Bey grate Se te aes eee 
70 OSCINES, SINGING BIRDS. 
wards or even sideways; its claw is as long as, or longer than, the claw of the 
middle toe. The feet are never zygodactyle, nor syndactyle, nor semipalmate, 
though the front toes are usually immovably joined to each other at base, for a 
part, or the whole, of the basal joints. Various as are the shapes of the wings, 
these members agree in having the great row of coverts not 
longer than half the secondaries; the primaries either nine 
or ten in number, and the secondaries more than six. The 
tail, extremely variable in shape, has twelve rectrices (with 
certain anomalous exceptions). The bill is too variable to 
furnish characters of groups higher than families; but it is 
always cérneous, either wholly or in part, is never largely 
membranous, as in many wading and swimming birds, nor 
A\ cered, as in birds of prey. No Passeres are known to have 
Fic. 12. Passerine foot. more than one common carotid artery ; and they all have the 
sternum cast in one particular mould, with slight minor modifications of shape. 
They are the typical Insessores, as such representing the highest grade of develop- 
ment, and the most complex organization, of the class. Their high physical 
irritability is codrdinate with the rapidity of their respiration and circulation; they 
consume the most oxygen, and live the fastest, of all birds. They habitually reside 
above the earth, in the air that surrounds it, among the plants that with them adorn 
it ; not on the ground, nor on “‘ the waters under the earth.” 
Passeres, corresponding to the Insessores proper of most ornithologists, and 
comprising the great majority of birds, are divisible into two groups, commonly 
called suborders, mainly according to the structure of the lower larynx. In one, 
this organ is a complex muscular vocal apparatus; in the other the singing parts 
are less developed, rudimentary, or wanting. In the first, likewise, the tarsus is 
normally covered on either side with two entire horny plates, that meet behind 
in a sharp ridge; in the other, these plates are subdivided or otherwise differently 
arranged. This latter is about the only external feature that can be pointed out 
as of extensive applicability ; and even this does not always hold good. For 
example, among our birds, the larks (Alaudide), held to be Oscine, and certainly 
to be called songsters, have the tarsus perfectly scutellate behind. 
Suborder OSCINES. Singing Birds. 
The first and higher of the two suborders just indicated. All of the birds com- 
posing it have a more or less complex yocal apparatus, consisting of five pairs 
of muscles ; but many of them do not sing. 
It is a question, which one of the numerous Oscine families should be placed at 
the head of the series. Largely, perhaps, through the influence of those orni- 
thologists who hold that fusion of the tarsal envelope into one continuous plate 
indicates the acmé of bird-structure, the place of honor has of late been usually 
