Unique eye of probable evolutionary significance

Science  13 Mar 1981:
Vol. 211, Issue 4487, pp. 1189-1190
DOI: 10.1126/science.7466394


The eyes in the brain of a larval flatworm studied by electron microscopy are dissimilar. Light-sensitive structures in the right eye are microvilli; those in the left eye, the unique one, are both microvillar and ciliary. Perhaps this is evidence for the origin of a microvillar line of photoreceptoral evolution from a more primitive ciliary line.