Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         "crystal-kingdom"
           chemical substances
             chemical compounds
               Class carbohydrates [Cn(H2O)n, etc.]
                 Class saccharides
                   Class monosaccharides - sugars
                     Class ketoses [H[CHOH]nC(=O)[CHOH]mH, etc.]
                       dihydroxyacetone [C3H6O3; HOCH2C(=O)CH2OH]