Slide showing two diagrams of the 'Eye of Nereis'. Slide shows two diagrams of the 'Eye of Nereis'. Diagram 'a' is labelled with the letters 'c','e','l','h','r','n'. Diagram 'b' is labelled with the letters 'h','p','c','f'. There is a corresponding key which reads as follows: 'Fig. 130. - Eye of Nereis. (After Andrews.) x150. A, Section through the entire eye; c, cuticle; e, epidermis; l, lens; h, rods; r, retina; n, optic nerve: B, isolated retinal element; c, cell; p, pigment; h, rod; f, nerve-fibre.' Nereis: polychaete worm. Late 19th to early 20th century