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CHARLES BROOKOVER 



pigment in this location. However, as the young fish grows, bone 

 and cartilage intervene between the skin and the pineal stalk. The 

 distal end of the pineal stalk in the adult fish is slightly enlarged 

 (fig. 30) and adheres to the cartilage on the roof of the brain case. 

 The nerve fibers and cells of the adult pineal stalk of Amia were 

 found to be particularly susceptible to methylen blue used intra- 



cereb. optic lobe 



habenul 



dorsal sac 



epiphysis 



paraphysis tubes 



paraphysis duct 

 velum transversum 

 pallial fold 



rhinocoele 



ant. com. 



olfactory bulb 



Fig. 30. View of the left half of the anterior part of the adult brain of Amia as 

 seen from the median plane, to show the relation of the pineal stalk, the para- 

 physis, and the diencephalic sacs to the brain ventricles. Partially schematic 

 from camera lucida outlines. X 6. a. d. s., anterior diencephalic sac; ant. com., 

 anterior commissure; cereb., cerebellum; hyp., hypophysis; z. I., inferior lobe; 

 mam., mammillary body; m. I. dorsal sac, median and lateral portions of dorsal 

 sac; op. n., optic nerve. 



vitam. A number of fine impregnations were procured by inject- 

 ing methylen blue through the ventral aorta just anterior to 

 the heart. Fig. 33 shows a drawing made from such a prep- 

 aration mounted without sectioning and represents the pineal 

 stalk at about the middle of its length. The longitudinal nerve 

 fibers already mentioned as occurring in Golgi and Cajal prepara- 



