90 NERVE COMPONENTS OF BONY FISHES. 



supply two very different types of sensory structures per- 

 ipherally (on the one hand the highly specialized taste 

 buds and on the other hand the simplest possible free end- 

 ings in the general visceral and mucous surfaces), the 

 attempt was made to find some morphological criterion 

 centrally for these two types of fibres. In this I was not 

 very successful, though in the ganglia we get a suggestion 

 which may be of some value. The anterior (cephalic) 

 rami of the communis system undoubtedly contribute most 

 of their fibres to taste buds and a smaller number to the 

 undifferentiated mucosa. On the other hand, as we pass 

 caudad the number of taste buds to be supplied diminishes, 

 while the proportion of undifferentiated viscero-sensory 

 fibres is greatly increased, until in the r. intestinalis and 

 the oesophageal rami the fibres all belong to this latter 

 category. Now, the ganglia of the glossopharyngeus and 

 the first branchial of the vagus are composed of very large 

 cells with medium and very small cells intermingled and 

 occasional little nests of the smallest cells crowded very 

 closely. As we go toward the caudal end of the ganglionic 

 complex, we continue to find cells of the various sizes, but 

 the smaller ones become increasingly numerous. The 

 hypothesis suggests itself that the larger cells are related 

 to the taste buds and the smaller ones to the visceral fibres. 

 A careful cytological study and comparison of the ganglion 

 cells of the several components would doubtless furnish 

 many points of morphological value. 



J. — The Cutaneous Root of the Vagus. 



Peripherally the general cutaneous branches of the 

 vagus are, as we shall see, very clearly separable from 

 all of the other fibres of the vagus complex. On the 

 other hand, the analysis proximally is attended with much 



