CLASS II. AVES: OEDER 2. PASSEKES. 
79 
ORDER 2. PASSERES. 
The term Passeres is derived from the Latin Passer, a Sparrow ; its signification here is not 
' very obvious, but it may be taken as meaning a group of birds that perch like the sparrow ; in 
other words, the Passeres are Perching- Birds, and this order is the same as the Insessores — a teriii 
derived from the Latin insessus, and meaning j^f^rckinr/ — of many authors. It inchides not only a 
great number of genera and species, but a great diversity of kinds, some very unlike others. They 
appi-oach closely to the scansorial or climbing birds, which, in fact, might perhaps with propriety 
be united with them to form a single order, as the principal distinction consists in the structure 
of the feet, which in the Passeres possess four toes — three directed forward and one backward. 
This distinction is, however, more apparent than real, as several of the passerine birds have the 
power of turning one of the toes backward at pleasure ; and the cuckoos can turn one of their 
hind toes forward. The tarsi and toes are always scutellate, and the hinder portion and sides of 
the former are usually covered with a single horny plate, which is also sometimes the case with 
the anterior surface of this part of the leg. The legs and feet aie generally slight, and the claws, 
although curved, never constitute povs^crful hooked talons, as in the predaceous birds. 
The power of flight is possessed in great perfection by most of these birds; the wings are large 
and powerful, and the crest of the sternum very well developed. The primary quill feathers of 
the wing are generally ten in number; but the first of these is frequently wanting, or very small 
The tail is usually composed of twelve quill feathers. The bill is very variable in form, some- 
: times elongated and slender, sometimes stout and conical, or depressed and opening with a very 
wide gape. The upper mandible is frequently more or less toothed near the tip. From these 
peculiarities in the form of the bill the primary classification of these bivds most generally in use 
I is derived, each form being characteristic of a group or sub-order. Thus the birds in which the 
I bill is more or less depressed, with a very wide gape, are called Fissirostres, and feed upon insects, 
' wbich they capture on the wing. Those which have the bill elongated and awl-shaped are called 
I Tenuirostres, and feed upon soft larvae and the juices of flowers ; and those with a somewhat con- 
\ ical bill, but toothed, and usually more or less hooked at the tip, are called Dentirostres, and feed 
I principally upon insects and fruits. Those with a stout conical bill, in which the upper mandible 
I is not distinctly toothed, are called Conirostres ; in these the bill is usually employed in crushing 
t the hard seeds which constitute their food. The oesophagus of these birds is usually dilated into 
a sort of crop ; the stomach forms a powerful muscular gizzard, and the intestine is furnished 
with two coeca, generally very small. Many of them have also a complicated muscular apparatus 
at the lower larynx, which enables them to produce charmingly modulated notes. 
