Muller (1998) develops a language of motion and shape change in terms of topological relations and temporal order relations between regions of space-time (histories). He uses this language to state and prove the transition rules developed in (Randell, Cui, and Cohn, 1992) that constrain the changes in spatial relations possible for objects whose shape changes continuously. Unfortunately, Muller's statement of the transition rules is inadequate. This paper presents an alternative statement of these transition rules.