237 



The identification of the tractus olfacto-habenularis (tr. taeniae) 

 is necessary to complete this account. It is very easily traced (Figs, 

 6 — 21, 27). It is found in the dorsal portion of the broad fiber area 

 which Kappers labels tr. strio-thalamicus et olfacto-hypothalamicus. 

 The fibers are diffusely related to the tractus strio-thalamicus so that 

 their place of origin can not be clearly made out in Weigert sections. 



tr. taen. 



Fig; 6. 



Fig. 7. 



r. pal 



It certainly comes from the basal region as in other fishes. I believe Kap- 

 pers' first description of this in Galeus is correct. It arises from the whole 

 olfactory area, both medial nucleus at the rostral end of the brain 

 and the lateral nucleus, and courses caudad beneath the ventricle re- 

 lated to the tractus strio-thalamicus. In fishes generally the so- 

 called tractus taeniae arises not only from a specific nucleus taeniae 

 situated caudo-laterally, but from the medial olfactory nucleus and the 



