The Pineal Region in Teleosts. 



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Fig. 1. Reconstruction of the pineal region of an Opsanus embryo of 11 mm. 

 H.E.C., series no. 121. X 167. A part of the right wall of the ventricle has been 

 removed and the paraphysis has been sectioned in the median plane. 



has also helped in the identification of the regions in the smallest 

 embryos. As the starting point, there was selected from the series 

 an embryo in which all the structures pecuUar to the pineal region 

 could be identified beyond question. Each structure was then 

 traced back through smaller and smaller embryos to the stage 

 in which it was first appairent. 



The material basis for most of the observations recorded is 

 Opsanus (Batrachus) tau, the toad-fish, a teleost represented in 



