CoGHiLL, Cranial Nerves of Anibly Stoma. 231 



with the most dorsal and mesial fibers of the general cutaneous 

 component of the infra-orbital trunk but is entirely distinct 

 from this component as this nerve leaves the ganglion. It fol- 

 lows along at first the anterior, and then the dorsal side of the 

 infra-orbital nerve, but inclines more dorsad than the latter and 

 passes to a subcutaneous position over the border of the m. 

 temporalis. As it approaches the skin it divides. Each of its 

 two divisions soon fuses with a twig from the infra-orbital trunk. 

 One of the nerves thus formed passes nearly to the mid-dorsal 

 line and innervates the skin over the ear capsule. The other 

 nerve passes to the skin farther cephalad. It meets a twig from 

 the r. ophthalmicus superficialis VII, but seems to separate from 

 it intact. 



The second accessory twig of the trigeminus arises from the 

 general cutaneous component of the infra-orbital nerve as this 

 component unites with the lateralis component to form the 

 main trunk. It is compressed for a short distance against the 

 posterior side of the infra-orbital nerve, but soon turns latero- 

 caudad dorsally of the lateral portion of the ear-capsule. It is 

 distributed to the skin over the proximal portion of the squa- 

 mosal bone. 



V. The Glossopharyngeus and Vagus. 



A. THE ROOTS AND GANGLIA. 



The ninth and tenth nerves arise by five roots which enter 

 a common ganglionic complex at the posterior end of the ear 

 capsule. The parts of this complex which belong to the dif- 

 ferent roots are very closely compressed together and it is not 

 always possible to determine the dividing lines between them. 

 By a study of several sets of serial sections cut in various planes 

 I have determined the mutual relations of the different ganglia 

 and the course of nearly all the components through them. The 

 motor components of the different roots were traced especially 

 in a preparation where the motor and lateralis fibers alone were 

 well medullated. As no motor axones emerge with the lateralis 

 root, the motor components of the other roots, with one ex- 



