Fig. 21. 



46 '////: 



opens into tho incisive foramen. These three faces are separated by as 

 many border*: tiro internal, limiting before and behind the e-orresponding 

 face ; and an external, separating tho labial from tin buccal face. The latter 

 only merits notice ; it is very thick, and is divided into two parts : uu 

 inferior, which describes a curved lino with tho concavity upwards, and 

 is hollowed by three alveoli to receive tho incisor teeth ; another, tin- 

 superior, is straight, vertical, and somewhat sharp, and forms a part of 

 the dental interspace. It is limited above, near the base of the external 

 process, by a cavity for tho formation of the alveolus of the tusk. 



Processes. These are distinguished as ex- 

 ternal and internal. The first, the longest and 

 strongest, is flattened on both sides ; its ex- 

 ternal face is smooth and continued with that 

 of the thick portion of the bone; its internal 

 face is covered by tho mucous membrane of 

 the nose ; the anterior border is smooth and 

 rounded ; the posterior, denticulated to re- 

 spond to the supermaxillary bone, is in con- 

 tact with the external border of the base ; its 

 summit is thin, and is insinuated between tho 

 latter and tho nasal bone. The ////< run/ i<n>- 

 cess, the smallest, is flattened from before to 

 behind, and forms a very thin tongue of bone, 

 separated from tho other portions by a nar- 

 row and very deep notch named the incixire 

 opening or cleft. Its inferior face constitutes a 

 small portion of the floor of tho nasal fossae ; 

 the posterior, continuous with the same face 

 of the principal mass of tho bone, forms part 

 of the palatine roof; its external border cir- 

 cumscribes, inwardly, the incisive opening ; 

 the internal is united by dentated suture with 

 the opposite bone. 



Structure and development. It is a spongy 

 bone, developed from a single nucleus. 



3. Palate Bones. 



Tho palate bones are situated between the 

 supermaxillarics, at tho margin of tho guttural 

 opening of tho nasal cavities, and are articu- 

 lated with the sphenoid, othmoid, vomor, 

 frontal, and pterygoid bones. Elongated from 

 1, Occipital protuberance; 2, above to below, flattened laterally, and curved 

 Foramen magnum ; 3, 3, Oc- 

 cipital condyles; 4, 4, Styloid processes; 5, 5, Petrous bone; 6, Basilar process; 7, 

 Pterygoid fissure of the sphenoid bone; 8, Foramen laivrum : !'. ", Supra-coiuiyb.iil, or 

 anterior mastoid process; 10, 10, Articular eminence, or tempi**. ,i eomlyle; 11, llody nt 

 sphenoid bone; 12, Pterygoid process; l.'t, Ktlmioid bone; 14, Temporal bone and sphe- 

 noidnl suture; 15, Lachrymal bone; 14$, Vomer; 17, Malar bone; 1H, Maxillary ttibe- 

 rosity; 19, Posterior, or guttural o|x*nin<r of tin- nose; -ju. Palate bom-; _'!. Palatine 



I'alatine process of .superior ma\il- 

 iry bone; 25, Premaxillary bone; I'll, 

 prcmaxillary with the superior maxil- 

 lary bone; 28, Upper molar teeth young mouth 



POSTERIOR ASPECT OF HORSE'S 

 8KUI.I.. 



rosity; IV, 1 ostenor, or guttural opening 01 HM n 

 styloid process ; 22, Palate-maxillary foramen; _:;. 

 lary bone with suture; 24, Ditto of premaxillary 

 Upper incisor teeth; 27, Point of junction of the' pn 



