82 Bulletm of Laboratones of Denison University. [Voi. xiii 



The course of the tractus lobo-bulbaris as it leaves the in- 

 ferior lobe is clearly shown in some of my Golgi preparations. 

 In Weigert sections this tract is so confused at its origin with 

 the fibers of the tractus lobo-cerebellaris and tertiary gustatory 

 path that it cannot be clearly distinguished at first. Its fibers 

 throughout their course are very fine and feebly medullated. 

 The tract passes up from the inferior lobe and arches around 

 the ansulate commissure to turn caudad along the inner border 

 of the lemniscus. Upon reaching the level of the secondary 

 gustatory nucleus it turns laterad over the dorsal surface of the 

 lemniscus (Fig. 24) and takes up a position ventrally of the 

 secondary gustatory nucleus (Fig. 20, tr.l.b.). Farther back it 

 becomes partially enveloped by the ascending fibers of the sec- 

 ondary gustatory tract. The latter tract in cross section is cres- 

 cent-shaped and the concavity of the crescent, which faces in- 

 ward, is occupied by the descending fibers of the tractus lobo- 

 bulbaris. This tract is thus placed along the dorso-lateral 

 border of the substantia reticularis, which, as we have seen, is 

 the chief avenue of communication with the motor nuclei of the 

 oblongata. The tractus lobo-bulbaris diminishes caudad, break- 

 ing up in the substantia reticularis and so puts the gustatory 

 center in the inferior lobe into relation with the peripheral mus- 

 culature. It doubtless extends into the spinal cord, but it is 

 impossible to distinguish its fibers from the others in the sub- 

 stantia reticularis alba farther back than the vagal lobes. 



Section IV. The Central Gustatory System of Siluroid 



Fishes. 



As we have seen above, the anatomy and physiology of 

 the peripheral gustatory system of the cat fishes, or horned 

 pouts, is now well known. The cutaneous portion of the sys- 

 tem is here hypertrophied, while the buccal portion is about as 

 in other fishes. This is the explanation of the fact that the cat 

 fishes possess enlarged facial lobes, while the vagal lobes are of 

 the typical teleosteanform. We shall now proceed to a descrip- 

 tion of the internal anatomy and secondary connections of these 

 structures in Ameiurus and closely related species. The mater- 



