as determinant of attention, [94];
as cue to distance, [127];
perception of visual, [132] ff.;
of eyes, in optical illusion, [136] f.;
instinctive, [204] ff.;
expressive, [222] ff.;
differentiates plant from animal, [230] f.;
distinguished from action, [231];
unreliable index of mental processes, [232] f., [323];
‘sensations of intended movement,’ [241];