MOUTH OR BUCCAL CAVITY. 303 



(A, II, 301), to be merely an aggregation of buccal glands ; see 

 794. 



786. G-landula zygomatica Zygomatic, subzygomatic or in- 

 fraorbital gland. This is a compact, somewhat elongated gland 

 situated in the lateral part of the orbit. Its ventral end rests on the 

 mucous membrane of the roof of the mouth just caudad of the last 

 maxillary tooth (true molar, see Fig. 57, D. M.), and its duct opens 

 at the same place. 



787. To demonstrate this gland, the mouth may be kept open 

 by a cork between the teeth ; then the mucous membrane just caudad 

 of the last maxillary tooth should be cut, and the gland will appear. 

 Or the zygoma, the malar process of the maxilla and the masseter 

 muscle may be removed to expose the lateral surface of the eye- 

 ball. The gland will be found at the ventro-lateral surface of the 

 eye. To demonstrate its duct, carefully tear away the gland sub- 

 stance near its ventral end with a tracer. 



788. Structure of Salivary Glands. The obvious structure of the salivary glands 

 is that of the racemose type, that is, like a bunch of grapes, the ducts representing the 

 stems and the lobules the fruit. 



789. Microscopic Structure. The ducts, except the very smallest, are lined with 

 columnar epithelium ; the smallest are lined with pavement epithelium. Their mode of 

 termination "demands further investigation" (Strieker, A, 800). The lobules are com- 

 posed of groups of spheroidal cells surrounded by a continuation of the connective tissue 

 forming the interlobular septa. Quain, A, II, 339. 



CAVUM ORIS, MOUTH OR BUCCAL CAVITY, PHARYNX, az. (Fig. 77, 88). 



References. Quain, A, II, 300; Gray, A, 745 ; Chauveau, A, 351 ; Chauveau (Flem- 

 ing), A, 330 ; Leyh, A, 364; Owen, A, III, 388 ; Ouvier, A, III, 379 ; Hyrtl, A, 241 ; Ge- 

 genbaur (Lankester), A, 548 ; Milne-Edwards, A, VI, 11 ; Gurlt, A, 3^6. 



790. The mouth cavity or cavum oris is the cephalic division 

 of the alimentary canal. It is bounded cephalad by the lips and 

 caudad by the velum palati and the cephalic opening of the pha- 

 rynx. It contains the teeth, gums, alveolar margins, the jaws, the 

 tongue and the tonsils, and into it open the ducts of the salivary 

 and buccal glands. 



791. Pharynx, az. See description of Fig. 88. 



Exposure and Dissection Fig. 88. With a scalpel, divide the 

 skin and soft parts upon both the dorsal and the ventral aspects of 

 the head 1 cm. sinistrad of the meson from the snout to a point 

 opposite the 2d or 3d cervical vertebra. With the arthrotome, sep- 

 arate the mandibular rami at the sympJiysis menti, and with bone 



