Curve of the fruit length of Oenothera lamarckiana

From the blog Scientific Illustration and Eyeball Mansion showing curves emphasizing the size (length) distribution of the Evening-Primrose (Oenothera lamarckiana). Drawing by botanist and geneticist Hugo de Vries. The top view is a cumulative distribution function flipped by ninety degrees (called by NIST the percent point function). The bottom view shows a larger sketched bell-shaped curve that is just a multiple of the smaller.