Herrick, Gustatory Paths in Fishes. 383 



rowly defined. A summary of the nomenclature here employed 

 for the gustatory system of these fishes is given in tabular form 

 in Section V, to which frequent reference should be made. 



/. Primary Gustatory Centers. 



The general topography for the vagal and facial lobes of 

 cyprinoid fishes has often been described, and the reader is re- 

 ferred for the details to the classic paper of Mayser ('82). and 

 also to the figures of Bela Haller ('96), whose descriptions, 

 however, I do not in all things confirm. I have found little in 

 the extensive work of this author ('98) on the brains of Salmo 

 and Scyllium which sheds further light on the secondary con- 

 nections of the vagal lobe. However, I do not profess to have 

 mastered the contents of this unsystematic and obscure paper, 

 though I have dilligently studied it. Nor is there anything of 

 importance from our present point of view in the recent disser- 

 tation on the vagal lobes of cyprinoids by Groth ('00), whose 

 purpose was merely to test the accuracy of some of Haller's 

 observations on nerve anastomoses in these fishes. 



The vagal lobe of the cyprinoids, as compared with that of 

 the siluroids and the teleosts generally, represents an en- 

 largement of both the sensory and the motor centers of 

 the vagus and glossopharyngeus. This enlargement is corre- 

 lated with the development of the curious palatal organ in the 

 mouth of these fishes, the sensory fibers being derived from the 

 taste buds which cover the surface of this organ and the motor 

 fibers going out chiefly to the small muscles which permeate its 

 interior. The " motor layer " of the vagal lobe, from which 

 these motor fibers are derived is a dorsal extension of the nu- 

 cleus ambiguus. The latter nucleus has the typical position 

 and relations, supplying the branchial musculature, and is not 

 commonly regarded as a part of the vagal lobe. 



We shall describe, so far as the material at command per- 

 mits, the conduction pathways in the vagal lobe of the larger 

 cyprinoids on the basis of sections of adult and young brains 

 cut in various planes and stained by Delafield's haematoxylin 

 and the methods of Weigert-Pal and Golgi. The illustrations 



