xii Journal of Comparative Neurology. 



bellum, which is supposed to be cut longitudinally with the different ele- 

 ments drawn separately in the different portions. A correct view would 

 necessitate the superposition of the several portions upon each other. A 

 represents two Purkinje cells with their axis-cylinder processes passing 

 into the central white layer, B, large stellate cells of the molecular layer, 

 C, large stellate cell of the granular layer, D, granules or small stellate 

 cells of the granular zone, E, neuroglia cells. The small stellate cells of 

 the granular layer are said by Cajal to possess small branching processes 

 as well as axis cylinder processes which pass to near the surface of the 

 molecular layer and there bifurcate. The basket-like projections from the 

 axis-cylinder (?) of the large cells of the molecular layer are well seen in 

 the figure ; they envelope the body of the cells of Purkinje. 



Van Gehuchten summarizes his results on the olfactory as follows : 

 "In mammals the lateral cerebral ventricle is prolonged into the olfactory 

 bulb. The ventricle is lined with an epithelium similar to that of the spinal 

 cord. In the lower part of the figure (Fig. 4.) the mucous olfactory layer 

 IS represented (niti). In this layer I find, in harmony with Cajal, two 

 sorts of cells, — epithelial cells {ce) and bipolar cells {ch). The latter are 

 the nervous elements with an axis-cylinder process (olfactory fibre) which 

 traverses the submucous layer and cribriform plate of the ethmoid and 

 terminate in free fibrils within the glomernles The same glomerule re- 

 ceives a protoplasmic process from a large cell called from its form mitral 

 cell. The protoplasmic process terminates in the glomerule with free 

 fibrils. The body of the cell gives off" numerous other protoplasmic pro- 

 cesse-; and an axis cylinder extending toward the cerebrum! This is 

 therefore another illustration of the transmission of nervous stimuli 

 by contact. It will be observed that this description distinctly departs 

 from the view that the axis cylinder alone is of a nervous character. The 

 writer has called attenti'-n to the fact that the glomerule is a station where 

 the nerve path losses its integrity by the fusion of the sheath and has 

 suggested that it may be a point for the elaboration of new material, as 

 indicated by the great number of Deiter cells and nutrient bodies collected 

 about the glomerule. It is not impossible that the fibrils demonstrated in 

 the glomerule may sustain some such intrerpretation and that a delicate, if 

 undemonstrable, connection exists between the mitral cells (specific olfac- 

 tory cells) and the processes of the epithelium. In general, this scheme 

 for the olfactory is hard to bring into accord with the view lately advo- 



