400 Journal of Comparative Neurology and Psychology. 



siderably elongated, conical elevation is present on the periphe- 

 ral end of the cell. In these cases the cell body is removed 

 somewhat from the outer margin of the epithelium and the cen- 

 tral fiber is well developed. All intermediate stages, from a 

 spherical cell through a pear-shaped cell, from the apex of which 

 a fiber passes toward the central border of the epithelium, to a 



@-E. 



Fig. 4. A, Longitudinal section of a swine embryo, 13 millimeters in 

 length, through the nasal pit. E, eye. X S. 



£, Portion of olfactory epithelium of A [x) showing developing nerve cells 

 (A') and supporting cells (5). A'. /"., nasal pit. X 93M- GOLGI preparation. 



bipolar cell, are found (Fig. 3). These cells conform very well 

 to developing neuroblasts described by His, and called by him 

 germinating cells. Not until some time after this is there any 

 structure present between the epithelium of the olfactory pit 

 and the brain wall, which might be considered to be the anlage 

 of the olfactory nerve. 



Fig. J'. .Section of olfactory epithelium of a swine embryo, 17 millimeters 

 in length, showing developing nerve cells (N). Goi.Gi preparation. X 93/^- 



By the use of the Golgi method, both the developing 

 nerve cells and supporting epithelial cells are impregnated. 

 The latter are quite irregular in outline, while each of the for- 

 mer has an enlarged cell body which tapers at either the peri- 

 pheral or the central pole of the cell or at both poles into a 

 slender unbranched process. In Golgi preparations, the de- 



