Print CLXI

Key to cancer types shown by spheres in the spacetime diagrams (Colour).

Ray-traced spheres are shown, lit from the top-left. An artefact of the printing process occasionally causes darker strips to be drawn across the page.

The nine groups of cancers are the amalgamations of the lists shown here. It is not easy to discern more than this number of distinct colours along with the effects of shadow and the angle of the light source.

First print from a series of six.