The paper analyzes the possibility of describing morphological features in the B2→B19 transformation in the framework of a dynamic theory based on the concepts of heterogeneous nucleation and wave growth of martensite crystals. It was shown, using TiNiCu alloys as an example, that the predicted and observed orientations of habit planes agree well. The issue that strain ratios remain valid in going from threshold to final strains is considered, and calculation results for orientation relations and their fulfilment conditions are discussed.