Full Idea
We don't have one concept of birds formed by learning from exemplars, and another concept of birds that is used in induction.
Gist of Idea
The concept of birds from exemplars must also be used in inductions about birds
Source
Gregory L. Murphy (The Big Book of Concepts [2004], Ch.13)
Book Reference
Murphy,Gregory L.: 'The Big Book of Concepts' [MIT 2004], p.496
A Reaction
In other words exemplar concepts break down when we generalise using the concept. The exemplars must be unified, to be usable in thought and language.