24 Mr. Swainson on the Typical Perfection 



who lays claim to the title of naturalist, practical or scientific, 

 in these days, can deny the difference between analogy and 

 affinity ; still less would he be bold enough to argue, that the 

 whole of creation is not a book of emblems, in the construction 

 of which there must be a plan, a harmony, and a design, per- 

 fect and consistent in all its parts. If, then, analogies exist, as 

 distinct from affinities, they must be universal. They may, 

 indeed, be so clear and immediate, as to strike every one with 

 a conviction of their truth : or they may be so disguised or 

 remote, as to lead shallow reasoners to pronounce them fan- 

 ciful; more particularly as of late much reason has been given, 

 by the speculations of certain continental writers, for such 

 imputations. That, however, which is fanciful, can never be 

 twisted into regularity ; for the moment a theory is found to 

 explain facts which have never been explained by any other, 

 it ceases to be fanciful. 



Having stated thus much, I shall proceed at once to com- 

 pare the Shovellers, the pre-eminent type of the genus, and of 

 the whole family of Anatidse, with the Conirostres, that being 

 the typical division of the order Insessores, or perching birds. 

 Both agree in being the types of their respective circles, and in 

 their wide, if not universal, geographic distribution. For 

 what particular office the singular lobed membrane of Malaco- 

 rhynchus is intended, must remain at present unexplained ; 

 but every principle of just reasoning authorises us to con- 

 clude, from analogy, that it is intimately connected either 

 with the nature of the food or the manner of capturing it, 

 peculiar to these birds ; it is remarkable also, that this mem- 

 brane is situated precisely at that part of the bill which in 

 dentirostral birds is occupied by the tooth ; both, in fact, are 

 appendages ; and the triangular membrane of these ducks is 

 shaped much in the same way as the tooth of the Shrike. The 

 colour of a species now before me strengthens this analogy, 

 since it is banded all over with those black stripes which so 

 particularly distinguish the American Thamnophilince, or bush- 

 shrikes. We may then fairly liken the sub-genus Malacorhyn- 

 chus to the Dentirostres. 



In the Gad walls we have a very peculiar plumage: it is 

 generally grey, and always dull. The British species is dis- 



