PINEAL EYE IN LAGERTILIA. 189 



External to this lies a series of cone-shaped bodies [Co.), the 

 pointed internal ends of which abut against the molecular layer, 

 their broader external extremities being placed against the 

 limiting membrane of the eye, where a certain amount of 

 pigment {pig}) is deposited in the form of fine granules. 



In some cases a connection (not well drawn in the figure) can be 

 traced between the cones and the rods, or,in other cases, the spheri- 

 cal elements. This connection is best developed in the optic axis. 



Epiphysis. — In a preliminary communication to the Royal 

 Societyi the eye of one specimen of V. bengalensis was de- 

 scribed as connected with the brain by a hollow epiphysial 

 stalk. Further investigations have shown that this statement 

 must be modified. It is by no means easy to determine the 

 point, and possibly with a fresh specimen a connection between 

 the eye and the proximal portion of the epiphysis may be shown 

 to exist. The two come very close together (closer than is 

 represented in fig. 17), and there is a decided appearance of a 

 connection between them. Further study of my sections has 

 failed to establish the point, and fig. 17 represents, as far as 

 can at present be ascertained, the actual state. 



The epiphysis (fig. 41) may be divided into three parts : (1) 

 the distal, separated off as the pineal eye ; (2) a short, hollow, 

 proximal portion, arising from theroof of thethalamencephalon, 

 and running at right angles to this ; and (3) a median portion 

 running forward from the end of the latter along the roof of 

 the cranial cavity enclosed in the brain membranes. This part 

 also is hollow, and its walls consist of a single layer of distinctly 

 nucleated columnar cells. Its distal extremity lies immediately 

 beneath the pineal eye, and is swollen out and filled with blood- 

 corpuscles, the cells in the wall of this part being somewhat 

 cubical in shape. Passing backward the walls approach one 

 another until they come into contact, and for a short distance 

 a solid stalk is formed ; further back, again, the walls part 

 from each other, and in this region the cells lengthen out very 

 much until they pass into the proximal part (fig. 41). 



' ' Proc. R. S.,' " Preliminary Communication on the Structure and Pre- 

 sence in Splienodon and other Lizards of the Median Eye, described by de 

 Graaf in Anguis fragilis," June 10th, 1886. 



