The development was studied of embryos in which dramatic deformations were produced by physical means during the period in which they are highly susceptible to teratogenesis. 2. In spite of the deformations histogenesis as a whole as well as cytodifferentiation seems to be normal. 3. With only few exceptions the embryos showing dramatic deformations ultimately recover a normal morphology. 4. The shape recovering capacity raises the question whether morphogenesis and shape are not in fact more or less independent phenomena.