THE OLFACTORY NERVE OF LEPIDOSTEUS 125 



present are represented on the other side, for two reasons. As 

 already stated, cross-sections are not favorable for the differen- 

 tiation of these cells from others, and, in the second place, it is 

 not easy to find them all, scattered as they are shown to be in the 

 previous stage drawn (fig. 12) through the whole ventral portion 

 of the nasal capsule. A very few cells were found proximally 

 along the ventro-median border of the olfactory nerve not far 

 from the nasal capsule (fig. 14.) 



In a young T.epidosteus 85 mm. in total length cut sagitally, 

 the central ganglion of the nervus terminalis was found 3 mm. 

 rostral of the olfactory bulbs, a distance of 15 mm. posterior from 

 the nasal capsules at a point slightly anterior to the masticating 

 muscles of the jaw. The olfactory nerve on this (the right?) 

 side of this fish has three peripheral ganglia with a total number of 

 cells about equal to those in the central ganglion just mentioned. 

 One is located 2 mm. posterior to the olfactory capsule, and the 

 other two near each other, 5 ram. caudal of the olfactory capsule. 

 No ganglion cells were recognized within the confines of the nasal 

 capsule in this instance. It will be noted that there is a space of 

 10 mm. at about the middle of the length of the olfactory nerve, 

 now some 18 nun. in total length, in which no ganglion cells were 

 foimd. 



The central ganglion on the other olfactory nerve of this 85 mm. 

 fish was recognized in the same position as above indicated, but 

 peripherally there was but a single ganglion found. It is located 

 1 mm. caudal to the olfactory capsule. Its size was estimated to 

 be equal to the three combined peripheral ganglia of the opposite 

 nerve. The olfactory capsule was so disturbed in the making of 

 the sections that it was not possible to determine whether any 

 ganglion cells were included within it. 



In a transverse series of a fish about 90 mm. in length the centi-al 

 ganglia were recognized at a distance of 2 mm. anterior to the 

 olfactory bulbs. In a specimen about 125 mm. in length the 

 central ganglion was found on one side, situated 3 nun. rostral of 

 the olfactory bulbs (fig. 15) . This ganghon was estimated to ha\e 

 about 100 cells, occupying a \'entral position on the olfactory ner\'e 

 (fig. 16) between a large l)lood vessel laterally and a mass of carti- 



