The mosaic pattern of the inner surface of vertebrate retina.

Retinas of various vertebrates (bullfrog, crow, bull, pig and human) were treated with HCl and collagenase for removal of the basement membrane. The exposed basal surface of Müller cells was observed under a scanning electron microscope. In the nerve fiber layer, the Müller cells divide into small basal processes which extend towards the basal surface, where they terminate with a mosaic pattern. This pattern varies somewhat from species to species and from region to region of the retina.