THE PINEAL BODY 



57 



it was rather a subdivision of a single evagination from the roof- 

 plate which gave rise to the parietal eye; more recently, however, 

 the opinion has been expressed by several observers, that the 

 parietal eye owes its existence to an anlage quite independent 

 from that of the pineal organ and situated anterior to the latter 

 in its point of development from the roof-plate of the inter- 

 brain. The fact that the parietal eye was not the constricted 

 end of the epiphysis, but was independently connected by 



Fig. 22 Anlage of the epiphyseal complex in an 11 mm larva of Bufo vulgaris 

 according to Beraneck, 1893. 



Po., pineal organ (end-vesicle); Ep., proximal portion. 



means of a nerve of its own to the roof of the brain, was shown 

 conclusively 'by Strahl and Martin 383 as well as Beraneck, 23 who 

 was first to call attention to the nerve fibers connecting the 

 parietal eye with the brain, namely, the parietal nerve. Having 

 thus dispensed with the idea that the parietal eye was merely a 

 constricted portion of the end of the epiphysis proper, it re- 

 mained for subsequent investigation to demonstrate the actual 

 process by means of which the parietal eye arose. Advocating 

 the view that the anlage of the epiphyseal complex in Reptilia, 

 and particularly in the Saurian and Prosaurian forms, is an 

 evagination subdivided into an anterior and a posterior compart- 



