Herrick, A/orfi/io/oiiy of \ci-i'oiis •'^V-'^fon. in 



It seems probable that the projecting portion of the ha- 

 bena has been frequently mistaken for the epiphysis. The 

 plexvis chorioideus which protrudes, and the fillet of epi- 

 thelial cells forming a part of the peduncle of the epiphys 

 constitute a body which may easily be regarded as an imper- 

 fectly developed pineal body. It would be possible to inter- 

 pret in this way the description given by Stieda of the epi- 

 physis of turtles. He says: " Eine besondere Epiphysis- 

 cerebri existirt bei der Schildkrote nicht; das kleine keil- 

 formige Korperchen, welches den dritten Ventrikel und das 

 Zwischenhirn von oben deckend zwischen die hinteren Ab- 

 schnitte des Lobi hemispha^rici eingeschoben ist, zeigt sich 

 bei mikroskopischer l-ntersuchung nur als Plexus chorioideus 

 des Zwischenhirns oder des dritten Ventrikels. Nervose 

 Elemente sind nicht zu erkennen.'' (Ueber den Bau des 

 Centralen Nervensystems der .Schildkrote, p. 68.) 



The epiphysis of the lizard has already been described. 

 Its general histology is well shown by Fig. 7, Plate III. In 

 longitudinal sections in the horizontal plane the structure 

 has an unmistakable resemblance to that of an undeveloped 

 retina, as seen in the eye of larvae of amphibians. The pig- 

 ment clothes the inner wall facing the lumen. Then follows 

 a series of cylindrical cells, whose processcA connect with 

 oval cells similar to those of the ganglionic layers of the 

 retina. While it is impossible to trace direct nervous con- 

 nection with the base, fibres can be followed from the gan- 

 glionic layer to the walls of the capsule. There is a lobe 

 of the plexus cephalad and a number of vessels caudad in 

 the sling of connective tissue supporting the organ. 



Reference is here made to the valuable paper by Eh- 

 lers('), in which a critical review of previous literature of 

 the epiphysis may be found. 



In spite of the great prolongation of the peduncle of 

 the epiphysis in sharks and the cephalad position of the 



I E. Ehlers, Die Epiphysis der Plagiostomen, Zeitschrift f. Wissensch. Zoologie, 

 XXX, Suppl . 



