THE EYES OF INSECTS 



119 



the eye-spot is also carried forward with the lenticular parts of the ocelli. 

 Before the final moult to form the imago is completed, the remnants of 

 the ocelli recede from the surface, and the pigment area which is the 



Fig. 



8l — Vertical Section through a Small Part of an Adult Compound 

 Eye of Dytiscus Marginalis. (After Gunther.) 

 bas. c. : basal cell. pig. : pigment cells. 



rudiment of the compound eye, becomes circular in outline, spreading 

 over the place which was originally occupied by the ocelli. These do not 

 disappear completely, but remain through life as closed pigmented vesicles 

 which are attached to the optic nerves. 



