Tests of seed buoyancy and viability of wild cotton seeds in experimental tanks of salt water indicate that the upper time limit for buoyancy is a little over 2 mo. This is sufficient to effect transport over relatively short distances (off-shore islands) but totally inadequate for trans-oceanic dispersal. The seeds of the Hawaiian wild sp., Gossypium sandvicense Parl. have sufficient tolerance to salt water immersion to have been carried from the Central American mainland to their present location (required period - 9 mo.) accepting the theory of "rafting". Seeds of other wild forms (G. hirsutum L.) in the Southern Pacific lacked the degree of salt water tolerance required to reach their present locations (Marquesas, Samoa) by surface drift. Reasons suggesting that these forms originated in Central America and reached their present locations by some route other than the South Pacific Equatorial Current are presented. The seeds of neither G. herbaceum var afrieanum Hutchinson nor G. anomalum Wawra and Peyr. (relatives of the diploid parents of New World cottons) appear to have sufficient salt water tolerance to survive a trans-Atlantic crossing.