45 



n. nov. 



!h 



^-4 



n. nov. 



KuPFFER in the amphibian brain ^). It is more ventral in position 

 than his ementia pallii medialis. 



The picture of a cross-section of the prosencephalon of Squalus, 

 in the plane of the nerve terminals (Fig. 10 A) , shows a median in- 

 folding of the pal- 

 lium from the dorsal 

 surface uniting with 

 an elevated mass of 

 cells from the ven- 

 tral side. The whole 

 forms a thick septum 

 dividing the brain 

 cavity into right and 

 left ventricles. There 

 is on this septum a 

 dorsal and a ventral 

 protuberance ; the 

 fibers of the new 

 nerve terminate in 

 the region between 

 the two and in the 

 dorsal part of the 

 lower eminence. 



Peripheral 

 Distribution. — 

 The study of serial 

 sections shows, that 

 the fibers of the new 

 nerve are mainly 

 (but not entirely), 

 distributed to the 

 olfactory membrane 

 in the antero-lateral 

 portion of the ol- 

 factory cup. The 

 chamber of each ol- 

 factory cup is a continuous one, but it is incompletely divided into 

 two portions by membranous flaps, attached to a firm ring surrounding 





/^ 



^^ 



:^? 





n. nov. 



B 



Fig. 10. A, cross-section of the brain of Squalus acan- 

 thias, 150 mm long, showing the position of the main branches 

 of the new nerve. B. section of the olfactory cup of Squalus 

 acanthias, showing in a general way, the new nerve as traced 

 into the nasal membrane. Under higher power, smaller fibers 

 were traced between the folds and into the epithelium. 



1) Handbuch der vergleichenden und experimentellen Entwickelungs- 

 lehre der Wirbeltiere, Lief. 14 und 15, 1903. 



