With the aid of the electron microscope, it has been possible to demonstrate that the configuration of keratohyalin in rat tongue epithelium is highly variable. The configurations described by others are seen, i.e., the globular or irregular granules made up of homogeneous electron-opaque material. In addition to these, there are two other types of granules. One type is constituted heterogeneously of material similar in density to that usually described and another slightly less dense material. In the other type, keratohyalin is arranged as a dense rim around an electron-translucent, amorphous center. In addition to the cytoplasmic keratohyalin granules, intranuclear dense granules were demonstrated. The morphology of these intranuclear granules is similar in some ways to cytoplasmic keratohyalin.