Fig. 9

Zygomorphic (left image) and peloric forms (two right images) of the snapdragon crossed by Darwin and cited by him in 1868. The peloric form was fertile and hereditary. The peloric deviation from the normal zygomorphic form in flower morphology was, according to Stubbe [21], discovered in 1742 and described by Linné (1744) in Linaría (toadflaxes and snapdragons), and was one of the first observations in the plant Kingdom raising doubt about the constancy of species (or as Línné had once put it: “Species tot numeramus, quot diversae formae in primítione sunt creatae” (there are as many species as forms first created)