A fern gives an interesting illustration of the self-similarity idea of fractal. With a little imagination, we can see that the structure of the whole frond of this fern is (approximately) replicated in each of the frondlets which constitute the frond. In turn, each of the smaller frondlets is made up of 'sub-frondlets' with a similar structure. In the case of a true fractral, this replicating structure continues indefinitely.
