Normal mouse fibroblasts in culture were enucleated by centrifugation in a cytochalasin B-containing medium and then incubated with Con A. Bound Con A was determined by the indirect immunofluorescence technique. Such incubation led to the redistribution of the Con A receptors on the surface from the periphery towards the center both in enucleated cells and in small cytoplasmic fragments. Thus the capping of the cross-linked receptors was shown to be independent of the nucleus presence in the cell. Large cytoplasts contained both microfilaments and microtubules. Meanwhile small fragments demonstrated only microfilaments. Colcemide that destroys microtubules did not affect the redistribution of the Con A receptors. It is suggested that microfilaments rather than microtubules are responsible for the redistribution in question.