THE CRANIAL NERVES AND SPECIAL SENSE ORGANS 95 
Floor of Mouth. —Note the kind and arrangement of teeth, 
the grinders (molars) in the posterior region and the cutters 
(incisors) in front, separated from the molars by a toothless 
interval. Note in connection with this, the complete absence of 
incisors in the upper jaw. 
Note the tall papillae, filiform in shape, of the tactile variety 
in the lining of the cheeks, and beneath the tongue. 
The Tongue .—Note its shape and extent. It is a muscular 
organ capable of taking a great variety of forms (cf. movements 
of your own tongue). The whole upper surface is thickly covered 
by papillae, the majority of which are minute and of the filiform 
variety, tactile in function. Among these are distributed the 
true taste papillae of the fungiform type, small in the distal region 
of the tongue but very large in the proximal. Along each side 
of the tongue in the proximal half, find a double row of large 
papillae of a third type, the circumvallate, consisting of an elevated 
circular center, with a furrow surrounding it and a circular ridge 
surrounding the whole. Connected with the posterior part of 
the tongue, note the presence and position of the epiglottis, which 
guards the glottis, the orifice of the larynx. Locate by palpation 
the hyoid bone which forms the skeletal support of the tongue; by 
dissection demonstrate the median part, or body, of the hyoid and 
two pair of cornua, and note that the lesser cornua are attached 
to the skull by a series of ligaments, and cartilages or bones (cf. 
the styloid processes of the human skull), while the greater are 
attached by ligaments to the thyreoid cartilage of the larynx (cf. 
dissection of the latter, pp. 98-100). 
Draw a view of the floor of the month and the tongue. 
