120 



FKKDKHirK TILXKV AND U THER F. WAKIM.X 



early worker-. These researches include those of Beranock 

 ('87)-' in AtHjuix and Lncertn; Franc-otto ('S7) 127 in AtKjni*; 

 McKay ('88)'- >; '" in Grammatophora and Hinnlid; Strahl and 

 Martin ('88) 383 in Lucnia, and Hitter ('91) 332 in Phnjin^nini. 

 There is a general agreement regarding the histological structure 

 of the retina among saiirians, and the following layers have 

 been identified by most of the investigators mentioned: 



Fi><;. '") The structure of the retina in the pineal eye in Sphcnodon punrtatum 

 accordiiiK to Spencer, 1886. 



1. Aii inner layer of long, cylindrical cells, called the rods or 

 rod-like bodies of Spencer 366 or the cellule* (xilonncts of Fran- 

 cotte. 1 - 7 In these cells pigment occurs. 



'_'. An inner layer of cells, called the 'couche cellulaire interne' 

 by l''raiicotte. 127 This consists of round cells with a large round 

 nuclei. Ritler'-' 1 '-' distinguishes 1\vo types of nuclei in this layer, 

 najnol} r , those which are round and small and those which are 

 oval and long. 



