot- 

 steps of our predecessors, who first established certain rules of 

 their own for making genera, and then referred every new 



