304 ANATOMICAL TECBNOLOGT. 



scissors, cut tlie left pier of the os hyoides (Pig. 30, § 234). Hemisect 

 the tongue and the muscles along the ventral side, cutting about 

 1 cm. to the left of the meson and entirely through to the buccal 

 €avity. The trachea and oesophagus should be displaced to the 

 right. Cover the hand with a towel and grasp the left side of the 

 head, and divide the entire head with the saw, commencing at the 

 snout a little sinistrad of the meson and making the strokes in the 

 dorso-ventral rather than in the caudo-cephalic direction. With 

 nippers, remove the left side of the vertebral arch of the atlas, axis 

 and the sJcull as far as the meson. 



§ 792. K a permanent preparation is to be made, the remaining 

 half of the mandible should be opened and a cork put between the 

 teeth ; the tongue should be drawn slightly cephalad and held in 

 position by a pin pushed through its tip and into the floor of the 

 mouth. The velum palati may be pinned out as in the figure. 

 PinaUy, the oesophagus and larynx should have one side cut away 

 for a short distance and the tubular portion distended by filling the 

 lumen with cotton ; the opening of the Eustachian tube should also 

 be fiUed with cotton. 



Begin the hardening in about 60 per cent, alcohol (§ 286). After 

 the head has thoroughly hardened, the brain may be sliced away 

 to the meson, and the mesefhmoideum and vomer removed to show 

 the turbinated bones and the passage from the prsenaris to the post- 

 naris. The surface, especially of the tongue, may be freed from 

 mucous with a soft nail brush. 



§ 793. Oivious Structure of the Oavum oris or Mouth. — The free surface is usually 

 -quite firm and smootli, except in certain places, as the roof of the mouth, where there axe 

 many ridges and fine projections. 



§ 794. Mieroicopic Structure. — The free surface is made up of stratified epithelium rest- 

 ing on a rather abundant submucous connective tissue, in which are small so called buccal 

 glands of the racemose type (§ 178), whose ducts open on the free surface. 



§ 795. Gbmovs Structure of the Lingua or Tongue. — The free surface on the ventral 

 side of the tongue is smooth and soft. On the dorsal side it is beset with numerous pro- 

 jections or papill(B of various forms, named in the order of their abundance : — Filiform, 

 odontoid, fungiform, circumvallate. 



§ 796. Microscopic Structure. — Into all the papillae extend loops of blood vessels. 

 The odontoid variety are covered by a horny substance. In the walls of the circumvailate 

 are imbedded the so called taste buds, flask-like in form and composed of modified epithe- 

 lium. The principal mass of the tongue consists of striped muscle and connective tissue. 

 The muscles are arranged in an intricate net-work, the fibers sometimes branching near 

 the mucous coat. The free or mucous coat consists of stratified epithelium with a small 

 .amoimt of submucous connective tissue. See Strieker, A, 352 ; Quain, A, II, 337. 



