Natura - nature actualia - actual entities Mundus Plinius - physical world naturalia - natural bodies "crystal-kingdom" chemical substances chemical compounds Class glycoconjugates Class glycopeptides [carbohydrate-peptide] Class glycoproteins [carbohydrate-protein] Class immunoglobulins - antibodies Class immunoglobulin G 1 Class immunoglobulin G1 2 Class immunoglobulin G2 3 Class immunoglobulin G3 4 Class immunoglobulin G4