Art. VI] Herrick, Tasti in Fishes. 8/ 



which lack these organs in the skin have the sense of taste con- 

 fined to the mouth. The dehcacy of the sense of taste in the 

 skin is directly proportional to the number of terminal buds in 

 the areas in question. 



Numerous unrelated types of bony fishes from the siluroids 

 to the gadoids which possess terminal buds have developed 

 specially modified organs to carry the buds and increase their 

 efificiency. These organs may take the form of barblets or of 

 free filiform fin rays. The free rays of the pelvic and dorsal 

 fins of gadoid fishes are thus explained, and indeed this is possi- 

 bly the motive for the migration into the jugular position of 

 the pelvic fins of the gadoids. 



In all cases where terminal buds are found on barblets or 

 filiform fin rays gustatory nerves belonging to the communis 

 system are distributed to them. These barblets and free fin 

 rays likewise receive a very rich innervation of tactile or gen- 

 eral cutaneous nerves, so that they merit their popular designa- 

 tion, "feelers." Both sets of end organs undoubtedly 

 cooperate in the discrimination of food and the animal 

 has the power of very accurate localization of the stimu- 

 lus. Whether the gustatory stimulus alone can be localized 

 apart from its tactile accompaniment cannot at present be 

 stated. A purely tactile stimulus with no gustatory element 

 can be localized precisely and I have as yet no conclusive evi- 

 dence that a pure gustatory stimulus even when strong, can be 

 located by the fish. It is certain that feeble and widely dif- 

 fused gustatory stimuli cannot be accurately located by the 

 fishes which I have experimented with either by the terminal 

 buds or by any other organs. 



The fishes in which the cutaneous terminal buds are most 

 highly developed are in general bottom feeders of rather slug- 

 gish habit and in some cases they are nocturnal feeders. The 

 high development of this sense is compensated for in some 

 fishes by the reduction of others. The visual power of the 

 fishes is especially apt to suffer degradation. This degradation 

 may be organic, a positive degeneration of the visual apparatus, 

 as in Ameiums, or it may be merely functional. In the latter 



