228 



Journal of Comparative Neurology, 



where the sections of the prisms appear as polygonal areas 

 (Fig. 4), but is not so readily demonstrated in sagittal sections. 





a 



Explanation to I^t^. 5. This figure represents a portion of a sagittal section 

 of a larger complex eye with a heavily pigmented retina. This retina was killed in 

 the light and shows the long pigment cells well projected into the vitreous body. 

 The prismatic structure of the vitreous body is not shown but the smaller lines 

 seen in it and marked SPJ? represent the rods from the short pigment cells. 

 Some of these rods are seen to extend into the shrinkage space SIf. L — lens ; 

 C — capsule; VB — vitreous body ; LP — long pigment cell ; SP — short pigment 

 cell; R — rod from a long pigment cell seen in this case to pass into the cap- 

 sule ; NL — nucleus of a long pigment cell ; NS — nucleus of a short pigment 

 cell ; NT — nerve tissue ; SH — shrinkage space ; S — space about rods of long 

 pigment cells. 



As Conant suggests, each prism is evidently a continuation, 

 a part, of a short retinal cell and not simply a secretion from 



