Abstract
Chromosonial studies have elucidated phylogenetic relations inDrosophila(White, 1954), culicids (Jucci, 1952) and chironomids (Bauer, 1936, 1945). Since it appeared promising to apply this approach to the Simuliidae, Rothfels and Dunbar (1953) began a cytological survey of the black flies of eastern Canada during the summer of 1951. They found that in this group the giant salivary gland chromosomes provided “a wealth of descriptive morphological detail in their number and gross morphology, in the characteristics of expanded centromere regions, in the location of specific nucleolar sites, in the degree of pairing of constituents, and in the ultimate discernible banding pattern…. Since these features are not functionally related to the external environment, the confusing effects of convergence are minimized, resemblances may be taken to indicate relation, and grouping is possible according to natural affinities” (Rothfels and Dunbar, 1953).