The growth of Ge islands on Si (Stranski-Krastanov growth mode) is well known (I.N. Stranski, L.v. Krastanov, Akad. Wiss. Wien, Math.-Naturw. Kl. Abtlg. IIb 146 (1937) 797). At larger Ge coverages the islands coalesce and form a quasi two-dimensional film. We investigated this transition from island growth to quasi two-dimensional films for a rather high Ge deposition rate of 0.25 nm/s. The germanium islands were grown by molecular beam epitaxy. At mean thicknesses of 1.25 and 3.75 nm the surface morphology of Ge depositions was observed by atomic force microscopy as a function of deposition temperature. At temperatures between 500 and 550 degrees C, we confirm the 3D-island growth as expected from the Stranski-Krastanov growth mode. But below these temperatures the islands coalesce and form a continuous film (E. Kasper, H. Jorke, J. Vac. Sci. Technol. A 10(4) (1992) 1927). The waviness of the films decrease with decreasing temperatures resulting in smooth layers at 300 degrees C growth temperature.