No. I.] THE CRANIAL NERVES OF AMPHIBIA. 109 



fibres scattered among them. As the different branches sepa- 

 rate from the main trunk they usually draw off several of these 

 larger fibres. The latter have apparently no special significance 

 as far as their peripheral distribution is concerned. They seem 

 to have the same cutaneous terminations as the smaller fibres. 

 Whether a more exhaustive study of them would reveal histo- 

 logical differences in their ultimate terminations, I do not 

 know. The presence of these large fibres in cutaneous branches 

 is readily accounted for by their presence also in the ascending 

 tract of the Trigeminus, in which they can be traced caudad to 

 the posterior columns of the cord. 



The other and dorsal division of the V .46 mm. cephalad of 

 its separation from the R. ophthalmicus separates into the 

 Rr. maxillaris and mandibularis. The last ganglion cells dis- 

 appear .7 mm. cephalad of the first, thus making .7 mm. the 

 length of the Gasserian ganglion. 



Slightly cephalad of the subdivision into the Rr. maxillaris 

 and mandibularis the motor branches of the Trigeminus to 

 Mm. pterygoideus and temporalis are given off. These branches 

 all arise together from the same point on the ventral side of 

 the R. mandibtilaris . Some distance cephalad of this, and in 

 about the same transverse plane as the posterior nares, the R. 

 mandibularis gives off branches innervating the M. masseter. 

 Still further along it bends mesad and gives off the musculo- 

 cutaneous branch to the M. submaxillaris (mylohyoideus ante- 

 rior) and the skin beneath it. As it finally breaks up it 

 innervates the Mm. submentalis and mandibulo-labialis of 

 Schulze (54). 



The cutaneous branches which compose the bulk of the R. 

 mandibularis need not be described here. The general manner 

 of termination of cutaneous nerves will be touched upon 

 below. The character of the fibres of the R. mandibularis, as 

 well as of the fibres of the R. maxillaris, is similar to that of 

 the fibres of the R. ophthalmicus, and what has been said of 

 the latter applies to them also. 



Besides its motor and cutaneous branches, the R. mandi- 

 bularis innervates a part of the epithelium of the mouth. At 

 200 a twig is detached which proceeds mesad to the mouth at 



