We study the configuration of a typical highly excited string as one slowly increases the string coupling. The dominant interactions are the long-range dilaton and gravitational attraction. In four spacetime dimensions, the string slowly contracts from its initial (large) size until it approaches the string scale where it forms a black hole. In higher dimensions, the string stays large until the coupling reaches a critical value, and then it rapidly collapses to a black hole. The implications for the recently proposed correspondence principle are discussed.

• Received 31 July 1997

DOI:https://doi.org/10.1103/PhysRevD.57.2557