The lower half of the mouth lies between the lower jaw bones and the walls of the mouth cavity. The tongue is attached here by means of the phrenum (Fig. 27, No. 8). This half of the mouth forms a pocket-like structure which aids in taking up the food. The mouth cavity is lined with stratified squamous epithelium, continuous with that of the pharynx and the esophagus. Taste buds are located in the mucous membrane of the mouth. [Illustration: FIG. 28.—Various anatomical parts of the fowl. _C._ A section through the nasal region of the fowl. 1, Nasal passages showing the turbinated bones dividing the nasal passage into the superior, middle and inferior meati. 2, The infraorbital sinus. 3, The hard palate. _D._ Herbst’s touch corpuscle from the beak of a quail. _E._ A vertical section through the ductus cochlearis of a pigeon. 1, A blood-vessel. 2, The periosteum. 3, The bony structure. 4, The vascular integument. 5. The scala vestibuli. 6, The inner hyaline cylindrical cells. 7, The membrana tectoria. 8, The papilla acustica basilaris. 9, The membrana basilaris. 10, The scala tympani. 11, The ganglion of the cochlear nerve in the ramus basilaris. 12, The periosteum (Gadow). _F._ A corpuscle of the soft papilla of a duck’s tongue. _J._ A transverse section through a feather papilla. 1, The pulp. 2, The malpighian layer. 3, The corium. 4, The stratum corneum of the papilla. 5, The malpighian cell group of the main shaft. 6, The horny sheath. ] In many water fowls, as geese and ducks, the gum edge of the mandible has grooves extending crosswise, in which are numerous terminals of the trigeminus nerve arranged as taste organs (Fig. 29, _G_ and Fig. 28, _D_ and _F_). In many birds of prey and in water birds, _e.g._, the goose and the duck, there is found at the base of the beak, a very thin, nervous or sensitive skin, waxy in appearance, called the ceroma. [Illustration: FIG. 29.—Various anatomical parts of the fowl. _A._ 1, The superior semicircular canal. 2, The vestibular nerve. 3, The meatus auditorius internus—the entrance of the auditory nerve. 4, The entrance of the cochlear nerve. 5, Posterior semicircular canal. 6, The ampulla. _B._ Side papilla of the tongue. 1 and 2, Papillæ showing a fibrous central core supporting blood-vessels and nerves. 3, The basement membrane consisting of connective tissue. _G._ Herbst’s corpuscle of the tongue of a duck, showing the capsule, lamella and around the nerve zone, numerous round bodies arranged in two rows. _H._ From the cristæ acoustica of the ampulla of the dove. A, A vertical section with isolated fiber cells. 1 and 2, The nerve fibers. 3, The hair cells.