NERVUS TERMINALIS IN AMIA 



97 



forebrain, of the dorsal sac, and of that side of the diencephalic 

 sacs farthest from the brain wall. The ental side (toward the 

 brain) of the diencephalic sacs is made up of delicate flattened 

 epithelial cells, as Kingsbury ('97, a) has noted. Also, he has 

 pointed out the fact that the high columnar epithelial cells of the 

 pallium and diencephalic diverticula are glandular in appearance 

 and that they have a more copious blood supply than the flat cells 

 on the ental side of the diencephalic sacs. 



Favorable fixations and staining in iron hematoxylin show that 

 these columnar cells are ciliated (fig. 28) with from three to six 

 long stout cilia to each cell. Portions of the live epithelium 

 mounted in normal saline solution show that the cilia are active 

 in producing motion in the encephalic fluid. Strips of the epithe- 



Fig. 28. Section of the membranous pallium of the forebrain of adult Amia. 

 Shows the motile cilia, the granular contents of the columnar epithelium and its 

 cuticular border. Two "mast" or wander cells are shown between the cells of the 

 epithelium proper. Iron hematoxylin stain. X 444. 



lium running parallel with the long axis of the brain show by the 

 motion of the blood corpuscles which have escaped from the 

 vessels, that the general direction is anterior in the common fore- 

 brain ventricle. Strips cut from the ventricular walls of the 

 forebrain showed that there is ciliary action by its cells also, 

 producing motion rostrad along the slit between the halves of the 

 prosencephalon. Likewise, there is ciliary action on the walls 

 of the rhinoccels. The few experiments made seem to show that 

 the return path of the encephalic fluid runs laterally from the 

 rhinoccels and posteriorly along the lateral everted portion ( Kappers 

 '07) of the forebrain. The cilia have basal bodies and the free 

 borders of the epithelial cells possess a cuticula which is striated 



