Psychologists Alliston Reid and John Pilley of Wofford College in Spartanburg, S.C., wanted to test if there was a limit to the amount of words a border collie could learn, so they taught Chaser the names of hundreds of toys, one by one, slowly and patiently, for three years.
http://www.foxnews.com/scitech/2010/12/23/worlds-smartest-dog-knows-words
