White-eyed Mutants of Diptera

Abstract

RECENTLY, Sturtevant¹ has criticized work on white-eyed mutants of Culex², Calliphora³ and Phormica (= Phormia)⁴, on the grounds that such mutations are not comparable with white-eyed types in Drosophila. Sturtevant claims that while there are two pigments, a red and a brown, in the wild-type eye of Drosophila, there is only one pigment, a brown, in Calliphora, and that this is the usual condition in insects. Thus, the wild-type eye of Calliphora would be like the brown mutant of Drosophila in which red pigment is absent; and, moreover, in that case it would not be possible to distinguish morphologically white, vermilion, cinnabar and scarlet mutants in Calliphora or in other Diptera in which red pigment is not present in the wild-type eye. In support of this view, Sturtevant quotes the work of Becker⁵ on the eye-pigments of Arthropods.