Herrick, Gustatory Paths in Fishes. 45 1 



pond topographically with the dorsal horn of the spinal cord, 

 but with the region of Clarke's column. In the present state 

 of our knowledge, no precise comparisons are possible between 

 the gustatory secondary connections and those of the visceral 

 centers of the spinal cord. And in the brain, where our knowl- 

 edge of the connections of the nerves is more exact, there is no 

 close resemblance between the secondary gustatory and any 

 other secondary sensory system. 



The acustico-lateral and tactile systems have been shown 

 to be intimately related and their secondary tracts in fishes are, 

 in a general way at least, known, crossing immediately in the 

 ventral commissure and ascending in the lemniscus (fasciculus 

 lateralis) to the opposite mesencephalon. Clearly there is no 

 close resemblance here with the gustatory connections and it is 

 difficult to conceive how either form could have been derived 

 from the other. 



Given a primitive elongated gustatory center in the oblon- 

 gata, like that associated with the fasciculus communis of the 

 amphibia, and the development of all types of primary gusta- 

 tory centers known among fishes can be easily understood by 

 simple hypertrophy of different parts of the system. We have 

 seen in the preceding descriptions that the secondary gustatory 

 connections are in almost all cases through the substantia retic- 

 ularis grisea or derivatives from it. This applies both to the 

 short connections and to those by way of the superior and in- 

 ferior secondary nuclei. In the two latter cases the connection 

 is partly on the same side and partly on the opposite side 

 through a commissure. 



The superior secondary nucleus is clearly adapted to serve 

 the higher gustatory reflexes, and various coordinations, chiefly 

 with smell and sight. The connection with thevalvula cerebelli 

 and cerebellum is very perplexing. There is a suggestion in 

 certain comparative anatomical facts that the valvula cerebelli 

 of teleosts (or at least its lateral lobes which are broadly conflu- 

 ent with the nucleus lateralis) has been differentiated in connec- 

 tion with the secondary gustatory nucleus. The valvula is 

 largest in those teleosts which have the most highly developed 



