Art. VI.] Herrick, Taste in Fishes. 41 



lated to the primary central end-stations, referred to above, and 

 the chief reflex arcs directly associated therewith, we shall have 

 a picture of the system in its entirety. 



The functional system with which we are especially con- 

 cerned in the present research is that known to comparative 

 anatomy as the communis system, including (ij unspecialized 

 visceral sensory fibers ending free in the mucous surfaces of 

 various viscera without special sense organs — probably phylo- 

 genetically the more primitive elements — and (2) specialized 

 sensory fibers always ending in connection with highly differen- 

 tiated sense organs in the mouth, pharynx, lips or outer skin, 

 known as taste buds, terminal buds or end buds, and in general 

 serving the function of taste. These specialized elements are 

 probably of more recent phylogenetic origin than the first group 

 and the term gustatory system will be used to designate these 

 organs, wherever placed on the body surface, together with 

 their nervous pathways toward and within the brain. In other 

 words, the gustatory system is that portion of the communis 

 system of neurones which serves the sense of taste, as distin- 

 guished from those communis neurones which serve less highly 

 specialized visceral sensations. 



These two groups of fibers can easily be distinguished peri- 

 pherally of the brain, but centrally they have not as yet been 

 successfully analyzed. Hence in treating of the central gusta- 

 tory path we cannot be sure that we do not include the un- 

 specialized visceral system also. But since in some fishes the 

 gustatory fibers preponderate many fold over the unspecialized 

 fibers of the communis system, there is no ambiguity arising 

 from this central confusion of the two elements so far as the 

 gustatory system is concerned, since the secondary paths as 

 clearly traceable in these fishes must be made up chiefly of gus- 

 tatory fibers. 



The central gustatory path is not definitely known either 

 in man or in any other vertebrate, so far as shown by the avail- 

 able literature; I have therefore studied with some care the 

 brains of some fishes in which this system is enormously devel- 

 oped in the hope that they would throw light on this unsolved 



