9 
PROF. W. K. PARKER ON “GITHOGNATHOUS BIRDS. 2093 
The fledgeling shows how ichthyic the maxillaries remain, even in this high type 
(fig. 1, mx); they wedge in below the dentary and palatine processes of the premaxil- 
laries, and then, growing broader, send inwards the great slanting spatulate maxillo- 
palatine spur (ma.p). This has a struthious coarseness now, but becomes elegant in its 
curves and scoopings afterwards (fig. 6), and acquires a distinct pedicle. That pedicle is 
much more slender and defined in many of the feebler forms that crop up around the 
true “ Corvide ;” and its form, ruder or more elegant, is very useful as a mark of high 
or low breeding in any type. The long jugal style (7) has no quadrato-jugal subdivision, 
but binds directly on the quadrate. 
This latter bone and its relationships, although not coming within my stricter plan, 
has to be brought in here. It curves backwards (fig.7, g) to be articulated with a raised 
facet common to the periotic and exoccipital regions: this “ otic process” is merely the 
expression, morphologically, of the hooked form of the proximal end of every facial bar ; 
its orbital process is the “ pedicle” or apical process (pd). 
Here, in the bird, instead of being enclosed in the tympanic cavity, it forms its cres- 
centic anterior wall and boundary, and to it the rim of the membrana tympani is largely 
attached. Our ancestors called the quadrate the “tympanic”’; but younger eyes have 
beheld the true tympanic in another form: here it is seen divided into a fine chain of 
bones, seven in all; one of the seven, the largest, has a side duty imposed upon it, 
namely the walling-in of the “siphonium.” ‘This tube (fig. 1, spm) is membranous in 
the fledgeling; but afterwards in the Corvide, and in many of the singing-birds, the 
principal tympanic is coiled upon itself, the opposite edges uniting; thus the tube is 
quite enringed. 
My demonstrations of these parts are from an old Carrion-Crow (Corvus corone); this 
is the example mentioned by Prof. Huxley (Elem. Comp. Anat., note to p. 249) as 
haying six tympanics, as I had then informed him. 
In fig. 7 the bone attached to the jugal (j) and that behind the articulare are “ sesa- 
moids” (sd) in the “ external quadrato-articular ligament ;” but the more massive bone 
running downwards from the tympanic ring to the upper surface of the “internal 
angular process” of the mandible is the “os siphonii” or principal tympanic. 
In fig. 8 the pneumatic passage into the lower jaw is shown, a bristle passing into 
it; in fig. 9 the bristle passes also through the lower third of the insheathing tympanic, 
which is seen to be folded upon itself. Fig. 9@ is the upper or tympanic end of the 
bone, its edges perfectly closed in, forming an oval aperture. In the Crocodile (see 
Huxley, “On the Representatives of the Malleus and Incus,” Proc. Zool. Soc. May 27, 
1869, p. 391) the siphonium carries air from the quadrate into the articulare—but in 
the bird, from the tympanic cavity, as Nitzsch has rightly described it. 
Correlated with the compound vomer, attached to the nasal vestibule, we have, with 
‘ This fine old race of teleological anatomists is nearly extinct; only Owen remains of the remnant of the 
giants. 
