   These ten genera exist and are to some degree unformed. They are formed into subalternate genera and species by the addition of differentia. Species are formed into individuals by the addition of accidental forms: "a species is nothing other than a formed genus, an individual nothing other than a formed species" (P3; Marenbon 2004: 33; Iwakuma 2004: 309; Fredborg 1977: 35). This is how the view gets its name. The genus exists as the matter. The difference forms the genus "into a sub-altern genus which in turn becomes the matter for an inferior sub-altern genus or species. The addition of accidental forms divides the species into discrete individuals" [et fiant res discretae in actu rerum] (C8; Iwakuma 1999: 103). The individuals in a species or genus thus share a single material essence.