[The morphology of the iris (author's transl)].

Scanning electron microscopy provides new information about the ultrastructure of the iris. The anterior surface of the iris, oriented towards the anterior chamber, is covered with a single layer of mesenchymal cells. Openings between the dendrite-like branching extensions of these cells form communicating channels between anterior chamber and stroma. The collagen fibres of the iris stroma are organized as rather tightly packed two-dimensional networks. The meshes of these networks form channels, oriented in an anterior-posterior direction, reaching the vessels of the iris. These vessels are wrapped by a tightly packed fibrous coating, consisting of collagen fibres which embrace the vessels in a helical fashion. It is assumed that the transiridial convection current acts as part of a temperature regulating mechanism.