It does indeed grow very slowly - especially when the tail is visible. Use the pulldown menu to make the tail invisible and it will speed up a lot. Click the recalc button to cause the program to start from scratch again. You may need to do this to get the image started the first time.

You may wonder what's going on here. Actually it's a semi-random process which mimics in a very simple manner certain types of natural growth and in the process generates a fractal. The idea is to start with a single point in the centre of the screen. Let's call it the growth mass. Another point is then released from a randomly chosen point on the outside rectangle and then made to move randomly one step up, down, left or right again and again until one of two things happens. Either the point goes out of bounds in which case we discard it and start over from the edge or it touches the growth mass and sticks there and enlarges the growth mass. In this case too we start another point from the edge.

As you can see the growth mass in the centre gets larger and larger as branch-like arms form and trap the points before they get close to the centre. Every time you run the program a different image results, but they are always very similar looking. This is caused by the strict rules under which the growth occurs.

[Caution: calculation and drawing may also occur when you are off page]