438 



MANUAL OF ELEMENTARY ZOOLOGY 



these by any roof, and the nasal septum between them comes 

 down to divide it into two (p. 430). Over the soft palate it 

 is single, and is separated from the olfactory chambers by a 

 partition, supported by the horizontal flanges of the vomer, 



Fig. 321. — A vertical section through a rabbit's head. — From Thomson. 



pmx., Premaxilla with incisors ; //;.('., part of mesethmoid in front region, where 

 naria! passage is not separate from olfactory chamber ; n:.c'., part of same in 

 hinder region, where it divides from one another only the two olfactory 

 chambers, which are here separated by a horizontal partition from the single 

 narial passage (the intermediate part of the mesethmoid is cut away); t.t>., 

 maxillary turbinals ; (■./., ethmoidal turbinal ; ol/.L, olfactory lobe of cerebrum ; 

 /.v., presphenoid ; c.c, position of corpus callosum ; 6s., basisphenoid with 

 depression for pituitary body ; </'., cerebellum ; /'.,>., basioccipital ; s.c, spinal 

 cord ; »./., narial passage; g., gullet; tr., trachea; epg., epiglottis; smx., 

 submaxillary salivary gland; s./., sublingual salivary gland ; T., tongue;//., 

 transverse portion of palatine ; >>nt., anterior end of mandible. 



representing the true roof of the mouth. Into this hinder 

 part, the naso '-pharynx, open the Eustachian tubes. The 

 tonsils are a pair of pits at the sides of the soft palate 

 near its hind border. The tongue is an elongate, mus- 

 cular mass attached along most of its length to the floor 



