The cells of living leaves and flowers can be prepared for examination in toto by replacing the intercellular air with physiological salt solution. This is done by mounting all or parts of leaves and flowers in salt solution and subjecting the preparation to a vacuum of close to 0.1 μ of mercury. The solution is allowed to boil a few moments, the vacuum is slowly released; then the tissues are ready for examination. Preparations in many ways far superior to chemically cleared mounts can be made in one minute.