The transfer of monolayers of proteins to solid surfaces from a liquid substrate is now a well‐established procedure. It has been found that if particulate matter is present in the protein solution from which the monolayer is to be formed, the surface streaming set up by the spreading of the protein over the surface of a liquid substrate causes the particles to be distributed uniformly throughout the available surface. They can then be transferred to a solid surface along with the protein monolayer. This procedure has been used in the preparation of specimens for electron microscopy by raising previously immersed collodion‐coated wire mesh screens, attached to glass microscope slides, through the interface occupied by the monolayer. Micrographs of viruses, bacteria, and other bodies mounted in this manner have been obtained. The method commends itself by virtue of the simplicity of the procedure, the uniform dispersion of the particles, the elimination of interference from extraneous dissolved substances, and the high quality of the micrographs obtained.