THE CRANIAL GANGLIA IN AMEIURUS 



383 



The visceral ganglion of the IXth nerve seems to be a pure 

 placodal ganglion. The first two epibranchial ganglia of the Xth 

 resemble the IXth, but may possibly contain lateral mass cells. 

 The last two epibranchial ganglia of the Xth are quite small and 

 combine with the large lateral mass portion so that the posterior 

 portion of the visceral Xth is largely lateral mass in origin. These 

 relations are shown in table V : 



TABLE V 



Showing the source of the various components of the cranial ganglia of Ameiurus. 

 The presence of any given component is indicated by the word present. 



In this table the general cutaneous, general visceral and acus- 

 tico-lateralis portions of the Xth are placed over the last two 

 epibranchial ganglia not so much to indicate their segmental 

 position as because they occupy this relative position. The later- 

 alis Xth extends however much posterior to the visceral portion. 



A comparison of this table with table II compiled from Herrick's 

 work on Ameiurus (p. 321) shows that the ganglia are as discrete 

 in their mode of origin as are the components of the adult ganglia 



