The phylogeny of the polarization compass

Fig. 1:

The polarization-sensitive dorsal rim area of a cricket. Upper panel: Photograph of the dorsal part of a cricket head. Since the POL-ommatidia of crickets lack screening pigment, the dorsal rim area appears whithish. Lower Panel: Histological section through the dorsalmost part of the compound eye showing both unspecialized (left) and POL-ommatidia (right).