Both the contour elements and the segment-remnant elements are now needed in identifying an utterance, for each represents features of the utterance not indicated by the other.
- Harris (1951), a pag.56

[…] the unit-segment elements and the contour elements have been established in quite different ways. The unit-length elements resulted from operations of substitution […], whereas the contour elements express limitations in the variety of succession of features of segments.
- Harris (1951), a pag.56, n.20