Kingsbury, Brain of Nectiinis. 



179 



VAGUS NERVE. 



As compared with the origin in Cryptobranchus as set forth 

 by Osborn, the following differences may be noted : his solitary 

 bundle enters two roots in CryptobrancJuts, but one in Necturus. 

 The fasciathis coiwminis enters two roots, one in Necimus. 

 Further, no ascending sensory root m addition to the fasciculus 

 commu7iis was found by him ; in Necturus it enters three roots 

 though in two of them the contingent was small. 



Strong's results on the tadpole show slight differences, the 

 most important of which is the changed relation of the fascicu- 

 lus communis and (his) ascending V components, the first being 

 ventral in the tadpole, dorsal in Necturus. There seem to be 

 fewer roots, three only being recognized by him, the first draw- 

 ing its fibers from \\\q. fasciculus communis, ascending tract (his 

 ascending V) and a motor nidus ; the second, fasciculus communis 

 and a motor nidus; the third, ascending lateral tract (solitary bun- 

 dle of Osborn). The differences in the relation o{ the fasciculus 

 communis should be noted. As to whether the ascending fibers 

 of the tenth nerve can be said to be derived from the ascending 

 V is merely a matter of definition ; they are, indeed, closely 

 associated with that tract. 



Glossopharyngcus. — This is closely related to the vagus, and 

 possibly would have been better discussed with it. What are 

 treated here under this name include the ninth nerve proper, 

 and, from the researches of Strong, the representative of the 

 " Ramus lateralis vagi," or " Nervus lateralis " of other Ichthy- 

 opsida. 



The nerve is distinct from the vagus almost up to its gang- 



