The following article, reformatted and copy edited at the lDB Editorial Office with the help of Klaus ander, is Viktor Hamburgers translation of the original 1924 paper by Hans Spemann and Hilde Mangold entitled: Uber Induktion von Embryonalanlagen durch Implantation artfremder Organisatoren", published in Archiv fir Mikroskopische Anatomie und Entwicklungsmechanik, 638, 1924.This translation firstappeared in"Foundations of Experimental Embryology"(B H Willier ndJ. M. Oppenheimer, eds ) Prentice Hall, Inc, Englewood Cliffs, N.]. USA, Pp. 146-184, 1964.The Ilustrations were taken from the original article in germanThe following article, reformatted and copy edited at the IJDB Editorial Office with the help of Klaus Sander, is Viktor Hamburger´s translation of the original 1924 paper by Hans Spemann and Hilde Mangold entitled: "Über Induktion von Embryonalanlagen durch Implantation artfremder Organisatoren", published in Archiv für Mikroskopische Anatomie und Entwicklungsmechanik, 100: 599- 638, 1924. This translation first appeared in "Foundations of Experimental Embryology" (B.H. Willier and J.M. Oppenheimer, eds.), Prentice Hall, Inc., Englewood Cliffs, N.J. USA, pp. 146-184, 1964. The illustrations were taken from the original article in German