412 "Journal of Comparative Neurology and Psychology. 



tains the visceral portion of the commissure infima, consisting of 

 sparse medullated fibers and numerous unmedullated tracts. The 

 narrow end of each nucleus is directed laterally and receives the 

 most caudal (descending) sensory vagus root. This root is un- 

 usually large and spreads throughout the substance of the lobe. 

 Numerous fascicles of root fibers pierce the lobe to cross in the 

 commissura infima above the ventricle. These lobes receive, as 

 in Ameiurus, large numbers of feebly medullated diffuse tracts 

 from the layer of secondary tracts of the vagal lobes. These end 

 partly uncrossed and partly crossed. 



These visceral nuclei pass forward into the nucleus intermedius 

 vagi, as just stated, and ventrally they are bounded by the somatic 

 sensory centers and their commissure. The dorsal part of the 

 somatic commissura infima is blended with the ventral part of 

 the visceral commissure. The visceral commissure is diffuse and 

 chiefly unmedullated. The somatic commissure contains numer- 

 ous separate fascicles of heavily medullated fibers, some of which 

 come from the dorso-lateral fasciculi, and also more lightly 

 medullated fibers which connect the adjacent funicular nuclei and 

 formatio reticularis. 



The somatic sensory centers are nearly as large as in Ameiurus, 

 but do not show as much differentiation. The lateral funicular 

 nucleus is distinct; the median nucleus and nucleus of the spinal 

 V tract are indistrnguishably fused. They extend far forward 

 under the visceral nuclei, the latter having been crowded back- 

 ward by the enlarged vagal lobes. Both funicular nuclei receive 

 descending secondary gustatory fibers from the facial lobe. Most 

 of these fibers end in the median nucleus, while the lateral nucleus 

 receives a much larger proportion of fibers from the dorso-lateral 

 fasciculus. Both nuclei are, therefore, as in Ameiurus, correlation 

 centers for tactile and gustatory sensation from the outer skin 

 (Herrick 1906). Their secondary connections are as in Ameiurus 

 and in addition there is a large tract of small medullated fibers from 

 the median nucleus and the formatio reticularis ventrally of it, which 

 crosses at once in the ventral part of the somatic commissura infima 

 and then passes headward along the lateral border of the ventricle 

 to end in the nucleus ambiguus. This is evidently a direct path 

 from the tactile-gustatory correlation center to the nucleus of the 

 gill muscles, and may be termed the tractus funiculo-ambiguus 

 (fig- 4^- 



