CHAP. V.] CLASSIFICATION. 93 
the most highly organised, but only one of the most specialised 
forms of birds, and because their affinities are not with the 
Passeres, but rather with the cormorants and some other of the 
aquatic groups. The Passeres therefore are placed first; and the 
series of families is begun by the thrushes, which are certainly 
the most typical and generally well-organised form of birds. 
Instead of the Scansores and Fissirostres of the older authors, the 
order Picarize, which includes them both, is adepted, but with 
some reluctance; as the former are, generally speaking, well marked 
and strongly contrasted groups, although certain families have 
been shown to be intermediate. In the Picariz are included the 
goat-suckers, swifts, and humming-birds, sometimes separated 
as a distinct order, Macrochires. The parrots and the pigeons 
form each a separate order. The old groups of Gralle and 
Anseres are preserved, as more convenient than breaking them 
up into widely separated parts; for though the latter plan may 
in some cases more strictly represent their affinities, its details 
are not yet established, nor is it much used by ornithologists. 
In accordance with these views the following is the series of 
orders and families of birds adopted in this work: 
Class—A VES. 
Orders. 
Bea scpres ae the great mass of the smaller birds—Crows, 
‘ iy Finches, Flycatchers, Creepers, Honeysuckers, &c., &c. 
ee Picarii ane Woodpeckers, Cuckoos, Toucans, Kingfishers, 
wifts, &c., &. 
3. Psittaci ..._- Parrots only. 
4. Columbe ... Pigeons and the Dodo. 
' 5. Galline ..._ Grouse, Pheasants, Curassows, Mound-builders, &c. 
6. Opisthocomi The Hoazin only. 
7. Accipitres ... Eagles, Owls, and Vultures. 
8. Grallee ... Herons, Plovers, Rails, &c. 
9. Anseres ... Gulls, Ducks, Divers, &e 
10. Struthiones.... Ostrich, Cassowary, Apteryx, &c. 
The Passeres consist of fifty families, which may be arranged 
and grouped in series as follows. It must however be remem- 
bered that the first family in each series is not always that 
which is most allied to the last family of the preceding series. 
All extensive natural groups consist of divergent or branching 
alliances, which renders it impossible to arrange the whole in 
one continuous series. 
