(chiefly) a bone called the intermazxillary, or better, 
OF THE BILL. 23 
Sub-sect. 2. Of the Members; their parts and organs. 
ihe Mesos a sinage 
§ 42. Tuer Birt is hand and mouth in one: the instrument of prehension. 
As hand, it takes, holds and carries food or other substances, and in many 
instances, feels; as mouth, it tears, cuts, or crushes, according to the nature 
of the substances taken; assuming the functions of both lips and teeth, 
neither of which birds possess. An organ thus essential to the prime funce- 
tions of birds, one directly related to their various modes of life is of the 
utmost consequence in a taxonomic point of view; yet, its structural modi- 
fications are so various and so variously interrelated, that it is more impor- 
tant in framing families and genera than orders; more constant characters 
must be employed for the higher groups. The general 
§ 43. Suapn of the bill is referable to the cone; it is the anterior part of 
the general cone that we have seen to reach from its point to the base of the 
skull. This shape confers the greatest strength combined with the greatest 
delicacy ; the end is fine to apprehend the smallest objects, while the base is 
stout to manipulate the largest. But in no bird is the cone expressed with 
entire precision; and in most, the departure from this figure is great. The 
bill aLways consists of two, the upper and the lower 
§ 44. Manprpezes (fig. 5), which lie, as their names indicate, above and 
below, and are separated by a horizontal fissure —the mouth. Each mandi- 
ble aLways consists of certain projecting skull-bones, 
sheathed with more or less horny integument in lieu of 
true skin. The frame-work of the Upper mandible is 
abcde f £ 
in this case, the premawillary. In general, this is a 
three-pronged or tripodal bone running to a point in 
front, with one, the uppermost prong, or foot, im- ; 
1 k j i 
planted upon the forehead, and the other two, lower "Pig. 5. eae ee 
and horizontal, running into the sides of the front of  a,siae orupper mandible; 6, cul- 
en; c, nasal fossa; d, nostril; e, 
A . ™m 
the skull. The scaffold of the Under mandible is a (Gee beiow); 7 gape, or'whole com> 
missural line; g, rictus; h, commis- 
compound bone called inferior maxillary; it is U-, or sural pointor angle oF tne ont 
i, pais of under jaw; j, tomia of 
: . . . andi t reference 
V-shaped, with the point or convexity in front, and tines’ should have been drawn to 
indicate the corresponding tomia 
the prongs running to either side of the base of the of upper mandible); t, angle of 
gonys; /, gonys; m, side of under 
skull behind, to be there movably hinged. These two Mules” HPs of mandibles. 
bones, with certain accessory bones of the upper mandible, as the palate 
es, etc., together with the horny investment, constitute the 7s. p 
bones, etc., togeth th the | t ie titute the Jaws. Both 
jaws, in birds, are movable; the under, by the joint just mentioned; the 
upper, either by a joint at, or by the elasticity of the bones of, the forehead ; 
it is moved by a singular muscular and bony apparatus in the palate, 
further notice of which would involve anatomical details. When closed, 
the jaws meet and fit along their opposed- edges or surfaces, in the same 
manner, and for the same purposes, as the lips and teeth of man or other 
