68 Bulletin of Laboratories of Denison University. [Voi.xiii 



in diffuse formation to reach the region of the nucleus funicuh 

 and commissura infima Halleri (Figs. 19, i i). The indica- 

 tions are that it springs mainly from the smaller secondary 

 neurones of the lobe (cf. Fig. iij, though I have no conclusive 

 evidence that the chief secondary cells do not also participate in 

 its formation. 



In the region of the funicular nuclei the substantia reticul- 

 aris grisea, related above with the vagal lobe, enlarges. This I 

 term the infeiior secondary gustatory micleus (nucleus gustus se- 

 cundus inferior). It receives the diffuse tracts from the vagal 

 lobe just described, and also the greater part of the descending 

 secondary facialis tract. A portion of the latter tract, however, 

 continues into the spinal cord caudad of the funicular nuclei in 

 the ventro-lateral tracts. 



This inferior gustatory nucleus is intimately related with 

 the termini of the spinal V tract, funicular nuclei, commissura 

 infima Halleri and commissural nucleus of Cajal. It is clearly 

 a coordination center between gustatory and tactile sensory im- 

 pressions. In fishes with feebly developed gustatory system it is 

 of insignificant size. Its great development in the cyprinoids and, 

 as we shall see, in the siluroids is correlated with the known feed- 

 ing habits of these fishes. It has been shown (Judson Herrick, 

 '04) that fishes with taste buds in the outer skin taste with these 

 organs and habitually localize the food stimulus partly by the 

 sense of taste and partly by tactile stimulation of the same 

 cutaneous areas. It may safely be inferred that the descending 

 secondary gustatory connections of these fishes are especially 

 adapted to serve this correlation of the senses of taste and 

 touch as employed in localizing peripheral stimuli in the search 

 for food and to call forth the bodily movements necessary to 

 seize the food when its position has been determined. 



The detailed description of these connections involves the 

 discussion also of the secondary connections of the general cu- 

 taneous (somatic sensory) system of neurones and must be re- 

 served for a later contribution. 



(2) Ascending Secondary Gustatory Tract. 



This tract, which takes the greater part of the fibers aris- 



