312 ANATOMY OF THE RABBIT 



developed on the softer anterior part of the tongue, where 

 single minute low elevations, the fungiform papillae, are 

 scattered among them. At the posterior end of the smooth 

 portion, there are on either side a minute spherical ele- 

 vation, set low into the mucous membrane, the vallate 

 papilla (papilla vallata), and in a more lateral and anterior 

 position an oval area, the papilla foliata, the surface of 

 which is marked by fine parallel ridges. Microscopic taste 

 buds occur on the fungiform and, especially, on the vallate 

 and foliate papillae. 



In the pharynx: 



(a) The tonsils (tonsillae palatinae) are a pair of rounded masses 

 of lymph follicles each lying on the anterior wall of a deep 

 lateral depression, the tonsillar sinus (sinus tonsillaris). 

 The vertical slit-like aperture of the sinus is bounded by 

 low anterior and posterior folds. 



(b) The epiglottis, a valve-like fold guarding the entrance to 

 the larynx, projects upward from the floor into the pharyn- 

 geal cavity, past the edge of the soft palate. 



(c) By removing the posterior portion of the soft palate, the 

 connection of the nasopharynx with the nasal fossae will 

 be exposed. Also, on the lateral wall of the nasopharynx, 

 there will be visible the pharyngeal aperture of the auditory 

 tube (ostium pharyngeum tubae), the other end of which 

 opens into the middle ear. 



10. Examination of the larynx. 



By cutting around the base of the tongue on the opposite side 

 of the body, the whole structure, together with the hyoid, larynx, 

 and a portion of the trachea back to about the end of the thyreoid 

 gland may be removed. This affords a good opportunity of re- 

 dissecting on the opposite side from the medial surface of the man- 

 dible outward. The hyoid apparatus, which supports the base of 

 the tongue, should be cleared and examined (see p. 197). 



The small, unpaired, median vertebral vein may be observed on the ventral 

 surfaces of the vertebrae. This vessel, formed anteriorly by the veins of the 

 nasal septum, receives a tributary through the foramen cavernosum from the 

 basisphenoid bone, is joined by paired vertebral veins, and empties into the 

 posterior end of the external jugular vein of either the right or the left side. 



