404 Journal of Comparative Neurology and Psychology. 



cated near the outer margin of the epithelium. In a few cases in 

 GoLGi preparations, central processes of neuroblasts were seen 

 extending towards the brain wall into elevations of the epi- 

 thelium (Fig. 7). 



Formation of Cojmection hetivecn the Nasal Epithelium and 

 the Brain Wall. — In slightly older embryos several cellular 

 cords may be seen projecting a short distance into the meso- 

 derm. The cords may be distinguished from the surrounding 

 mesoderm by their compactness and their continuity with the 

 epithelium. These cords are directed toward the brain (Fig. 11). 



^'x-^- 



'^ST^, 



P 



M " 



FB 



Fig. II. Section of a 12 mm. embryo, showing the development of the 

 "elevations" into short cords {Cd) projecting towards the brain wall. F. B., 

 wall of forebrain ; M., mesoblast ; N. P., lumen of nasal pit. 



In embryos of twelve or thirteen millimeters length, these 

 cords become much longer. As yet, there is no connection 

 with the brain. In none of the specimens stained by iron hae- 

 matoxylin, have fibers been observed. However, dissections 



