Controversy exists over whether there is any connection between children's babbling and the development of the adult sound system. The classic proponent of the discontinuity school is Jakobson 1941/1968, who claimed that the pairing of sound and meaning drastically alters the child's sound system. Jakobson's arguments for discontinuity are here evaluated on the basis of data on the transition from babbling to speech in a single set of children recorded weekly in two contexts: mother-child interaction and solitary play. Using the data from the mother-child context, and comparing the sound system of babbling with that of the early words in terms of the distribution of consonants, vocalization length, and phonotactic structure, we find striking parallelism between babbling and words within each child, across time and within time period. The data constitute strong evidence for continuity.*