An exhibit in London plans to showcase anti-Israel and anti-Semitic cartoons and imagery from 15th century Germany to modern-day Palestinian cartoons, including Jewish snakes and Prime Minister Ariel Sharon eating a Palestinian baby. But the images being used are from a Jewish doctor's private collection. “What's the boundary between legitimate political criticism and racist propaganda? It is difficult to determine,” said Simon Cohen, the doctor putting his collection on display. Cohen is mounting the exhibition to show the public the persistence of anti-Semitic images over the centuries. He said that anyone who failed to see the Sharon cartoon as anti-Semitic is ignorant of the history of “blood libels,” images that cast Jews in a negative light.