292 FIRST PRINCIPLES OF NATURAL CLASSIFICATION. 



system of nature. Having already gone into all neces- 

 sary proofs and details respecting the family to which 

 it belongSj in another work *, we shall at present merely 

 recapitulate the resvdts thereby obtained. The Syl- 

 viadce, or warblers, are a circular group, holding the rank 

 of a family in the tribe of Dentirostres, or tooth-billed 

 birds. This family is again divided into sub-families 

 corresponding to, and representing, the primary types of 

 nature. Now, one of those types is the Rasorial, 

 which is the same as the Scansorial among the Perchers, 

 and in it we consequently find all those warblers which, 

 like the titmice, climb among trees more than any 

 other warblers, and thus aptly represent the Scansorial 

 parrots and woodpeckers. Still proceeding to analyse 

 the contents of every minor division, we have shown 

 that the PariancB, or titmice, form a circle of their own, 

 and are again divided into genera, the characters and 

 analogies of which have been thus stated + : — 



Sub-Family PARIANS. Titmice. 



Analogical Characters. Genera. Analogies. 



1. Typical group. , 1> , 



Bill short, strong, conic, entire. Parus. ComkO!>tres. Insessobes. 



2. Sub-typical group. 



Bill more lengthened and slen-f 

 der, slightly notched sotne- V Sylvicola. Dentirostres. Raptohes. 

 vihat remotely from, the tip. j 



3. Aberrant group. 



Feet more especially adapted lSet()phaga.~iTissinosTTiES Natatores. 

 either for perching, tvalking, ^Trichas. >Te.nuiro3tre3. Grallatores. 

 or climbing : bill various. J Accentor, j Scansores. Rasores. 



{SBS.") Thus it is shown that although the PariancB, 

 as a whole, represent the scansorial and rasorial division 

 of the warblers, stiU that this division contains within 

 itself representations of all the other types, and is there- 

 fore a perfect and circular group. If we spoke of the 

 titmice generally, we should consequently term them 

 the scansorial division or type of the warblers ; but, 

 if we wished to be more particular, and to name the 

 precise rank of the genus Parus, in its own circle, we 

 say that it is the typical genus. M. Cuvier has long 



* North. Zool. vol U. p. 203. + Id. ibid. 



