How Do Flatlanders Move?

None of this actually explains how Flatlanders move. We know various things about their locomotion; that travelling somewhere involves some form of effort, that it is harder to travel North than in other directions, especially for women, and that femails "undulate" as they travel, although this is more of a safety measure than a necessity. A mundane explanation, but one that causes a few problems, is the use of very short cilia-like mobile hairs for propulsion. This assumes that Flatland ai...

 Evolution of the Eye

A possible sequence of such changes begins with simple eyespots made of light-sensitive pigment, as seen in flatworms. The skin then folds in, forming a cup that protects the eyespot and allows it to better localize the light source. Limpets have eyes like this. In the chambered nautilus, we see a further narrowing of the cup’s opening to produce an improved image, and in ragworms the cup is capped by a protective transparent cover to protect the opening. In abalones, part of the fluid in t...