Herrick, Braiti of the Codfish. 69 



In Ameiurus the facial lobe, which receives all the gustatory 

 nerves from the outer skin, gives rise to two chief secondary tracts. 

 One passes upward into the mid-brain and one downward toward 

 the spinal cord. The first of these accompanies the ascending 

 cerebral tract for taste from the vagal lobes and is feebly developed 

 or absent in the cod. It will therefore receive no further considera- 

 tion here. The descending path terminates, as shown in Fig. i, 

 in the primary tactile correlation center of the brain, the funicular 

 nuclei, and farther caudad in the spinal cord. From this corre- 

 lation center a common motor pathway runs out by way of the 

 funiculus ventralis for the innervation of all the somatic muscles 

 of the body. 



Now remembering that the body, considered as a reflex mechan- 

 ism comprises two primary systems (the somatic system lor reaction 

 of the body as a whole to external stimuli, and the visceral system 

 for correlation of the internal parts by reaction to visceral stimuli), 

 we may summarize the reflex connections of the taste buds of 

 Ameiurus as follows: The primary gustatory center is diff'eren- 

 tiated into a visceral region (vagal lobe) for taste buds lying in 

 mucous membranes and a somatic region (facial lobe) for taste 

 buds lying in the outer skin. The somatic character of this latter 

 region has been secondarily acquired. It was without question 

 phylogenetically derived from the visceral center. Both centers 

 send an ascendino- tract to a common mid-brain nucleus. Their 

 descending paths are strikingly different. The visceral center 

 (vagal lobe) makes reflex connections only with the visceral muscu- 

 lature of the jaws, gills, oesophagus, etc. The somatic center 

 (facial lobe) connects broadly with the funicular nuclei and there 

 the gustatory stimuli from the skin are correlated with tactile 

 stimuli from the same cutaneous areas and from this common 

 sensory correlation station the motor pathways go out to the soma- 

 tic muscles. There is also a direct path from the facial lobe to the 

 motor V nucleus which innervates the muscles of the barblets, 

 these being waved about when stimulated either by taste or touch. 

 The preceding description applies with but slight modification 

 also to the carp and other cyprinoid fishes. 



Now, in the cod there is no well defined facial lobe. Gustatory 

 fibers from the mouth and from the outer skin terminate in the 

 vagal lobe, a condition which was entirely inexplicable to me after 

 my demonstration physiologically that the taste buds on the fins 



