A visograph is the primary tool utilized for displaying still or moving images. The key to visograph technology is a direct descendant of such creatures as chameleons and octopi. These creatures utilize an organ within their skin, known as chromatophores, to change their pigment at will. Dr. Leon Pritchard successfully mimicked the technique by excitation of tincture sacs suspended in a liquid medium. He named these cells trichromophores. Just like in chromatophores, sets of colored membranes expand or shrink to provide a predetermined color within the cell. Linking thousands of these cells together and giving each cell specific color instructions every 100th of a second the cells drive the illuminated screen to display static or motion pictures. Subsequent to Pritchard�s first prototype new developments have allowed for the biological growth of arrays of trichromophores in a display lattice as easily as a doctor can grow artificial skin. Phosphoric chemicals and custom enzymes lead to the development of the light emitting quadrachromophore which are utilized in today�s standard visograph display screens.