2i6 Journal of CoMi'AKy\Ti\E Neuhology. 



springs from the base of V- very near its origin and passes 

 cephalo-dorsad through a separate foramen, F;, thence laterad 

 to the opercle, superficially. Before entering its foramen it 

 sends a very small tv^^ig cephalad to ramify in the frontal 

 bone near the median line. V; is one of the largest 

 separate branches of the fifth nerve. Its apparent origin is 

 not from the medulla, but from the roots of the other 

 divisions. It passes dorso-caudad through a foramen, F4, 

 situated over the caudal end of the medulla, thence caudad 

 superficially near the median line the entire length of the 

 body. It appears to partake of the function of the nerve of 

 the lateral line. Gasser's ganglion is obviously developed on 

 this branch alone. The microscope, hov^^ever, shovs^s elon- 

 gated bands of ganglion cells between the strands of the 

 other branches also. Tlie sixth nerve could not be separately 

 distinguished. The auditory nerve springs from the medulla 

 immediately caudad of the trigeminal by several roots which 

 are united into a broad, flat band. The cephalic and caudal 

 portions supply the semi-circular canals, the middle portion 

 the otolithic sac. 



In the vagus group the ninth and tenth nerves are quite 

 distinct. The ninth arises immediately caudad of the eighth 

 and closely associated with it. After sending a branch to 

 communicate with the ventral root of the vagus it divides, 

 one branch going to the opercle, the other to the first gill. 

 One or two small branches arise near the medulla and pass 

 caudad. Their connections were not discovered. The tenth 

 arises by two large roots, dorsal and ventral, which combine 

 into a ganglion outside the foramen. Cephalad, there branch 

 oft' from this ganglion nerves to the several gills, one branch 

 to the first and second, another to the second and third, and 

 another to the third and fourth. Each gill thus receives two 

 distinct nerves. Passing caudad, there is a large branch 

 which divides, one portion supplying the levator of the 

 pectoral fin, the other the depressor of the pectoral fin. 

 From the latter arises a small cutaneous branch to the post- 



