PASSERINE. 
177 
THE SECOND ORDER OF BIRDS. 
THE PASSERINE. 
This is the most numerous order of the whole class. Its character seems, at first sight, 
purely negative, for it embraces all those Birds which are neither swimmers, waders, climbers, 
rapacious, nor gallinaceous. Nevertheless, by comparing them, a very great mutual resem- 
blance of structure becomes perceptible, and particularly such insensible gradations from one 
genus to another, that it is extremely difficult to establish the subdivisions. 
They have neither the violence of the Birds of Prey, nor the fixed regimen of the Poultry 
and Water-fowl ; insects, fruit, and grain, constitute their food, which consists more exclu- 
sively of grain as the beak is stouter and stronger, and of insects as it is more slender. Those 
in which it is strong even pursue other Birds. 
Their stomach is a muscular gizzard. They have, generally, two small coeca : and it is 
among them thstt we find the singing Birds, and the most complicated inferior larynx. 
The proportional length of their wings and the power of their flight are as various as their 
habits. 
The adult sternum has ordinarily but one emargination on each side of its posterior border. 
There are, however, two in the Rollers, Kingfishers, and Bee-eaters, [also in the Colies, 
Motmots, and Todies, which the author includes in this group,] and none whatever in the 
Swifts and Humming-birds. 
We institute our first partition according to the feet, and have then recourse to the beak. 
The first and most numerous division comprehends those genera in which the external toe 
is connected to the middle one as far as the first or second joint only. 
[This ordinal subdivision, properly restricted, is one of the most rigorously defined through- 
out nature, quite as much so as that of the Parrots. 
The entire skeleton, digestive and vocal organs, are peculiar ; and those genera included 
by the author which differ in one particular differ also in the rest, and accord in all their 
essential characters with another great group that follows. 
The lower larynx is always complicated, and operated upon by four distinct pairs of 
muscles ; besides which, the long sterno-tracheal pair — found in most other Birds — is gene- 
rally present, but reduced to extreme tenuity. This character excludes the Cuvieran genera 
Cypselus, Caprimulgus, Podargus, Colius, Coracias, Colaris, Upupa, Merops, Prionites, Alcedo, 
Ceyx, Todus, and Buceros, — ten of which have also no intestinal coeca, and the three others 
very large coeca, exactly resembling those of the Owls (fig. 79)* All the remaining genera, 
except the Humming-birds, w'hich also require to be excluded, have two minute coeca. 
With the sole exception again of the Humming-birds, which have the lower larynx diffe- 
rently complicated, all singing Birds belong to this great order : the conformation alluded to 
enables them to inflect and modulate the voice ; though there are many species, possessing 
the same structure, which nevertheless utter only monotonous cries, and others of which the 
notes are harsh and little varied ; even these, however, are very generally capable of being 
taught to speak, to whistle airs, and to imitate almost any sound ; and in such individuals as 
cannot be brought to do so, it by no means follows that there is any physical deficiency, as 
indicated by the diversity noticeable in this respect in individuals of the same species : there 
are indeed very few of them, if any, that do not sing, or utter some peculiar note or chatter 
analogous to song, during the season of courtship. 
The sternal apparatus, whether of a Swallow or Tree-creeper, a Promerops, Finch, Crow, 
Thrush, or Manakin, presents invariably the same peculiar characters, with scarcely any modi- 
fication. The long manubrial process in front between the coracoids, with slantingly truncate 
bifurcate tip ; the costal process, expanding anteriorly much beyond the articulations of the 
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