Kokshaysky, N. V. (A. N. Severtzov Institute of Animal Evolutionary Morphology and Ecology, Academy of Sciences USSR, Leninsky Prospekt 33, Moscow W-71, USSR) 1974. Functional Aspects of some details of Bird Wing Configuration. Syst. Zool. 22: 442–450.—In four species of herons with uniform ecological requirements of flight, size-induced differences in values of circumferential wing velocities (and, as a result, increasing angles of incidence in distal sections of the wing with increasing body size) are discovered. To neutralize this departure from dynamic similarity among the four species, regular sizelinked departure from geometric similarity develops; this departure manifests itself most obviously in the appearance of wing-tip slots, growing in number with increase in bird size. These slots are an adaptation for utilizing large angles of incidence and for redistributing generated values of thrust and lift. From the viewpoint of the concept of evolutionary transformation of functions, these relationships may be referred to the principle of the evolutionary stabilization of functions.