The Pineal Region in Teleosts. 



341 



Fig. 17. Dorsal aspect of the brain of adult Opsanus. X 7. 



Superior Coinmissure. This remains as in the preceding stage. 



Posterior Commissure. The fibers of the commissure are now 

 separated into bundles by deUcate septa continuous with the 

 underlying endyma. 



Velum Transversum. The pedicle of the median lobe now ex- 

 tends backward to the level of the superior commissure. As a 

 consequence of the backward growth of the velum the dorsal 

 part of the diencephalic cavity has been reduced to a mere cleft 

 extending transversely between the intermediate tubercles. 

 The epithelium of the lobules is everywhere elevated into tufts 

 supported by vascular connective tissue. 



