[To some aspects of iris morphology in vertebrates (author's transl)]

The multiplicity of colorations and patterns in the irides as well as the pupillary polymorphism in vertebrates are impressing. They show the iris as an ocular part especially inclined to evolutional modifications. Species from different classes of vertebrates not uncommonly show very similar characteristics of iris morphology provided their mode of life is comparable with regard to relevant factors. On the other hand there exist many examples of very differing iris characteristics in spite of seemingly well corresponding habits of life. These cases often enough pose problems concerning the biological value of a specific variant form. They point however to a multifactorial conditioning of these phenotypic characteristics indicating simultaneously possibilities to create identical effectivities by differing means.