The last leaf shows the process in its extreme degree. As we glance back and along the whole series of development, we recognize that the form of the last leaf is already indicated in that of the first. It appears as if the form has gradually come to the fore through certain forces which have increasingly prevented the leaf from filling in the whole of its ground-plan with matter. In the last leaf the common plan is still visible in the distribution of the veins, but the fleshy part of the leaf has become restricted to narrow strips along these veins.