Induction of pinocytosis in Amoeba proteus is independent of adhesion. It is manifested by non-adhering floating specimens, as well as by amoebae moderately adhering and locomoting on the glass, or tightly attached to the polylysine-coated substratum. The formation of pinocytotic rosettes results in de-adhesion, at the beginning of pinocytosis on the glass, but at its end on the polylysine. It suggests an opposition between adhesion and cell shape transformation. Pinocytosis and adhesion are both inhibited, by an unknown mechanism, in the presence of gelatin either in the substratum or in solution.