Topography of the retina in the elephant Loxodonta africana.

The distribution of neurones in the ganglion cell layer of the retina of an African elephant is described. The eye was obtained post-mortem from an infant animal, which died of an unknown disease. It is assumed that most of the neurones observed in the ganglion cell layer are ganglion cells. Ganglion cells concentrate along a horizontal axis extending across the retina inferior to the optic disc, as in the visual streak described in the retina of many mammals. They also concentrate in the upper temporal retina, in a pattern distinctive to elephants. We suggest that this latter concentration has evolved to monitor the animal's trunk. Features of the eye, including its size, orientation and fundal pigmentation, are also described.