42 Bulletin of Laboratories^, of Denison Uniefvsity. [Voi. xiii 



facialis (Judson Herkick, 'oi) and since the palatal and other 

 branches of the communis VII root which supply taste buds 

 within the mouth are not enlarged, as compared with other 

 fishes, it is clear that the enormous communis VII root and the 

 lobus facialis in which it terminates are related mainly to 

 cutaneous taste buds in these fishes. 



//./.-I 



Fig. 4. Dorsal view of the brain of the yellow 

 cat fish, Leptops olivaris (Raf.), X 2. 



The olfactory bulbs are cut off ; also the mem- 

 branous roof of the fourth ventricle, exposing the 

 . facial lobes (Z. /".) and vagal lobes (Z. V.). This 

 ventricle is bounded behind by a transverse ridge 

 containing the commissura infima Halleri (c. i.) 

 and the commissural nucleus of Cajal. The tuber- 

 osity laterally of the cerebellum and facial lobe is 

 the lobus lineae lateralis (/. /. /.), which is greatly 

 enlarged and entirely conceals the superior second- 

 ary gustatory nucleus. 



Section III. The Central Gustatory System of Cvpri- 



NOiD Fishes. 



We shall now proceed with a description of the gustatory 

 pathways in a selected series of teleosts, beginning with the 

 larger cyprinoids where it attains its maximum development. 

 The results here obtained will be controlled by an equally care- 

 ful examination of the brains of siluroid fishes (particularly 

 Ameiurus), whose gustatory centers differ greatly in detail from 

 those of the carp-like forms. These minor differences will serve 

 to bring out more clearly the points of fundamental resemblance, 

 which are very striking. 



The end-station of the gustatory neurones of the first order 

 (peripheral neurones) is the nucleus of origin for the neurones 

 of the second order, giving rise to secondary gustatory tracts, 

 and these in turn to tertiary tracts. The nomenclature of these 

 tracts and centers offers almost insuperable difficulties and some 

 new terms will have to be introduced and old ones more nar- 



