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This bundle (fasciculus solitarius in man) with its accompanying gray 

 matter might best be known in all vertebrates simply as the visceral 

 sensory column. The terms lobus vagi, lobus facialis and lobus tri- 

 gemiui, which have caused much confusion in the past should be drop- 

 ped. If it is desired to refer to the projection of the visceral sensory 

 column into the ventricle which is so prominent a feature of the brains 

 of fishes, the term lobus visceralis could be used and its two portions 

 could be spoken of as the pars vagalis and pars facialis. There has 

 never been any reason for the existence of the term lobus trigemini. 

 The secondary tract from this column is related to all three nerves 

 mentioned, and in teleosts in greatest part to the facialis. It is the 

 secondary visceral sensory tract and should be so named. It is also 

 gustatory in its functions as well as general visceral. It extends into 

 the cord in fishes and is undoubtedly homologous with the direct cere- 

 bellar tract from Clarke's column in mammals. 



The secondary visceral nucleus in which the tract ends lies be- 

 neath the junction of the acusticum, cerebellum and tectum opticum 

 in fishes. It is morphologically ventral to these structures and in 

 teleosts and ganoids lies farther ventrally than in selachians, amphibia 

 and mammals. In teleosts and ganoids the nuclei of the two sides 

 are connected by a commissure through the valvula cerebelli. This 

 commissure the writer has elsewhere (12) called the inferior cerebellar 

 commissure. As Edinger has shown, his decussatio veli lies imme- 

 diately in front of the decussation of the trochlearis. I can not 

 wholly confirm his statement that the arms of the decussatio veli run 

 caudally over the outer surface of the "ganghon isthmi" and continue 

 into the oblongata. Most of the fibers of the decussatio veli are inter- 

 rupted in the "ganglion isthmi". They intermingle with the fibers of 

 . the tract which Edinger describes as continuing caudally to be lost 

 in the trigeminus root. The tract is not lost there but goes on cau- 

 dally beneath the spinal Vth tract and is the secondary visceral tract 

 above mentioned. It partially enwraps the secondary visceral nucleus 

 (the "ganglion isthmi") as if that nucleus were lying in the bowl of 

 a spoon. The relations are the same as in Acipenser. It is true that 

 some of the fibers continue into the decussatio veli but the greater 

 part of that decussation is formed of fibers arising in the nucleus, as 

 is the case with the inferior cerebellar commissure in Acipenser. From 

 the nucleus arises also a large tract which as Edinger has described 

 goes to the inferior lobes of the thalamencephon. A part of the tract 

 seems to end in the caudal part of the inferior lobes and not to go 

 to the postoptic decussation. 



