132 



FREDERICK TILNEY AND LUTHER F. WARREN 



Accessory pineal and parapineal organs in Reptilia. A number 

 of observers have reported the appearance of accessory struc- 

 tures in connection with both the pineal and parapineal organs. 

 Such observations have been made by Spencer ('86) 366 in Plica 

 umbra; by Duval and Kalt ('89)" in Anguisfragilis; by Carriere 57 

 in 1890; by Prenant 311 in 1893-94-96; by Leydig 237 in 1890-91, 

 and by Francotte 130 in 1896. Accessory organs were also found 



Fig. 68 The corneal scale in Calotes, according to Spencer, 1886 



in Lacerla vivipara by Burckhardt 46 in 1894; by Francotte 130 in 

 1896; by Klinckowstroem ('94) 209 in Iguana, and by Studnicka 

 ('93) 384 in Pseudopus pallasi. Accessory epiphyseal organs may 

 arise either from the lateral wall of the end-vesicle of the pineal 

 organ or the under wall of the parietal eye. There are two 

 types of accessory organs: 1) accessory pineal organs, and 2) 

 accessory parietal eye organs. The following are the possibili- 

 ties for accessory pineal organs : 



