ANATOMY OF THE SALIVARY GLANDS IN THE CARNIVORA 1 59 



Of the cat and dog about fifty individuals of each were examined. 

 Of these only five in each species were studied statistically, and that 

 solely with reference to the occurrence of accessory parotid lobules. 



FELIS DOMESTICA 



The vestibule and cavum oris proprius communicate caudad to the 

 teeth by a triangular orifice, bounded dorsad by fibers of the masseter, 

 wliich arise from the maxillary tuberosity, caudoventrad by the border 

 of the mandibular ramus, and craniad by the last premolars. The 

 masseter further overhes the vestibular end of this passage, which it 

 assists in closing when contracted. The closure depends in addition 

 upon temporary-folds of the adjacent mucosa, which appear when the 

 jaws are approximated, and a small permanent plica attached to the 

 mandible (Figs, i and 2, 43). This is sagittally directed and extends 

 from the border of the ramus, increasing in height to the mesal side of 

 the last premolar. When the mouth is shut its cranial end fits into 

 and fills the space between the last upper premolar and the rudimen- 

 tary molar, while farther caudad its crest enters a groove (Fig. 2, ^5) 

 at the mesal border of the masseter. This furrow, corresponding to 

 the functional separation of vestibule and cavum oris, it is convenient 

 to take as a formal boundary between the two cavities. It extends 

 from the border of the mandibular ramus to the maxilla near the 

 molar tooth (42). Ventrad it intervenes between the masseter and 

 internal pterygoid (30, 32). Dorsad the muscles separate, exposing a 

 triangular area (46) where the bodies of the orbital glands and infra- 

 orbital fat are in contact with the mucous membrane, which appears 

 paler in consequence, unless the cat happens to be either pure white 

 or black. On account of its relation to the orbital glands, it may be 

 termed the glandular trigone. Along its lateral border open the ducts 

 of the caudal members of this series (/j), and close to the maxilla the 

 deep facial vein (34) is seen at its lateral angle. The division here 

 proposed between vestibule and cavum oris proprius in the postdental 

 segment of the mouth, looks merely to precision and convenience of 

 description. In reality we are dealing with a region in which this 

 differentiation, which depends on the presence of the teeth, has not 

 occurred. Its small morphologic significance is shown by the fact 



