| Abstract: | The eye of a typhloplanid flatworm was investigated by electron microscopy. It consists of a silvery unicellular optic cup similar to a cockscomb flower and of three photoreceptors. The cup is made up of a cell containing reflecting crystalline platelets, arranged in parallel rows inside four laminae. Each photoreceptor is provided with a rhabdomeric photoreceptoral process, some lateral cytoplasmic projections, and an axon. The microvillar border faces medially and makes contact with a reflecting lamina. This eye could discriminate light direction. |
