Osteological Characters in Ornithology. 37 



arrived at identical results from a cousideration of the general 

 external structure, habits, and affinities of the birds in question, 

 and with but little or no knowledge of their osteology. In my 

 paper on " A Natural Arrangement of Birds " in the ' Annals and 

 Magazine of Natural History^ for 1856 (vol. xviii. p. 214), I 

 separate from the Passeres every family which M. Blanchard has 

 separated, and of the rest I remark, " There remains an extensive 

 series of species which we believe constitutes one great group of 

 equal value with those we have already defined. This group may 

 be called the normal or typical Passeres, and consists of above 

 thirty -five families, containing between three and four thousand 

 species, or at least half of the known birds. These, we believe, are 

 too intimately connected with each other to allow of their being 

 separated into a few great divisions without violating many of 

 their natural relations. They have all normal or ^-toed feet, 

 which are never so short or weak as to be unadapted for pro- 

 gression. The bill is always moderate in size and form, and in 

 the few cases where it is peculiarly modified (as in some species 

 of Dendrocolaptidce) other species in the same family possess 

 the normal form. There is also a remarkable moderation in 

 size; for though the species are so numerous, there are none 

 either so large or so small as are to be found in the two 

 abnormal groups. There is also a much greater uniformity in 

 texture of plumage and in form, as well as in habits, which 

 binds the whole into one compact and natural group. It is also 

 a most important point to consider that there are no isolated 

 families — none but have numerous points of connexion and tran- 

 sition with others ; and to such an extent is this the case, that 

 there is scarcely an extensive family group about the limits of 

 which ornithologists can agree. The Thrushes, Warblers, Fly- 

 catchers, Chatterers, Tanagers, Finches, Shrikes, Bush- Shrikes, 

 and many others are in this condition, and ofi'er a striking con- 

 trast to the families of the Fissirostres and Scansores, about the 

 limits of every one of which there i& scarcely any doubt or diffi- 

 culty whatever. Here then we have three groups, one of which, 

 though very much more extensive than the others, offers less 

 variation in the form and size of the species and in the modifi- 

 cations of their principal organs. Correct principles of classifi- 



