The incisions of lamina develop at the margin of lamina and progress towards the mid rib and divide the lamina into several miniature leaf like structures called leaflets arranged like feather of a bird on both sides of the rachis in one of the following plants.
In pinnate compound leaves as in case of neem, the incisions progress from margin towards the mid rib and touch the mid rib to form several leaf lets arranged line feather of a bird on both sides of rachis. In palmate compound leaves as in silk cotton, the incisions progress towards the lamina base and fuse to form two or more leaflets that are arranged over the petiole like fingers of our palm.