Herrick, Brain of the Codfish. 73 



rus in a separate lobe in front, the lobus facialis ? Why should not 

 the cutaneous gustatory nerves of Ameiurus end likewise in the 

 vagal region ? That there is no mechanical impediment to the 

 necessary enlargement of the vagal lobe is evident from the fact 

 that in the carp the vagal lobe suffers much greater enlargement to 

 provide a terminal nucleus for an increased number of taste buds 

 within the mouth. 



In Ameiurus many, though by no means all, of the cutaneous 

 taste buds are in the head. Ihese areas of skin receive their 

 tactile innervation from the trigeminus nerve. Now, I have found 

 in this fish two centers of correlation between the nerves of touch 

 and taste from the skin of the head. One is the funicular nuclei, 

 already referred to. The other is in the facial lobe, in whose 

 deeper layers trigeminus root fibers have been found to end. The 

 demand for a correlation center in front of the vagal lobe is proba- 

 bly the motive which in Ameiurus has drawn the facialis gustatory 

 center cephalad of the vagal lobe, thus providing also an imme- 

 diate path from end organs of both touch and taste to the motor 

 centers of the barblets and jaws. In the gadoids, on the other 

 hand, some of the most important areas of distribution of cutaneous 

 taste buds are on the fins, which are freely moved about in the 

 exploration of food objects. These receive their tactile innerva- 

 tion from spinal nerves which enter behind the vagal lobes and, 

 therefore, the motive for a forward movement of the somatic gusta- 

 tory center to correlate with the corresponding tactile nerves does 

 not exist to so high a degree, or possibly has been counteracted 

 by stronger spinal tactile impulses associated with gustatory 

 stimuli on the fins. 



But this explanation still leaves unaccounted for the short-circuit- 

 ing of the somatic gustatory path in the cod by which it passes 

 under the tactile centers without connection with them and 

 reaches the motor centers directly. The peculiar feeding habits 

 of the cod may explain this arrangement (Herrick '04). 



The body taste buds of Gadus and its allies are most abundant 

 on the filiform pelvic fins, and these are the organs most used in 

 the detection of food, serving a purpose closely similar to that of 

 the barblets of Ameiurus. In Ameiurus the somatic reaction 

 consequent upon contact of a barblet with food is a lateral turning 

 of the whole body by a single movement to reach the food object. 



