THE HEAD. 



55 



such as the lachrymal gland and the membrana nictitans, are also contained 

 in this cavity. 



The temporal fossa surmounts the orbit, and is incompletely separated 

 from it by the orbital arch (or process). Oval in shape, lying obliquely fron 

 above to below, and from within outwards, on the sides of the cranium the 

 temporal fossa is limited, within, by the parietal ridge, and outwardly bv 

 the anterior border of the longitudinal root of the zygomatic process. It 

 lodges the temporal muscle. 



Base or superior extremity of the head. This presents the occipital pro- 

 tuberance, cervical tuberosity, occipital foramen, mastoidean ridge and fissures 

 styloid processes of the occipital bone, stylo-condyloid notches, and the con- 

 dyles. On a lower plane, and behind, the curved portion of the posterior 

 border of the maxillary bone is remarked. 



Summit. Formed by the premaxillary bones and the body of the super- 

 Fig. 26. 



LATERAL VIEW OF THE HORSE'S SKULL. 



1, Premaxillary bone ; 2, Upper incisors ; 3, Upper canine teeth ; 4, Superior 

 maxillary bone ; 5, Infraorbital foramen ; 6, Superior maxillary spine ; 7, Nasal 

 bones; 8, Lachrymal bone; 9, Orbital cavity; 10, Lachrymal fossa; 11, Malar 

 bone; 12, Upper molar teeth; 13, Frontal bone; 15, Zygomatic process, or arch; 

 16, Parietal bone; 17, Occipital protuberance; 18, Occipital crest; 19, Occipital 

 condyles ; 20, Styloid processes; 21, Petrous bone; 22, Basilar process; 23, 

 Condyle of inferior maxilla ; 24, Parietal crest ; 25, Inferior maxilla ; 26, Inferior 

 molars ; 27, Anterior maxillary foramen ; 28, Inferior canine teeth ; 29, Inferior 

 incisor teeth. 



maxilla, the summit supports the incisor teeth, and presents a tuberosity 

 more or less rounded, according to the age of the animal. In front, it is 

 surmounted by the external opening of the nasal cavities; this opening, 

 which is comprised between the external process of the premaxillary bones 

 and the nasal spine, is divided in the fresh state into two orifices which 

 constitute the nostrils. 



Internally, the head contains the nasal fossce and the cranial cavity. 

 These will be described when the apparatus belonging to them is noticed. 

 (See the respiratory and nervous apparatus). 



DIFFERENTIAL CHARACTERS OF THE HEAD IN OTHER THAN SOLIPED ANIMALS. 



A. HEAD OF THE Ox, SHEEP, AND GOAT. 1. Occipital lone. The occipital bone in 

 these animals docs not show any anterior elbow. The cervical tuberosity, or occipital 



