ORDER II. 

 INSESSORES, VIGORS. 



THE Insessores, or Perching Birds, form the second and 

 pre-eminently typical order of the class, comprehending all 

 that vast assemblage of species distinguished by LINN^US 

 and others under the separate orders Pica and Passeres. 

 This division of the earlier systematists is entirely artificial, 

 being instituted without any due regard to the true affinities 

 of the species. As such, it has been rejected by CUVIER,* 

 who declares his inability to detect any character of distinc- 

 tion either internal or external, which can warrant so abso- 

 lute a separation ; and VIGORS, SWAINSON, and other eminent 

 ornithologists of the present day, have shown that an un- 

 broken chain and circular succession of affinities does exist 

 throughout the whole of these birds ; and that the subordi- 

 nate groups into which the order is divisible (complete as 

 each may appear within itself), are too intimately connected 

 with each other, to admit of a separation so absolute as that 

 adopted by LINN^US and his followers. In an order of such 

 extent, and which contains so great a variety of form, a con- 

 siderable difficulty has been experienced in selecting charac- 

 ters sufficiently comprehensive to define it. On this account, 

 some have merely assigned to it absence of certain qualities, 

 as contrasted with the other orders ; but Mr SWAINSON-}- has 

 pointed out three distinct characters, two of which he consi- 

 ders as universal, and the third as especially applicable to 



In the " Regne Animal," he observes in a note, " Malgre" tous mes 

 efforts, il m'a e'te' impossible de trouver, ni a 1'exterieur, ni a 1'interieur, 

 aucun caractere propre a separer des passereaux aux des genres compris 

 parmi les Piece de LINN.EUS, qui ne sont pas grimpeurs." 



t See Northern Zoology, vol. ii. p. 100, &c. 



