Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         "crystal-kingdom"
           chemical substances
             chemical compounds
               Class alcohols [ROH (R≠H)]
                 Class sterols
                   cholesterol [C27H46O; 1~[CH2]2CH(OH)CH2C(~2)=CHCH2CH(~3)CH(~4)C(CH3)(~1)(~2)CH2(~4)CH2C(CH3)(~5)CH(~3)[CH2]2CH(~5)CH(CH3)[CH2]3CH(CH3)2]