194 MANUAL OF MODERN FARRIERY. 



e. The frontal bone ; the cavities or cells below which are called 



the frontal sinuses. 

 /. The zygomatic arch. 

 g. The super-orbital foramina. 

 h. The lachrymal bones. 



i. The orbit which contains the eye. 

 k. The nasal bone. 



/. The superior maxillary bone. 

 m. The infra-orbital foramina. 

 n. The opening into the nose. 

 0. The inferior maxillary. 

 p. The upper incisors or cutting teeth. 

 qy qy q. The molars, or grinders of the upper and under jaw. 



r. The posterior maxillary or under jaw. 



t. The lower portion of the under jaw. 

 u. The under incisors, or cutting teeth. 



SECTION EXHIBITING THE INTERNAL ANATOMY OF 

 THE HEAD. 



PLATE III. Fig. 3. 



a. The occipital bone. 



b. The frontal bone, under which are cavities called the frontal 

 sinuses, marked 16, 16. 



These frontal sinuses are cavities intervening between the 

 frontal bone and a transverse plate of bone which grows 

 within it. They communicate with the cavities of the nose, 

 as also with those of the sphenoid, ethmoid, and upper jaw- 

 bones. In consequence of this conformation, they increase 

 the loudness and clearness of neighing. It sometimes hap- 

 pens that the larvas of certain flies crawl up the nostrils 

 and locate themselves in the frontal sinuses, occasioning 

 great pain to the animal. Happily, this is not of very fre- 

 quent occurrence with the horse, although sheep and horned 

 cattle are more liable to such intrusion. 



Some veterinary surgeons have made these sinuses a 

 medium to discover whether horses mth a running at the 



