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FRED W. STEWART 



of the olfactory sac, and statements made in this regard are 

 admittedly on the basis of limited material. In the rat no 

 evidence of a neural-crest origin for cells of the nervus terminalis. 

 as presumed by Johnston ('09), has been obtained. They, 

 instead, apparently arise from a proliferation of cells of the septal 



N.C. R.O. 



18 



Fig. 18 Rat embryo, 13£ days, Bouin's fluid. Neuroblasts scattered along 

 the ramus ophthalmicus V. Projection drawing, X 500. 



aspect of the olfactory sack, including the epithelium of the 

 vomeronasal organ (fig. 19). The possibility suggested by 

 Hardesty ('14), that the ganglion cells of the nervus terminalis 

 may arise as a forward extension from the cervical sympathetic, 

 is scarcely tenable. Cells appear among the fibers of the nervus 

 terminalis (of course, not differentiated from olfactory fila) before 

 there is any forward extension whatever from the cervical sympa- 



