8o Bulletin of Laboratories of Denison University ['^'"'- ^ii^ 



has other connections (with the substantia reticularis of the 

 oblongata, optic thalamus, etc.) which I have not yet fully work- 

 ed out. Its homologies are discussed briefly beyond. An- 

 other part of the "Uebergangsganglion" which serves as a 

 gustatory reflex center is the nucleus already designated as sub- 

 stantia reticularis grisea trigemini. There remain several consid- 

 erable collections of cells in the "Uebergangsganglion" which 

 may have gustatory functions, but their discussion would 

 involve a more extensive analysis of the mesencephalon than 

 we can here attempt. 



A typical illustration of the chief tertiary gustatory neu- 

 rones in the cortex of the secondary gustatory center of the 

 carp is seen in Fig. 25. The dendrite plunges into the axial 

 portion of the nucleus ("Rindenknoton," Mayser) and there 

 spreads out widely among the termini of the secondary gusta- 

 tory fibers (cf. Figs 22, 23). The neurite passes downward to 

 enter at once the tertiary gustatory tract for the inferior lobe of 

 the same side, where it takes up a dense medullary sheath and 

 so is rarely completely impregnated in Golgi preparations. 

 These medullated fibers mingle immediately with similar ones 

 of the cerebellar tracts (lobo-cerebellaris and others) which en- 

 capsule the secondary nucleus and which likewise pass into the 

 inferior lobe, so that I have found it impossible in Weigert 

 sections to effect the separation of the two classes of fibers 

 except at the origin of the tertiary gustatory tract from its nu- 

 cleus. I have, fortunately, secured a sufficient number of com- 

 plete Golgi impregnations to show the origin of the tract with- 

 out uncertainty. Its entire extent save the terminal arboriza- 

 tion is shown in Fig. 23. 



The combined tract passes ventrad and somewhat cephalad 

 to enter the caudal border of the inferior lobe and spread 

 throughout the whole of the lateral lobule of this organ. Wheth- 

 er any of these fibers reach the median lobule my preparations 

 do not definitely determine, but apparently not. (The terms 

 lateral and median lobules are used in the sense defined by 

 David ('92). The lateral lobules are the h}'poaria and the 

 median lobules the mammillary bodies of C. L. Herrick ('92) ). 



