56 F. W. THYNG 



The auriculo-temporal has two roots of origin which em- 

 brace a branch of the stapedial artery. It extends at first 

 ventrally and laterally, and then bends dorsally, giving off 

 twigs to the epithelium, in the neighborhood of the tuberculum 

 tragicum. 



The inferior alveolar (N.alv.inf.) crosses the lateral border of 

 the pharynx, and follows the lateral side of Meckel's cartilage 

 beneath the pharyngeal floor. It soon gives off the mylohyoid 

 branch which passes ventrally, lateral to Meckel's cartilage, to 

 the anlage of the mylohyoid muscle. The inferior alveolar then 

 continues cephalad in the mandibular process of the mandibular 

 arch where it divides into a dorsal and a ventral branch. The 

 former supplies the oral epithelium of the corresponding side, 

 the latter or mental nerve supplies the ectoderm on the Ventro- 

 lateral surface of the mandibular process. 



The lingual nerve {N.ling.) is formed by the union of mandibu- 

 lar and chorda tympani fibers (Nxh.tymp.) medial to Meckel's 

 cartilage. It extends cephalad for a distance between the carti- 

 lage and the alveolo-lingual ridge where the submaxillary gland 

 {Gl.smx.) has developed. Here it passes into the anlage of the 

 submaxillary ganglion (plate 3). From the ganglion it issues as 

 several bundles which curve medially around the alveolo-lingual 

 ridge into the lateral part of the tongue. In this situation 

 branches extend cephalad between the ridge and the hypoglossal 

 nerve and, after repeated subdivisions, are ultimately distributed 

 to the epithelium of the tongue. 



N. abducens. The abducens (N.ab.) issues from the ventral 

 wall of the metencephalon (Meten.) by several rootlets which are 

 hidden in the drawings by the overlying auditory and facial 

 nerves. A caudal aberrant root is present on either side which 

 extends from the region of the glossopharyngeal and vagus 

 nerves to join the abducens. Similar aberrant roots of the 

 abducens have been observed by Elze ('07) and represented by 

 Bremer ('08). The abducens extends ventrally and somewhat 

 laterally towards the orbital region. It passes dorsal to the in- 

 ternal carotid artery, obliquely across the medial side of the 

 cavernous sinus and ophthalmic vein. The abducens then turns 



