The proximodistal determination of skeletal parts in the developing chick leg.

Currently the chick leg bud or its components are being used extensively to study questions in development. Although fate maps of the leg, similar to that developed by Saunders (1948) for the wing, have been available (Hampé, 1957 a, 1959), no study of the proximodistal sequence of the specification of leg structures exists. Such a sequence developed for the wing by removal of the apical ectodermal ridge at successive stages (Saunders, 1948; Summerbell, 1974), has proven useful to the study of wing development. In this paper, we present a similar proximodistal sequence for the chick leg including the same developmental stage range as that of the wing sequence.