Imperium naturæ C. Linnaeus, 1758 - nature
   Mundus Plinius - physical world
     naturalia - natural bodies
       Regnum Animale C. Linnaeus, 1758 - animal kingdom see Kingdom Animalia Linnaeus, 1758
         Class Mammalia Linnaeus, 1758 - mammals
           Quadrupedia Linnaeus, 1758 see Class Mammalia Linnaeus, 1758
             Order Belluæ Linnaeus, 1758
               Genus Eqvus Linnaeus, 1758 see Genus Equus Linnaeus, 1758
                 Eqvus asinus Linnaeus, 1758 see Equus asinus Linnaeus, 1758
                   1 [Eqvus asinus var. 1]
                   2 Eqvus asinus var. 2 - mule
                   3 Eqvus asinus var. 3 - hinny