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



and are of the same type as in cyprinoids. Their neurites, 

 mingUng with the tractus lobo-cerebellaris, pass down to end in 

 the inferior lobe of the same side, essentially as already describ- 

 ed for the carp. The ventral portion of this tract and its ter- 

 minal arborizations are seen in Fig. i"] . 



The return path in the oblongata by way of the tractus 

 lobo-bulbaris is also essentially as described for the carp. 



Section V. Summary and General Conclusions. 



In this section a brief summary of the facts as described in 

 the preceding pages is followed by a discussion of some of the 

 morphological considerations growing out of them. 



The teleostean fishes generally possess taste buds freely 

 scattered over the mucous surfaces of the mouth, gills and lips. 

 The group of Ostariophysi is characterized by a very great de- 

 velopment of this system of sense organs — in the siluroids in 

 the outer skin and barblets and in the cyprinoids both in the 

 outer skin and in still greater degree in the palatal organ within 

 the mouth. 



It has previously been shown experimentally that these 

 fishes do in reality taste with their cutaneous taste buds, which 

 are often called terminal buds and which have no relationship 

 whatever with any variety of lateral line organs. Furthermore, 

 while pure cutaneous gustatory stimuli can be localized by the 

 fish, ordinarily both gustatory and tactile stimuli cooperate in 

 the discrimination and localization of food objects. 



The distribution and innervation of the organs of taste 

 have been accurately determined for the siluroid fish, Ameiurus, 

 all of them being innervated by the communis system of per- 

 ipheral nerves. The nerves from the buds in the outer skin 

 enter the brain exclusively by the facialis root ; those from with- 

 in the mouth by the facialis, glossopharyngeus and vagus roots, 

 chiefly the latter. A special tuberosity of the brain, the lobus 

 vagi, serves in fishes generally as the primary cerebral center 

 for all gustatory nerves. This is greatly enlarged in some cyp- 

 rinoids to provide for the taste buds in the palatal organ, and 

 in both cyprinoids and siluroids there is another tuberosity de- 



