NERVUS TERMINALIS IN AMIA 



75 



When this ventro-median wedge is traced posteriorly into the 

 cranial cavity it furnishes the fibers for a separate bundle (fig. 

 11) which passes to a more median position. This bundle has 

 the ganglion cells already referred to, occasionally along its 

 course, as figs. 11 and 12 show. However, there are variations 

 with regards to the distinctness of the nervus terminalis in differ- 

 ent cases as is well shown on the opposite, or left, side of tnis 

 same fish where it is never more distinct within the cranial cavit v 

 than is indicated in fig. 10. Consequently, I was able to trace 

 a nervus terminalis on the left side of this specimen, only by a 

 more or less detached wedge of the median half of the olfactory 



Tierire 

 ■"nervus te rmiTidks 



Fig. 11. From same series as fig. 10, but farther caudad within the cranial 

 cavity. The nervus terminalis is distinct and shows a ganglion cell. X 210. 



nerve, in which the characteristic large ganglion cells were found 

 occasionally. It may be mentioned in this connection that I 

 found a separate bundle of the left olfactory nerve in this fish, 

 located on its dorso-lateral side at the level of the eye-muscle 

 canal, but no ganglion cells were found along its course from the 

 time it separated from the olfactory nerve until it reunited with it. 

 On the right side, the farther the nervus terminalis is traced 

 caudad within the cranial cavity in this Weigert series, the 

 farther it becomes separated from the main olfactory nerve 

 (fig. 12). This figure is drawn at a level where it includes a large 



