THE PINEAL BODY 



63 



The development of the epiphyseal complex in Ophidia, Chelonia, 

 and Crocodilia. The embryonic description which holds good 

 for the more primitive forms of reptiles must be much modified 

 in dealing with the more highly organized and modern forms of 

 this class. Hoffmann 186 showed that in these reptiles the anlage 

 of the epiphyseal complex is laid down as a single evagination 



AT. , . 



Fig. 29 The epiphyseal complex in Tropidonotus natrix, according to Stud- 

 nicka, 1893. 



Pf., paraphysis; Ds., dorsal sac; Ch.. commissura habenularis; Ep., proximal 

 portion of pineal organ; R., recessus pinealis. Cp., commissura posterior; M., 

 midbrain. 



from the roof-plate immediately anterior to the posterior com- 

 missure. This hollow evagination is ultimately transformed 

 into a solid body. Such a transformation has been shown by 

 Ley dig 210 and Studnicka 389 in Tropidonotus (figs. 29 and 30). 



Fig. 27 The epiphyseal complex in a 31 mm. embryo of Gehyra oceanica, ac- 

 cording to Stemmler, 1900. 



Pf., paraphysis; V., velum transversum; Ds., dorsal sac; Ch., commissura 

 habenularis; Ep., pineal organ; Cp., posterior commissure; M., midbrain. 



Fig. 28 The epiphyseal complex in a 33 mm . embryo of Platydactylus muralis, 

 according to Melchers, 1899. 



Pf., paraphysis; Ds., dorsal sac; Ch., commissura habenularis; Ep., pmea 

 organ; Sch., pars intercalaris posterior; M, midbrain. 



