226 Journal of Comparative Neurology. 



frequently come in contact with each other but they never 

 anastomose. The trigeminal branch innervates the skin along 

 the lateral aspect of the mandible, and extends nearly to the tip 

 of the chin. It tends to lie more ventrally of the mandible in 

 the distal part of its course. 



The mandibular trunk now follows the dorsal border of 

 Meckel's cartilage for a short distance cephalad. It then gives 

 off the fourth cutafieoiis branch (indb.^) which continues the 

 course of the main nerve, sending fibers to the neighboring 

 skin, and at length becomes enclosed in a canal between the 

 dentary bone and Meckel's cartilage, Within this canal it 

 gives off fibers w^iich probably terminate in the teeth. It anas- 

 tomoses by one twig with the r. alveolaris VII, and w^ith an- 

 other passes out of the canal and becomes subcutaneous along 

 the lateral margin of the mandible. The latter twig innervates 

 the skin of the under lip to the symphysis mentis. 



The remainder of the mandibular nerve turns ventrad from 

 the last point of branching, and passes between the angular bone 

 and Meckel's cartilage. It then passes mesad ventrally of the 

 mandible and soon breaks up into three divisions. Two of these 

 divisions, the most anterior and the most posterior one, contain 

 both motor and general cutaneous fibers. The middle division 

 contains only general cutaneous fibers. Various twigs from 

 these divisions anastomose with one another, but there seems to 

 be no constant arrangement in this regard. An anastomosis 

 between a terminal twig of the posterior division and the ter- 

 minal fibers of the r. jugularis VII seems to be constant. The 

 fibers united in this manner almost immediately enter the m. 

 interhyoideus. The other motor fibers of the mandibular V 

 in the lower jaw are distributed to the m. mylohyoideus; the 

 cutaneous fibers to the skin ventrally of this muscle. It is a 

 noticeable leature of these nerves that they always lie on the 

 ental side of the lateral line nerves of the same region. 



J. — The Truncns Hyomandibularis. 



The hyomandibular trunk of the facialis passes laterad from 

 the geniculate ganglion through the large foramen in the base 



