THE OLFACTORY NERVE OF LEPIDOSTEUS 123 



methods we have had to rely for recognition on the larger size 

 and the deeper staining of the cj'toplasni in hematoxylin prepa- 

 rations. In sagittal sections the neurological characters of vesic- 

 ular nuclei and of cytoplasmic granules appear fairly well- 

 marked. The granules (Nissl bodies) are more apparent than in 

 transverse sections, since they are more numerous in the ends 

 of these cells, which are elongated in the direction of the axis of 

 the olfactory nerve. A slight increase in the number of cells at 

 the posterior part of the nasal capsule might be designated a 

 peripheral ganglion (fig. 12), 



We have been fortunate enough to catch a few young Lepidos- 

 teus of varying sizes larger than the emln-yos just described, dur- 

 ing our stay at the Ohio State I'niversity Lake Laboratory' at 

 Cedar Point on Lake Erie the past summers. The young are 

 solitary in their habits and it has not been possible to secure 

 them in large numbers for exhaustive neurological technique as 

 with Amia ('10) and Ameiurus (Brookover and Jackson '11). 

 We have studied transverse sections of a specimen 43 nun. long. 

 A flat reconstruction of the -proximal portion of the olfactory 

 nerves as seen from the ventral side shows the position of the 

 ganglia and the approximate number of cells is indicated by the 

 dots (fig. 13.) There is a slight asymmetry in the form and posi- 

 tion of the two ganglia, as might be expected where organs are 

 slender, and this lack of synunetry was noted in specimens older 

 and younger. The ganglia are rostral of the brain a distance of 

 between one and two millimeters, the total length of the olfac- 

 tory nerve being about 8 mm. at this age (fig. 13). 



A flat reconstruction of the rostral end of the olfactory nerves 

 and the nasal capsules of this 43 mm. specimen (fig. 14) as seen 

 from below, shows a few cells (indicated by dots) that would seem 

 to belong to the peripheral ganglion of the nervus terminalis 

 mentioned in previously-described stages. These cells are located, 

 for the most part, near the posterior end of the nasal capsule 

 where the olfactory fibers begin to spread for their final distribu- 

 tion in the capsule. One side of the specimen was defective from 

 interference of ossification in sectioning and no cells are indicated 

 in the drawing (fig, 14); probably, moreover, not all the cells 



