activerecord - Rails: Questiona bout polymorphic associations -

I have 4 models with which I am working: base, state, feature and element.

A base has many figures, many features or many elements, but only one in three (many figures in the base and there are many features for example).

Do the relations look like these models? Am I trying to do as well? If possible, I would like to avoid something like this:

  is base_mount: statistics are_main: attributes are_moin: element    
 
 
 There are several states in the base  
 Fieldbase is derived from base and I have many features  
 elementbase is found from base and there are many elements < / Li>  
 But this is not really a rail question, but an OODZIN is one