462 



J. B. JOHNSTON 



c.c. 





64 





Fig. 64 Rat, sagittal section slightly inclined to the right at the dorsal edge. 

 The section crosses the median plane at the point x. Above this point the sec- 

 tion cuts the right fornix coliunn, below it cuts the left. In front of the fornix 

 columns (to the right) is the large-celled nucleus of the septum; behind, the 

 small-celled nucleus in which the commissura hippocampi is imbedded. >The 

 continuity of the two nuclei between the fornix columns (as well as lateral to 

 them) is interesting just here because there is seen at the same time a continuity 

 with the nodulus marginalis to which the tela is attached at m. It is clear that 

 this nodule is composed simply of the cells nearest the dorsal margin of the lamina 

 supraneuroporica and that the whole commissure system has developed in the 

 cell-mass between this and the level of the neuroporic recess. 



Figs. 65 to 70 Rabbit, six transverse sections rostral to the interventricular 

 foramen. Weigert stain. 



Fig. 65 Section through the rostral end of the hippocampus near the peduncle. 

 On the right side the hippocampus and the cortical layer of the tuberculum are 

 shown in black. Note the olfacto-cortical fibers rising close past the caudate 

 nucleus and the olfactory commissure bundle. Compare figure 27. 



Fig. 66 Section just in front of the genu. On the right the indusium is shown 

 (black) bending about the genu. Note the prominent band of precommissural 

 fibers which mark the zona limitans. Compare figures 27 and 42. 



