PHYSIOLOGY OF GUSTATION 161 



barbels. When a piece of meat is brought into contact 

 with the barbel of one of these fishes, the animal will 

 immediately seize and swallow the morsel. The same is 

 true when the meat is brought in contact with the side of 

 the fish. This quick seizure and swallowing of the food 

 has been called by Herrick the gustatory response. If 

 a barbel or the flank of Amiurus is touched with a pledget 

 of cotton instead of the meat, the fish will turn toward 

 the object, but, as a rule, will not snap at it. This Herrick 

 has designated the tactile response. If, now, the 

 cotton is soaked with meat juice and brought to the side 

 of the fish, the quick gustatory response follows. The 

 same form of response is made to meat juice discharged 

 from a pipette on the side of the fish. From this and 

 other tests Herrick concluded that the gustatory response 

 in Amiurus could be called forth by purely gustatory 

 stimuli unaccompanied by touch and that for this fish 

 taste is accompanied by a local sign as touch is. That 

 these responses are really gustatory is shown by the fact 

 that when the branch of the seventh nerve that innervates 

 the taste-buds on the flank of Amiurus is cut, the re- 

 sponses no longer occur (Parker, 1912). 



Conditions similar to those in Amiurus were recorded 

 by Herrick in a number of gadoid fishes and it is thus 

 clear that taste is a general integumentary function in 

 many of these animals. To what extent the taste-buds of 

 the fish skin are differentiated for the several senses of 

 sour, saline, bitter, and sweet cannot be stated. It is 

 remarkable, however, that in almost all the fishes tested 

 no response to sugar has been found not only on the sur- 

 face of the body but also in the mouth (Parker, 1912). 

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