The Experiment

Abstract

They looked like tiny sausages, and never had I been so pleased to see a sausage. They were actually little pieces cut out from frog embryos, so small that they could only be seen clearly down a microscope. Normally, such small clumps of cells will round up into balls and stay that way for several days, remaining alive but in a very inscrutable way, as they do not do anything much to attract the observer’s attention. But the ones I was looking at had elongated into sausages. I knew that their unusual shape was due to their having been treated with a protein we had purified from cows’ brains. I also knew that the elongation I saw meant that the cells were developing in a different way from usual and that they would decisively change the course of my future work.