Samuel Bostaph said:  
> If you recall, Bob Hebert presented a very amusing paper at the SEA several  
> years ago (and I think it was subsequently published) asking why dogs would  
> trade one bone for another anyway.  
  
  
Recall also Edwin Cannan comment on WoN I.II: "It is by no means clear what   
object there could be in exchanging one bone for for another."  
  
Nicholas Theocarakis