Landacre, Taste Buds of Anu-iurus. 9 



These differences cannot be explained on the basis of a larger 

 or smaller number of communis fibers in a particular ramus in 

 various types, such as the teleosts, for while no enumerations have 

 been made, it is altogether probable that Ameiurus not only con- 

 tains more rami bearing communis fibers, but contains more com- 

 munis fibers in a given ramus than either Gadus or Menidia or 

 Pleuronectes, if we may judge from the number ot taste buds on 

 the surface in a given area. Of course, we would have to except 

 from this general rule the nerves supplying the palatal organs in 

 the cyprinoids. Judging by the variable number of rami of the 

 V and VII nerves used by communis fibers in the teleosts, it would 

 seem that the constancy of these rami in this group is not main- 

 tained primarily by the communis system, but has to be accounted 

 for by the phylogenetically older and more constant general cuta- 

 neous system and in some cases the lateralis system of fibers. 

 In an attempt to explain how this variation came about it is im- 

 portant to keep in mind the proximity of the ganglia of the com- 

 munis, general cutaneous, and lateralis components in the tri- 

 gemino-facial complex, which seems to furnish a clue to the way 

 in which communis fibers have used them in some types and have 

 not used them in others. In Ameiurus we have an extreme case 

 of this usurpation where ten out of twelve rami carry communis 

 fibers. Since the brain center is constant in position and mor- 

 phologically single in all these types, and since fibers grow both 

 peripherally and centrally from the ganglion cells, it would seem 

 that our attention should be given largely to the ganglion as a 

 source of variation. The question of the relation of the fibers 

 to the taste buds will be taken up under the general survey of the 

 oral and cutaneous groups. 



2. MATERIAL AND METHOD. 



In order to determine the place of first appearance and the rate 

 and manner of distribution of the taste buds, a number of series 

 of young Ameiurus melas were taken and the total number of 

 buds enumerated and their locations tabulated. 



The most complete series and the one from which most of the 

 tabulations were made was found in a nest at Sandusky, Ohio, 

 on July I, 1905, at 3.30 p. m. Both parents were on the nest and 

 the eggs were apparently just being deposited and fertilized. 

 The nest was conveniently located near the edge of a pond so 



