THE NASAL CAVITY 83 
behind, and the vomer below. In the fresh state it is completed by the cartilage 
of the septum nasi (Cartilago septi nasi). 
Fic. 55.—Cross-SecTION OF Nasat REGION OF SKULL Fic. 56.—Cross-SeEcTION OF NASAL REGION OF SKULL 
or Horse; THE Section Passes THROUGH THE oF Horse; THE Section 1s Cur Asoutr Hatr- 
ANTERIOR END OF THE Facrat Crest, AND BE- WAY BETWEEN THE ORBIT AND THE 
TWEEN THE THIRD AND FourTH CHEEK TEETH. END OF THE Facial 
a, Dorsal, 6, ventral, turbinate bone; c, d, cavities 
of a and b; e, common meatus; f, g, h, dorsal, middle, 
ventral meatus; i, k, passages 
bones; J, naso-lacrimal duct; 7 
anterior end of maxillary 
(After Ellenberger, in Leisering’s 
The turbinate bones divide each half of the nasal cavity into three meatus 
nasi. 
The dorsal meatus (Meatus nasi dorsalis) is a narrow passage between the 
roof and the dorsal turbinate bone. It ends at the cribriform plate of the ethmoid. 
Fie. 57.—SxKvcit or Younc Horse; Laterat View, WITH Srnuses OPENED UP. 
A’, A, Anterior and posterior compartments of maxillary sinus; B, B’, frontal and turbinate parts of frontal sinus, 
C, orbit; septum between compartments of maxillary sinus; 2, 2, infraorbital canal; 3, turbinate part of maxillary 
sinus; 4, 5, 6, last three cheek teeth (covered by thin plate of bone); 7, anterior limit of maxillary sinus in older subject; 
8, infraorbital foramen; 9, anterior end of facial crest; 10, course of naso-lacrimal duct; 11, fossa for lacrimal sac; 12, 
dorsal turbinate bone; 13, fronto-maxillary opening. 
The middle meatus (Meatus nasi medius) is the space between the two turbinate 
bones. In its posterior part is the very narrow opening into the maxillary sinus. 
The ventral meatus (Meatus nasi ventralis) is the channel along the floor which is 
