THE PINEAL BODY 



61 



Lacerta two distinct evaginations of the thalamencephalic roof. 

 If they appear to be different in Iguana and Anguis that is due to 

 secondary modifications of this region. The evolution of the 

 parietal eye in Iguana is intermediate between the conditions 

 observed in Lacerta and Anguis. In his conclusion, Beraneck 

 emphasizes his belief that the embryonic facts contradict the 



Fig. 26 Frontal section showing epiphyseal complex in a 26-day old Iguana 

 tuberculata, according to Klinckowstroem, 1894 



Pf., paraphysis; Ds., dorsal sac; Npar., nervus parapinealis; Ep.,, proximal 

 portion of pineal organ; Ch , comrr.issura habenularis; A/., midbrain 



epiphyseal origin of the parietal eye in Saurians and confirm 

 the hypothesis of its embryonic individuality. Leydig 288 in 

 1891 confirmed the view of Beraneck in Lacerta agilis. Dendy 8 ' 

 also states that the parietal eye and what he calls the parietal 

 stalk arise from two distinct evaginations in the roof-plate of 

 the interbrain. By parietal stalk, Dendy refers to the portion 

 of the epiphyseal complex here referred to as the pineal organ. 



