424 



DIGESTIVE SYSTEM OF THE DOG 



eight to ten curved ritlges on either side of the rai:)he. Behind the first pair of 

 incisor teeth is the triangular incisive papilla, at which the naso-palatine ducts 

 open. The mucous membrane is usually pigmentetl. 



The soft palate is thick except at its margins. In the resting state of the parts 

 it comes in contact with the oral surface of the epiglottis. Between its anterior 

 and posterior ])illars on either side is a marked tonsillar sinus, in which an elongated 

 tonsil is situated; this is retldish in color, about an inch long, and projects somewhat 

 into the fauces between two folds of mucous membrane. 



The tongue is wide, thin, and very mobile. It is not pigmented, but has a 

 bright red color. The upper surface is marked by a median groove (Sulcus medi- 

 anus linguae), and is thickly beset with short, pointed, filiform ])apilhr, the free ends 

 of which are directed ])ackward. On the root the papillae are long and soft; 

 similar papillse occur on the lateral walls of the isthmus faucium. The fungiform 

 papilla; are small, and are scattered over the dorsum and sides of the tongue, l)ut 

 are absent on the root. There are usually two or three vallate papilla? on either 

 side. Small foliate papillse are also present. In the inferior part of the tip of the 

 tongue is the lyssa, a fusiform cord, composed of fibrous tissue, muscular tissue, 

 and fat. In large dogs it is about two inches (ca. 4 to 5 cm.) long. 



Fii;. 327. — Skull ok Adui.t St. liiouNAHi) Dog, Srui.PTUREn to Show tiik F.mbeddei) Parts of the Tketh. 

 ll-d, Iiuisors; (', canines; Pl-4, premolars; Ml-S, molars. 



THE TEETH 

 The formula for the permanent teeth is : 



(3 1 4 2 \ 

 I-C-P- M - I 

 3 14 3 / 



