Art. VI.] Herrick, Taste in Fishes. 89 



surface ; in both cases the peripheral communis nerves corre- 

 spond to the general teleostean type, though with a remarka- 

 ble modification of the recurrent branch of the facialis in the 

 case of the cyprinoids ; and finally the communis centers in the 

 medulla oblongata differ from those of all other teleosts in that 

 there is developed a facial lobe as well as a vagal lobe in the 

 primary central gustatory center. The facial lobe (the so-called 

 lobus trigemini of siluroids and the "tuberculum impar" of 

 cyprinoids) in both cases receives by way of the communis root 

 of the facialis the nerve fibers from all of the terminal buds of 

 the outer skin, while the vagal lobe is reserved for those from 

 the mouth and viscera. This emphasizes from a new point of 

 view the close relationship between these two groups of fishes, 

 as recognized by the systematists generally. 



Though the Ostariophysi may have had a different origin 

 from that of the other teleostean orders, yet the resemblances in 

 general plan of the terminal bud system of sense organs in this 

 group and in the other orders make it improbable that this sys- 

 tem has arisen independently and followed a parallel develop- 

 ment in the two groups of fishes. Its phylogenetic origin 

 must therefore be sought among the ganoids, and until 

 we have more exact information concerning the nerve compo- 

 nents and sense organs of these fishes further speculation in 

 this direction is idle. 



This study has been directed primarily toward the solution 

 of a simple physiological problem ; but in a purely incidental 

 way some points of interest to comparative psychology have 

 come up. We have seen that in the cat fish, hake and tom 

 cod the reflex of seizing the food is normally set off by a com- 

 bined stimulus of tactile and gustatory end-organs. At first 

 the fish may react similarly to a pure tactile stimulus and the 

 tactile plus the gustatory. After a brief training, however, he 

 acquires the ability to discriminate between the former, which is 

 never followed by satisfaction, and the latter, which is followed 

 by the pleasure of feeding. Clearly the fish learns by experi- 

 ence. We find also some differences between the different spe- 

 cies of fishes in this respect, depending on the relative impor- 



