eubacteriales: one of two usually recognized orders of true bacteria; Gram-positive spherical or rod-shaped forms; some are motile; in some classifications considered an order of Schizomycetes
group: any number of entities (members) considered as a unit
shape constancy: the tendency to perceive the shape of a rigid object as constant despite differences in the viewing angle (and consequent differences in the shape of the pattern projected on the retina of the eye)