The paintings of algae seem to glow with a greenish light, the slender fronds rendered with painstaking detail at up to 1,000 times actual size.
The eye of 19th-century artist Cornelius Varley was involved in creating the images, but something else was at work:
A sophisticated optical instrument that gave him the illusion of seeing the algae right on his canvas.
Think it makes the artist's job easy? Think again.