THE PINEAL BODY 139 



parietal eye has the form of a dorsoventrally compressed sac 

 which has a lens and well-marked retina, the latter has a double 

 layer of well-pigment ed cells. Rod cells also are present. The 

 entire parietal organ is enclosed in a connective-tissue capsule. 



ANGUIDAE. 1. Anguis fragilis. Leydig ('96) ; 239 deGraaf 

 ('86) ; 155 Spencer (86) ; 368 Beraneck ('92) ; 23 Hanitsch ('88); 169A 

 Strahl and Martin ('88) ; 383 Francotte ('96) ; 130 Owsiannikow 

 ('88) ; 295 Duval and Kalt ('89;) 99 Carriere ('90) ; 57 Prenant, 

 ('95) , 312 and Studnicka ('93). 384 



The epiphysis in this species consists of a proximal and a 

 distal portion. The end portion of the epiphysis is deeply 

 pigmented. The parietal eye is connected by a connective- 

 tissue strand to the epiphysis. The parietal nerve is present 

 only in embryos and arises from the ganglion habenulae. The 

 parietal eye is lenticular in form, dorsoventrally flattened, and 

 has a deeply pigmented retina. The lens is bi-convex and plano- 

 convex. The lumen contains a coagulated substance with a 

 syncytium. There is a well-developed capsule. Accessory 

 organs are common. The position of the eye is in a parietal 

 foramen. The parietal cornea, pit, and spot are present. 



2. Varanus bengalensis. Spencer ('86). 368 The pine'al organ 

 has a distal and proximal portion and there is no parietal nerve. 

 The parietal eye is present and contains a lumen. The retina 

 contains rod cells and several layers of smaller cells. The lens 

 is convexo-concave. The parietal foramen is of large size. 

 There is a capsule, a parietal pit, and a parietal spot. 



3. Varanus nebulosus. Leydig ('91). 238 In this species the 

 pineal organ is as in other forms, but there is no end-sac. The 

 parietal eye is pyriform but there is no distinct retina. 



4. Pseudopus pallasi. Owsiannikow ('88) ; 295 Hoffmann 

 ('90), 187 in Bronns "Klassen and Ordnungen." 



In this form there is a well-developed lens, retina, and vitreous. 

 Studnicka 386 in 1895 described the conditions as follows: There 

 is a complete pineal organ with an end-vesicle, a stalk, and 

 proximal portion, the latter being the epiphysis. This is con- 

 nected with the brain-roof by a secondary stalk. The parietal 

 eye is semiglobuiar in shape. There is a lens and retina, the 



