60 



FREDERICK TILNEY AND LUTHER F. WARREN 



paraphysis shows no features of sensory function. Of these 

 three encephalic diverticula from the roof-plate in Saurians, 

 the parietal eye alone seems to have had ancestral sensory 

 function (fig. 26). 



In a later communication, combating the contention of Klinck- 

 owstroem 207 to the effect that the evolutional process observed 

 in Anguis is normal and more primitive while that in Lacerta 

 is a simple modification of this . primitive form, Beraneck 25 pro- 



Fig. 



The epiphyseal complex in a 27 mm. embryo of Anguis fragilis, ac- 



cording to Beraneck, 1892. 



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

 benularis; Npar., nervus parapinealis; Pa., parapineal organ; Ep., pineal organ; 

 Sch., pars intercalaris posterior; Cp., commissura posterior. 



posed this question, "If in Anguis the parietal eye is only a 

 differentiation of the distal extremity of the epiphysis, how in 

 Lacena does this visual organ develop parallel to the epiphysis 

 and not dependent upon it?" Beraneck maintains that Klinc- 

 kowstroem escapes the difficulty proposed by this question in 

 claiming that the pineal eye of Iguana and Lacerta upon the 

 one hand and Anguis upon the other take origin from different 

 parts of the epiphyseal evagination. Beraneck formulates the 

 hypothesis that the parietal eye and epiphysis represent in 



