602 



exit. It separates and passes forwards, about half of its fibres soon 

 passing downwards to reënforce the ventral VII. (VII. a) as described 

 above. The remaining fibres proceed along the dorsal side of the Gas- 

 serian ganglion and divide, one part receiving a filament of the Sym- 

 pathetic and proceeding outwards to bend forwards under the eye while 

 the other part proceeds upwards, pierces the cranium by a separate 

 foramen and runs directly forward along the top of the head. Both of 

 these parts, a short distance from the Gasserian ganglion, fuse for a 

 small part of their course with branches from the Trigeminus. They 

 are both cutaneous and seem to follow the lines of the lateral sense 

 organs seen in the Tadpole to which I believe they belong. The fibres 

 of the dorsal VII. are coarse and very uniform in size. In Desmognathus 

 and Spelerpes, the above description also holds good essentially except 

 that the Fasciculus communis is given off above the Auditory and 

 therefore immediately below the dorsal VII., which agrees mth 

 Osborn's account of Cryptohranchus. 



The dorsal VII. is largest in Urodela, is reduced in Tadpoles of 

 Aiiura and is entirely wanting in the full grown Frog and Toad. This 

 disappearance accounts for the apparent discrepancy between Osborn's 

 account of the Facial as mainly dorsal to the Auditory in Urodela and 

 the usual account according to which it is ventral to the Auditory in 

 Aiiura and higher forms. 



In some Urodele forms examined, the nerve VII. a + V2 VII. h was 

 seen to have two ganglia, one immediately below the Auditory ganglion 

 and probably belonging to the Palatine (Fasciculus communis) 

 portion and the other further outAvards on the Hyomandibular. In 

 Anurous forms examined, including Tadpoles, no ganglion cells seem 

 to occur on the VII. until its connection with the Gasserian ganglion. 

 This being the case, it is evident that the Gasserian ganglion in Anura 

 is very complex, consisting not only of the ganglia of the Maxillo- 

 mandibularis and the Ophthalmicus trigemini but also of the Palatine 

 and of the branches of the dorsal VII., if the latter have ganglia, as 

 long as they persist. 



The anterior root of the Glossopharyngeal 

 and Vagus group. 



This arises usually some distance cephalad of the other roots and 

 also much more dorsally . Its fibres can be tolerably well traced through 

 the ganglia of the IX. + X. and all its branches appear to have a cuta- 

 neous distribution. It is to be regarded as the Lateral nerve and in 

 respect to the origin of its fibres, their character and distribution, it 

 agrees with the dorsal VII. 



