This environment lets you explore two different forms of spiral, Archimedean and logarithmic. For each choice of base, look carefully at the points at which the spiral crosses the axis. Now try this when you dilate the spiral. Explain the difference between the two spirals. Can you figure out why the logarithmic spiral is called that? There are sea animals that grow in the form of logarithmic spirals. Can you suggest a reason why this might be the case?