Optical Fourier transformns, made of electron mnicrographs of the crystalline array of ribonucleoprotein known as chromatoid bodies of Entamoeba invadens, have been interpreted as the transforms of a helix of 12 nodes in five turns. A model shows that this helix may be built of spheres 180 angstroms in diameter, placed at a radius of 150 angstroms. The optical transform of the model is very similar to the transform of the original electron micrograph.