428 'Journal of Comparative Neurology and Psychology. 



Fig. 6. Section through the caudal part of the vagal lobes of Ameiurus, including the cephalic tip 

 of the commissural nucleus of Cajal at the point where it fuses with the nucleus intermedius vagi. 

 Both funicular nuclei have disappeared. The area marked substantia gelatinosa Rolandi includes the 

 indistinguishable vestiges of the spinal V nucleus and the median funicular nucleus. Above the spinal V 

 tract a vestige of the lateral funicular nucleus is seen from which tracts of heavily medullated fibers run 

 downward as internal arcuate fibers for the ventral commissure and lemniscus of the opposite side. 

 These tracts are still larger in the sections immediately caudad of the one figured. The fasciculus 

 dorso-lateralis at this level is composed chiefly of descending secondary gustatory tracts from the facial 

 lobe. Some strands of these fibers (marked v.") pass up internal to the substantia gelatinosa to reach the 

 nucleus intermedius of the vagal lobe where it passes over into the commissural nucleus of Cajal. The 

 latter nucleus is broadly connected with the formatio reticularis by both medullated and unmedullated 

 tracts. 



asc.sec.X., ascending secondary gustatory tracts from the vagal lobe; com.nuc.v., extreme cephalic 

 end of the visceral commissural nucleus (nucleus of Cajal); cut.X., general cutaneous root of the 

 vagus; /.if./., fasciculus dorso-lateralis;/./., fasciculus lateralis ;/./.«., fasciculus longitudinalis medialis; 

 /.r., formatio reticularis; j.v., funiculus ventralis; ^.a/wt. nucleus ambiguus; «./«./., extreme cephalic 

 end of lateral funicular nucleus; n.int.X., nucleus intermedius vagi; r.X., chief sensory root of the 

 vagus; s.gel., substantia gelatinosa Rolandi, with which is fused the extreme cephalic end of the median 

 funicular nucleus; sp.F.tr, spinal V tract; tr.h.tect., tractus bulbo-tectalis from lateral and median funi- 

 cular nuclei; tr.sp.h.tect., tractus spino- et bulbo-tectalis; v., strands of the descending secondary 

 gustatory tract from the facial lobe for the cephalic end of the commissural nucleus of Cajal. 



