[size=150]Escher begins to work on hyperbolic geometry using the model of the halfplane near 1956. After some transitional works, it's in the drawing [i]Regular Division of the Plane VI[/i] (1957) that we can see the geometry more clearly. The tesselae almost adjust the lines (geodesic) in the halfplane, which should coincide with the lower side of the lizards.[br][br]A beam of parabola in sky blue color, marks the spine of the first rows tessellated with lizards.[/size]