THE PINEAL SYSTEM OF RHIP IDOGLOSS A 283 



wall was folded, and from the extremity of this portion a cord, which he 

 regarded as the nerve, coursed forward to the parietal eye. Owsjannikow, 

 however, considered that this cord consisted of connective tissue rather 

 than of nerve-fibres. The parietal organ in Spencer's specimen was a 

 slightly flattened hollow vesicle which was elongated in the antero- 

 posterior direction. No distinction in the structure of different parts 

 of its wall could be recognized, neither lens nor retina being distin- 



Fig. 194. — Vertical Section through the Pineal Eye of a Skink, showing 

 the Lens, Retina, Nerve, and Pigment Cells. 



It will be noted that there is a considerable amount of pigment in the epidermis 



and subepidermal tissue lying over the pineal organ. 



(Drawn from a photograph — J. Calvet.) 



guishable. The walls throughout were composed of cells of approximately 

 equal length, and the inner ends of these cells bore long cilia which 

 projected into the cavity of the vesicle. No pigment was present. The 

 lower wall of the vesicle, moreover, showed on its inner aspect a small 

 invagination which Spencer took to be a remnant of the primary con- 

 nection of the lumen of the parietal organ with that of the epiphysis. 



