166 DISSECTION OF THE DOG 



common with the tensor and crosses the medial surface of the pterygo- 

 pharyngeal muscle to reach the soft palate. 



M. pterygo-pharyngeus. — The pterygo-pharyngeal muscle has its origin 

 from the hamulus of the pterygoid bone, from which it passes in a caudal 

 direction to reach the raphe of the pharynx. 



M. rHAEYNGO-PALATiNUS. — Partly blended with the foregoing, the fibres of 

 the pharyngo-palatine muscle stretch from the free border of the palatine 

 bone to the pharynx. 



M. jugulo-hyoideus. — If sufficient care be exercised, the very small 

 iugulo-hvoid muscle may be discovered crossing the narrow interval between 

 the jugular process of the occipital bone and the cartilaginous connection 

 of the stylo-hyal with the temporal bone. 



M. STYLO-PHARYNGETT3. — The stylo-pharyngeal muscle arises from the 

 proximal part of the stylo-hyal bone, and terminates, under cover of the 

 hyo-pharyngeal muscle, in the wall of the pharynx. 



M. hyo-pharyngeus. — The hyo-pharyngeal muscle consists of two parts, 

 both of which end in the wall of the pharynx : (1) The more superficial part 

 of the muscle (m. chondro-pharyngeus) is much the more extensive, and arises 

 from the thyro-hyal bone and possibly also from the adjacent portion of the 

 hypo-hyal ; (2) the deeper part of the muscle (m. cerato-pharyngeus) is in 

 the form of a narrow band springing from the cerato-hyal bone. 



M. thyPvEO-phaPvYngetjs. — The thyro-pharyngeal muscle passes from 

 the oblique line on the lamina of the thyroid cartilage to the raphe of the 

 pharynx. 



M. crico-pharyngetjs. — Disposed in the same manner as the foregoing, 

 the crico-pharyngeal muscle arises on the lateral surface of the cricoid cartilage. 



M. cerato-hyoideus. — To display the cerato-hyoid muscle properly it is 

 necessary to reflect the hyo-pharyngeal muscle. When this has been done a mass 

 of muscular fibres will be found attached to the whole length of the thyro- and 

 hypo-hyal bones and the adjacent part of the cerato-hyal. 



N. glosso-pharyngeus. — The glosso-pharyngeal or ninth cerebral nerve 

 leaves the cranium by the jugular foramen and soon divides into two branches : 

 (1) The Ungual branch (ramus lingualis) is much the larger, and, crossing the 

 lateral surface of the stylo-pharyngeal muscle, passes between the stylo-glossal, 

 stylo-pharyngeal, and hyo-pharyngeal muscles to reach the mucous membrane 

 of the tongue ; (2) the pharyngeal branch (ramus pharyngeus) is much smaller 

 and is joined by a twig from the superior pharyngeal branch of the vagus nerve. 



N. vagus. — The vagus or tenth cerebral nerve comes out of the cranium by 

 way of the jugular foramen in company with the glosso-pharyngeal and accessory 

 nerves. Two ganglia augment the volume of the nerve at different points. 

 The jugular ganglion (ganglion jugulare) is formed on the nerve while it is within 

 the jugular foramen ; and the nodose ganglion (ganglion nodosum) when it 

 has become free from the cranium. The latter ganglion is long and fusiform, 



