STRUCTURE OF PARIETAL ORGAN OF SPHENODON 



/Psc p.s.c. 



255 



s br.a.p.a. 



Fig. 181. — Section of the Retina of the Pineal Eye of Sphenodon punctata. 



(After Dendy.) 



br. a.p.a. : branch of anterior m.l.e. : membrana limitans externa, 



pineal artery. m.l.i. : membrana limitans interna. 



c.i. : capsula interna. n.r.f. : nucleus of radial fibre. 



c.t.f. : connective tissue fibre. pig. : pigment. 



g.c. : ganglion cell. pig. c. : pigment cell. 



l.n.f.p.e. : layer of nerve-fibres p.s.c. : processes of sensory cells, 

 of pineal eye. 



Fig. 182. — Parietal Eye of a 76-MM. Embryo of Anguis fragilis. (After 



(Beraneck.) 



Pigment is present in the central and deep part of the lens. The lens is very wide, 

 and is continuous at its periphery with the retina. The nerve-fibre layer of 

 the retina is interrupted below the central mass of pigment in the lens. 

 Pigment is absent in the corium and epidermis of the tissues lying superficial 

 to the eye. 



