Herrick, Morphology of Brain of Bony Pishes. 343 



apex, forms an interlacing layer, which encloses the fore part 

 of the lobe as in a sheath, and envelops small rounded masses 

 of coarse granular neuroglia, which may be looked upon as 

 representing the glomeruli in the bulbus olfactorius of mam- 

 malia, described by Meynert. 



" Larger cells are seen to occupy the inner edge of this 

 layer of nerve fibres, where it begins to pass over into the 

 stratum of finely granular neuroglia above described; at this 

 part the neuroglia is coarser, and the cells in question occupy 

 spaces therein in the same way that the small cells do in the 

 central group. These cells are mostly tripolar, with some- 

 times one and sometimes two broad protoplasmic processes, 

 the others being fine and probably axis-cylinder prolonga- 

 tions. They measure .013 millim. long by .010 broad, the 

 nucleus measuring .007 by .006 millim.; some have a dis- 

 tinct spot-like nucleolus, which, however, in many speci- 

 mens, cannot be so easily distinguished. Besides these, 

 other unipolar cells occur in which the protoplasm greatly 

 preponderates, and where the nucleus is not much larger 

 than that of the small cells of the central group 



"In addition to the larger cells, which, as before men- 

 tioned, occupy the border of the layer of fibres, some of these 

 fibres themselves show cell-like swellings in their course, 

 which somewhat resemble the cells described by Meynert in 

 the glomeruli olfactorii of the human subject. These cell- 

 like swellings in the course of the fibres are like some kinds 

 of bipolar cells: they have large oval nucleoli and conspicu- 

 ous nucleoli." 



We dissent completely from the author's views respecting 

 the cavities within the lobe and regarding them as products 

 of shrinkage. Especially the curious suggestion as to the 

 origin of epithelium seems uncalled for. 



The only data at hand on the development of the olfac- 

 tory in fishes are meager. I quote from Holt as follows: 



In the herring at one day (Holt, p. 480, Plate XXIX, 

 Fig. 2, and 5 ol.) " the nasal sacs are closely apposed to this 



