Uexküll’s Figure 16: The Snail’s Moment

From Jakob von Uexküll’s A Foray into the Worlds of Animals and Humans:

“A snail [Helix pomatia] is placed on a rubber ball which, because it is floating on water, can slide freely past beneath the snail. The snail’s shell is held in place by a clamp. The snail is thereby free to crawl and also stays in the same place. If one places a small stick at the foot of the snail, it will crawl up on it. But if one strikes the snail from one to three times a second with it, the snail will turn away. However, if the blows are repeated four or more times a second, the snail begins to crawl on the stick. In the snail’s environment, a stick that moves back and forth four or more times a second must be at rest. We can conclude from this that the perception time of the snail takes place at a speed of between three and four moments a second. This has a result that all processes of motion take place much more quickly in the snail’s environment than they do in our own. Even the snail’s own movements do not seem slower to it than ours do to us” (72).