426 Journal of Comparative Neurology and Psychology. 



Fig. 5. Section through the commissural nucleus of Cajal, showing the visceral division of the com- 

 missura infima above and a vestige of the somatic division below. At this level the median and lateral 

 funicular nuclei are extensive, but the spinal V nucleus has shrunken to a mere vestige, the substantia 

 gelatinosa of Rolando. Extensive secondary tracts run from the latter nucleus and from both the lateral 

 and the median funicular nuclei for the formatio reticularis of the same side and, by way of the ventral 

 commissure, for the formatio reticularis and lemniscus of the other side. The ascending portion of the 

 dorso-lateral fasciculus is reduced in size, having largely terminated in the formatio reticularis and 

 funicular nuclei farther caudad. The tract designated x in Fig. 4 is present in the ventral part of the 

 spinal V complex. The dorsal part of the dorso-lateral fasciculus is composed almost exclusively of 

 descending secondary gustatory tracts from the facial lobe, which likewise terminate in both the median 

 and lateral funicular nuclei, chiefly the latter. X 35. 



com.inf., commissura infima, visceral part above and somatic part below; com.nuc.v., visceral com- 

 missural nucleus (nucleus of Cajal); cut. X., general cutaneous root of the vagus nerve; f.d.l., fasciculus 

 dorso-lateralis; /./.,fasciculus lateralis; /./.w. , fasciculus longitudinalis medialis; /.r., formatio reticularis; 

 f.v., fasciculus ventralis; n.amb., nucleus ambiguus; rt.jn.l., lateral funicular nucleus; n.fn.m., median 

 funicular nucleus; n.int.X., caudal end of nucleus intermedins vagi; r.d.X., descending sensory root of 

 the vagus; s.gel., substantia gelatinosa Rolandi; sp.V.tr., spinal V tract; tr.sp.h.tect., tractus spino- et 

 bulbo-tectalis; w., tractus bulbo-spinalis; y., secondary tracts from lateral funicular nucleus. 



