97 



According to Chilton, '94, tlie degeneration of the eyes of crustaceans 

 may follow one of three lines. We may have — 



1. Total atrophy of optic lobes and optic nerves, with or without the 

 persistence in part of the pigment or retina and the crystalline lens. 



2. Persistence of optic lobes and optic nerves, but total atrophy of 

 the rods and cones, retina (pigment), and facets, or. 



