No. I.] THE CRANIAL NERVES OF AMPHIBIA. 135 



other — seems to occupy more the anterior portion of the 

 ventral side. Occupying the posterior portion of the ventral 

 side we have the ganglion of the fasciculus communis compo- 

 nent of the VII, from which come the R. palatinus VII and the 

 smaller branch which goes over into the R. hyomandibularis 

 VII. In the outer side of the whole ganglion, and between 

 the Gasserian ganglion proper and the ganglion of the fasci- 

 culus communis component, there are ganglion cells which 

 must be regarded as constituting the ganglion of the ventral 

 half of the dorsal VII, which subsequently forms part of the 

 R. hyomandibularis. Besides these ganglia, we have also non- 

 ganglionated bundles of fibres. There is the bundle of motor 

 fibres of the portio minor of the Trigeminus, passing through 

 the Gasserian ganglion. There is also the motor bundle of the 

 VII which passes, with the ventral half of the dorsal VII, 

 through the outer side of the ganglion. The course of the 

 Abducens has been described. It is in the lower part of the 

 inner side of the whole ganglion. Finally, there are sympa- 

 thetic twigs which join the various branches emerging from 

 this ganglionic complex (see pp. 118, 119, and 151). 



3. The Glossopharyngeiis and Vagus. 



The determination of the composition of these nerves 

 presents considerable difficulty in the tadpole, principally 

 because of the manner in which they are, as it were, pushed 

 together and out of position by the auditory capsule. Fol- 

 lowing the different roots through the ganglia accurately can 

 hardly be accomplished, yet I believe the general nature of 

 these ganglia is as described below. Some of the peripheral 

 branches also have not been traced as completely as could be 

 desired. 



Five roots can usually be distinguished composing the 

 IX + X. They are represented on the chart somewhat spread 

 out, in some particulars, for clearness. 'Y\i^ first root, i.e., that 

 one most cephalad, emerges from the medulla at 911. It 

 leaves the medulla at a more dorsal level than the other roots 

 and, as seen in the chart, as it approaches the medulla it 



