and Classification of Birds. 267 



inferior larynx, which enables the voice to be modulated. In 

 the structure of the sternum, that important bone upon which 

 a bird may be said to be especially organized, and the varia- 

 tions of which afford indications of really natural groups, 

 more prominently, perhaps, than any other portion of the en- 

 tire structure, considered separately, — in the configuration of 

 the sternal apparatus there exists the most surprising uni- 

 formity throughout the most dissimilar genera modified up- 

 on this rudimental type ; while, as compared with the bony 

 framework of any other bird whatever, the skeletons of this 

 excessively numerous group, present as insulated a form as 

 do those of the parrots. The same may be asserted of the 

 alimentary organs, and of other essential details of the anato- 

 my : while, to descend to habit, we find that the process of 

 interweaving a nest is all but confined to the members of this 

 division : one or two species of parrot, the Trocliilidm, and 

 the singular genus Coitus, being the only exceptions that I 

 know of:* all other nest-builders merely heaping together 

 materials, which, in some instances, as in the swifts, and cer- 

 tain hummingbirds, are agglutinated by a viscid mucus, se- 

 creted by the large salivary glands of the bird. By far the 

 great majority of this division lay bluish or speckled eggs, of 

 what may be designated the ordinary form, smaller at one 

 end ; and the young have a few scattered plumules of down 

 when first excluded. The feet have constantly three toes 

 placed forwards, and one behind ; and are, in some rare in- 

 stances, syndactyle, (as in the allied genera Eurylaimus, Ca- 

 lyptomenes, Rupicola, and Pipra), but ordinarily present what 

 may be denominated the ccenodactylef structure, having the 

 third and fourth, or the outer and middle toes, basally con- 

 nected, and the second or inner one free to the articulation; 

 which form of foot, it may be added, even abnormally, is of 

 rare occurrence in other Insessores, and perfectly developed, 

 as in a thrush or raven, in no other. 



It is needless to observe that the establishment of the im- 

 portant order Cantrices overturns the whole fabric of the 

 quinary distribution of Insessores. I challenge the advocates 

 of the theory of universal gradation to bring forward a single 

 instance, wherein this comprehensive group merges into any 

 other. 



For convenience only, I have commenced by indicating 

 this distinct division; for I am by no means disposed to place 



* The extremely loose and ill-built nests, to judge from description, of the 

 nidificatory Cuculidce, I suspect to be constructed without interweaving. 

 t Koivo$ , ordinary, most prevalent : and AaHTi>Xo$. 



