THE ALIMENTARY CANAL. 231 
Origin from the surface of the body of the sphenoid mediad 
of the groove for the Eustachian tube, from the styliform 
process of the bulla tympani, and in part from the Eustachian 
tube. The muscle passes caudad, and its fibres then diverge 
into the velum palatinum. 
Jnsertion into the velum palatinum, some of the fibres 
meeting in the middle line. 
.4ction indicated by the name. 
A number of other muscles have been described in the soft 
palate of the cat; they are, however, poorly developed and not 
easily distinguished. For an account of these, see Stowell, 
Proceedings of the Am. Soc. of Microscopists, 1889. 
2. The Pharynx.—At the caudal end of the mouth cavity 
the passage for the food and that for the air cross; at the 
cranial end the food-passage (mouth) is ventral, the respiratory 
passage (nasal cavity) dorsal. Farther caudad the food-passage 
(cesophagus) is dorsal, while the respiratory passage (larynx 
and trachea) is ventral. In the region of crossing there is 
therefore for a certain distance a common passageway for food 
and air, and this is known as the pharynx. It extends from the 
isthmus faucium, at the free caudal margin of the soft palate, to: 
the beginning of the cesophagus, at the dorsal or caudal margin 
of the opening of the larynx. The dorsal wall of the pharynx 
is separated from the base of the skull and the centra of the 
cervical vertebre only by intervening muscles (longus capitis, 
levator scapule ventralis, and longus colli, Fig. 72, page 
143). Its lateral and ventral walls are supported by the hyoid 
bone and the cartilages of the larynx. 
Craniad the pharynx continues, usually, without break into 
the cavity lying dorsad of the soft palate. But at the time of 
swallowing the free edge of the soft palate is pushed dorsad 
against the dorsal wall of the pharynx, while the caudal part 
of the pharynx is drawn craniad, so as to form a cavity con- 
tinuous with that of the mouth. In this way the cavity above 
the soft palate is completely separated at the time of swallow- 
ing from the rest of the pharynx. This separated portion is 
known as the nasopharynx: it is strictly a portion of the 
respiratory passage, as the food does not pass into it. The 
