THE PINEAL BODY 



109 



16. Belone acus. Studnicka ('96). 383 In this species there is 

 a long, tubular stalk. Ependymal cells form the walls of this 

 stalk and have an arrangement reminiscent of the retinal sen- 

 sory cells of the retina of Petromyzon especially of the region of 

 the large end- vesicle (fig. 57). 



17. Cyprinus carpio. Studnicka ('96). 383 The end-vesicle 

 in this form is a circumscribed dilatation and has a thin, hollow 



Cr 



Hn 



Ch 



Fig. 57 The epiphyseal complex in Belone acus, according to Studnicka, 1896. 



Ls., lamina terminalis; Pf., paraphysis; D., dorsal sac; Ch., commissura ha- 

 benularis; R., proximal portion; Po., pineal organ; Cp., posterior commissure; 

 M., midbrain. 



stalk, in the dorsal wall of which there courses the tractus 

 pinealis. 



18. Carassius auratus. Studnicka ('96). 386 The pineal organ 

 in this form is tubular throughout its entire extent. There is a 

 tractus pinealis as usual in the stalk, but no fossa in the skull. 



19. Argyropelecus hemigymnus. Handrick ('01). 168 In the 

 adult of this form both the pineal and parapineal organs appear 

 to be present. The pineal organ has a thin stalk and a large 



