68 Joia-nal of Comparative Neurology and Psychology. 



The central gustatory paths have been investigated in cyprinoids 

 and siluroids (Herrick '05). In view of the demonstration, in 

 the works cited in the preceding paragraphs, of the essential simi- 

 larity in the structure, innervation and function of the cutaneous 

 taste buds of cyprinoids, siluroids and gadoids, we should expect 

 their central connections in the group last mentioned to resemble 

 those described for the two former groups. But the facts seem 

 to be quite the contrary, and the primary purpose of this inquiry 

 was to determine the extent and if possible the functional signifi- 

 cance of these differences. This naturally led to a study of the 

 tactile centers also in Gadus, for the underlying problem in both 

 this and my previous study ('06) is the central relations of those 

 tactile and gustatory nerves which innervate the same areas of 

 skin and have independent local signs but common pathways of 

 motor discharge in the reaction. 



THE CENTRAL GUSTATORY PATHS OF AMEIURUS AND GADUS. 



In siluroids and cyprinoids practically all the nerves supplying 

 taste buds in the outer skin, lips and palate terminate in a single 

 huge nucleus which forms a dorsal protuberance on the medulla 

 oblongata, the facial lobe, while taste buds of the pharynx and gill 

 region are innervated from the vagal lobe farther back in the 

 oblongata. 



In the gadoid fishes a facial lobe has been described and figured 

 by several previous authors; but my examination of the brain of 

 the cod shows that the facial lobe does not exist in the form 

 described by these authors. Nevertheless I find the peripheral 

 distribution of the gustatory root of the facial nerve of Gadus is 

 practically the same as in Ameiurus. What, then, are the central 

 connections of the cutaneous taste buds in Gadus .? 



Taste buds are scattered over the whole body of Ameiurus but 

 most abundantly on the barblets, and experiment shows that these 

 are very sensitive to both tactile and gustatory stimulation. They 

 are constantly used for the exploration of the bottom and the 

 maxillary barblets are actively waved about whenever a savor dif- 

 fuses through the water. In the gadoids, particularly the tom-cod 

 and the hake, the free filiform rays of the pelvic fin function in a 

 similar fashion and are likewise richly supplied with end-organs 

 of both taste and touch. 



