Landacre, Taste Buds of Ameiurus. 43 



In summarizing the result of the study of the oral and cuta- 

 neous groups two facts are patent, first, the spreading of buds 

 is always from anterior to posterior, and second, the spreading 

 is always by discontinuous groups. Table XIII shows the time 

 of appearance of the cutaneous, oral and pharyngeal groups. 



From Table XIII it will be seen that all the subdivisions of 

 the pharyngeal group are present long before the cerebellar and 

 occipital buds have appeared, and are present some hours before 

 the body buds appear. This is to be explained probably by the 

 homogeneous character of the pharyngeal area and by its limited 

 extent as compared with the cutaneous area. 



There are insufficient data to make a comparison of the 

 ontogenetic order in which taste buds innervated by the various 

 rami of the V and VII nerve appear in Ameiurus and other types. 

 If we arrange the nerves of Ameiurus in an order corresponding 

 to the order of appearance of the groups of taste buds it will 

 give the following arrangement: 



TABLE XIV. 



Table showing the order in which the groups of taste buds appear as related to the various rami of 

 the V and VII nerves which innervate them. 



Dorsal lip and barb, buds innervated by R. max. V 

 Ventral lip and barb, buds innervated by R. mand. V 

 Nasal buds innervated by R. oph. Sup. V 



Ant. palatine buds innervated by R. pal. VII 



Post, palatine buds innervated by R. pal. post. VII 



Post.-orbital and oper. buds innervated by R. max. acces. V.? 



R. mand. ex. VII 

 R. hyomd. (prox. twigs) 

 R. oticus 

 R. hyoideus 

 Body buds R lat. acces. 



2oi mm. Cerebell. and occip. buds innervated by Meningeal twigs and Proximal twigs 



of R. lat. acces. 



Whether we look upon the taste buds as appearing fortuit- 

 ously and later being connected with their gustatory nerves or 

 take just the opposite view, which seems more in accord with 

 the evidence, and look on the nerve fiber as taking the initiative 

 and producing the bud on reaching the surface, the order in 

 which the nerves are arranged here would seem to indicate the 



mm. 



